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Jouma'a J, Orgeret F, Picard B, Robinson PW, Weimerskirch H, Guinet C, Costa DP, Beltran RS. Contrasting offspring dependence periods and diving development rates in two closely related marine mammal species. ROYAL SOCIETY OPEN SCIENCE 2024; 11:230666. [PMID: 38179081 PMCID: PMC10762441 DOI: 10.1098/rsos.230666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 11/23/2023] [Indexed: 01/06/2024]
Abstract
Understanding the ontogeny of diving behaviour in marine megafauna is crucial owing to its influence on foraging success, energy budgets, and mortality. We compared the ontogeny of diving behaviour in two closely related species-northern elephant seals (Mirounga angustirostris, n = 4) and southern elephant seals (Mirounga leonina, n = 9)-to shed light on the ecological processes underlying migration. Although both species have similar sizes and behaviours as adults, we discovered that juvenile northern elephant seals have superior diving development, reaching 260 m diving depth in just 30 days, while southern elephant seals require 160 days. Similarly, northern elephant seals achieve dive durations of approximately 11 min on their first day of migration, while southern elephant seals take 125 days. The faster physiological maturation of northern elephant seals could be related to longer offspring dependency and post-weaning fast durations, allowing them to develop their endogenous oxygen stores. Comparison across both species suggests that weaned seal pups face a trade-off between leaving early with higher energy stores but poorer physiological abilities or leaving later with improved physiology but reduced fat stores. This trade-off might be influenced by their evolutionary history, which shapes their migration behaviours in changing environments over time.
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Affiliation(s)
- Joffrey Jouma'a
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
| | - Florian Orgeret
- Marine Apex Predator Research Unit, Department of Zoology, Institute for Coastal and Marine Research, Nelson Mandela University, Gqeberha 6031, South Africa
| | - Baptiste Picard
- Centre d'Etudes Biologiques de Chizé, UMR 7372 La Rochelle University-CNRS, La Rochelle, France
| | - Patrick W. Robinson
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé, UMR 7372 La Rochelle University-CNRS, La Rochelle, France
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé, UMR 7372 La Rochelle University-CNRS, La Rochelle, France
| | - Daniel P. Costa
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, CA, USA
| | - Roxanne S. Beltran
- Ecology and Evolutionary Biology, University of California Santa Cruz, CA, USA
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Chevallay M, Goulet P, Madsen PT, Campagna J, Campagna C, Guinet C, Johnson MP. Large sensory volumes enable Southern elephant seals to exploit sparse deep-sea prey. Proc Natl Acad Sci U S A 2023; 120:e2307129120. [PMID: 37844247 PMCID: PMC10614626 DOI: 10.1073/pnas.2307129120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 09/08/2023] [Indexed: 10/18/2023] Open
Abstract
The ability of echolocating toothed whales to detect and classify prey at long ranges enables efficient searching and stalking of sparse prey in these time-limited dives. However, nonecholocating deep-diving seals such as elephant seals appear to have much less sensory advantage over their prey. Both elephant seals and their prey rely on visual and hydrodynamic cues that may be detectable only at short ranges in the deep ocean, leading us to hypothesize that elephant seals must adopt a less efficient reactive mode of hunting that requires high prey densities. To test that hypothesis, we deployed high-resolution sonar and movement tags on 25 females to record simultaneous predator and prey behavior during foraging interactions. We demonstrate that elephant seals have a sensory advantage over their prey that allows them to potentially detect prey 5 to 10 s before striking. The corresponding prey detection ranges of 7 to 17 m enable stealthy approaches and prey-specific capture tactics. In comparison, prey react at a median range of 0.7 m, close to the neck extension range of striking elephant seals. Estimated search swathes of 150 to 900 m2 explain how elephant seals can locate up to 2,000 prey while swimming more than 100 km per day. This efficient search capability allows elephant seals to subsist on prey densities that are consonant with the deep scattering layer resources estimated by hydroacoustic surveys but which are two orders of magnitude lower than the prey densities needed by a reactive hunter.
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Affiliation(s)
- Mathilde Chevallay
- Centre d’Etudes Biologiques de Chizé, Centre National de la Recherche Scientifique, Villiers-en-Bois79360, France
| | - Pauline Goulet
- Centre d’Etudes Biologiques de Chizé, Centre National de la Recherche Scientifique, Villiers-en-Bois79360, France
| | | | - Julieta Campagna
- Centro Nacional Patagónico, Centro Científico Tecnológico del Consejo Nacional de Investigaciones Científicas y Técnicas, Puerto Madryn9120, Argentina
| | | | - Christophe Guinet
- Centre d’Etudes Biologiques de Chizé, Centre National de la Recherche Scientifique, Villiers-en-Bois79360, France
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Eder EB, Zárate M, Lewis MN. Light and temperature records of the seawater associated with southern elephant seal dives during foraging trips in South Atlantic and Pacific Oceans. Biodivers Data J 2023; 11:e101284. [PMID: 38362312 PMCID: PMC10868126 DOI: 10.3897/bdj.11.e101284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 04/18/2023] [Indexed: 02/17/2024] Open
Abstract
Background The dataset comprises geolocalised records of dive and surface interval durations, light level and temperature of the seawater during the post-resting and post-moulting tracks of 13 immature southern elephant seals, Miroungaleonina. It describes an unpublished open access version of the original data with records of light level and temperature of the water column using the Darwin Core standard (DwC) through ArOBIS, guaranteeing compliance with the FAIR principles, encompassing a wide time scale (2005, 2006 and 2007) and geographic range in the South Atlantic and Pacific Oceans (South West [-58.75, -81.29], North East [-37.60, -28.65]). Seals were simultaneously equipped with affordable light-temperature loggers (LTLs) and satellite tags. The LTLs recorded light level and temperature of the water column at 30-s intervals during dives and light-time records were applied to estimate dive parameters of diurnal records from 06:00 to 17:00 h, since movements up and down the water column are reflected by changes in light level. For that, the minimum light level reached at the surface of a dive was determined experimentally with diurnal dive simulations at sea using the LTLs devices before deployment. The dataset also includes variation of light and temperature of records between 17:00 to 06:00 h. Data can be used to identify temperature changes associated with seawater masses as drivers of the distribution of other taxa of interest and variation of light level in the seawater (light attenuation) could be linked to concentrations of phytoplankton assemblages as an index of primary productivity. New information This dataset provides unpublished data of the duration of dives and surface intervals and associated records of light level and temperature variations along the movements throughout the seawater of 13 immature southern elephant seals in the Southern Hemisphere. The location data were generated by satellite tags and the light and temperature data were recorded with light-temperature loggers (LTLs), both devices deployed on individuals simultaneously and uploaded following the Darwin Core standard and compliance with the FAIR principles.
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Affiliation(s)
- Elena B. Eder
- Centre for the Study of Marine Systems, Centro Nacional
Patagónico (CESIMAR-CENPAT-CONICET), Puerto Madryn, ArgentinaCentre for the Study of Marine Systems, Centro Nacional Patagónico
(CESIMAR-CENPAT-CONICET)Puerto MadrynArgentina
| | - Marcos Zárate
- Centre for the Study of Marine Systems, Centro Nacional
Patagónico (CESIMAR-CENPAT-CONICET), Puerto Madryn, ArgentinaCentre for the Study of Marine Systems, Centro Nacional Patagónico
(CESIMAR-CENPAT-CONICET)Puerto MadrynArgentina
| | - Mirtha N. Lewis
- Centre for the Study of Marine Systems, Centro Nacional
Patagónico (CESIMAR-CENPAT-CONICET), Puerto Madryn, ArgentinaCentre for the Study of Marine Systems, Centro Nacional Patagónico
(CESIMAR-CENPAT-CONICET)Puerto MadrynArgentina
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Volzke S, Cleeland JB, Hindell MA, Corney SP, Wotherspoon SJ, McMahon CR. Extreme polygyny results in intersex differences in age-dependent survival of a highly dimorphic marine mammal. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221635. [PMID: 36968236 PMCID: PMC10031410 DOI: 10.1098/rsos.221635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/02/2023] [Indexed: 06/18/2023]
Abstract
Developmental differences in vital rates are especially profound in polygamous mating systems. Southern elephant seals (Mirounga leonina) are highly dimorphic and extremely polygynous marine mammals. A demographic model, supported by long-term capture-mark-recapture records, investigated the influence of sex and age on survival in this species. The study revealed clear differences between female and male age-dependent survival rates. Overall juvenile survival estimates were stable around 80-85% for both sexes. However, male survival estimates were 5-10% lower than females in the same age classes until 8 years of age. At this point, male survival decreased rapidly to 50% ± 10% while female estimates remained constant at 80% ± 5%. Different energetic requirements could underpin intersex differences in adult survival. However, the species' strong sexual dimorphism diverges during early juvenile development when sex-specific survival rates were less distinct. Maximizing growth is especially advantageous for males, with size being a major determinant of breeding probability. Maturing males may employ a high-risk high-reward foraging strategy to compensate for extensive sexual selection pressures and sex-specific energetic needs. Our findings suggest sex-specific adult survival is a result of in situ ecological interactions and evolutionary specialization associated with being a highly polygynous marine predator.
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Affiliation(s)
- Sophia Volzke
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, TAS 7050, Australia
| | - Jaimie B. Cleeland
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, TAS 7050, Australia
| | - Mark A. Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
| | - Stuart P. Corney
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
- Centre for Marine Socioecology, University of Tasmania, Hobart, TAS 7005, Australia
- Australian Antarctic Partnership Program, University of Tasmania, Hobart, TAS 7005, Australia
| | - Simon J. Wotherspoon
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, TAS 7050, Australia
| | - Clive R. McMahon
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
- IMOS Animal Tagging, Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
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Allegue H, Réale D, Picard B, Guinet C. Track and dive-based movement metrics do not predict the number of prey encountered by a marine predator. MOVEMENT ECOLOGY 2023; 11:3. [PMID: 36681811 PMCID: PMC9862577 DOI: 10.1186/s40462-022-00361-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 12/17/2022] [Indexed: 06/08/2023]
Abstract
BACKGROUND Studying animal movement in the context of the optimal foraging theory has led to the development of simple movement metrics for inferring feeding activity. Yet, the predictive capacity of these metrics in natural environments has been given little attention, raising serious questions of the validity of these metrics. The aim of this study is to test whether simple continuous movement metrics predict feeding intensity in a marine predator, the southern elephant seal (SES; Mirounga leonine), and investigate potential factors influencing the predictive capacity of these metrics. METHODS We equipped 21 female SES from the Kerguelen Archipelago with loggers and recorded their movements during post-breeding foraging trips at sea. From accelerometry, we estimated the number of prey encounter events (nPEE) and used it as a reference for feeding intensity. We also extracted several track- and dive-based movement metrics and evaluated how well they explain and predict the variance in nPEE. We conducted our analysis at two temporal scales (dive and day), with two dive profile resolutions (high at 1 Hz and low with five dive segments), and two types of models (linear models and regression trees). RESULTS We found that none of the movement metrics predict nPEE with satisfactory power. The vertical transit rates (primarily the ascent rate) during dives had the best predictive performance among all metrics. Dive metrics performed better than track metrics and all metrics performed on average better at the scale of days than the scale of dives. However, the performance of the models at the scale of days showed higher variability among individuals suggesting distinct foraging tactics. Dive-based metrics performed better when computed from high-resolution dive profiles than low-resolution dive profiles. Finally, regression trees produced more accurate predictions than linear models. CONCLUSIONS Our study reveals that simple movement metrics do not predict feeding activity in free-ranging marine predators. This could emerge from differences between individuals, temporal scales, and the data resolution used, among many other factors. We conclude that these simple metrics should be avoided or carefully tested a priori with the studied species and the ecological context to account for significant influencing factors.
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Affiliation(s)
- Hassen Allegue
- Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, QC, Canada.
| | - Denis Réale
- Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, QC, Canada
| | - Baptiste Picard
- Centre d'Etudes Biologiques de Chizé, UMR7372 CNRS-La Rochelle Université, Villiers en Bois, France
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé, UMR7372 CNRS-La Rochelle Université, Villiers en Bois, France
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Cephalopod diet of juvenile male southern elephant seals Mirounga leonina at Marion Island, South Indian Ocean. Polar Biol 2022. [DOI: 10.1007/s00300-022-03070-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Movements of southern elephant seals (Mirounga leonina) from Davis Base, Antarctica: combining population genetics and tracking data. Polar Biol 2022. [DOI: 10.1007/s00300-022-03058-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
AbstractMarine animals such as the southern elephant seal (Mirounga leonina) rely on a productive marine environment and are vulnerable to oceanic changes that can affect their reproduction and survival rates. Davis Base, Antarctica, acts as a moulting site for southern elephant seals that forage in Prydz Bay, but the mitochondrial haplotype diversity and natal source populations of these seals have not been characterized. In this study, we combined genetic and animal tracking data on these moulting seals to identify levels of mitochondrial haplotype diversity, natal source population, and movement behaviours during foraging and haul-out periods. Using partial sequences of the mitochondrial control region, we identified two major breeding mitochondrial lineages of seals at Davis Base. We found that the majority of the seals originated from breeding stocks within the South Atlantic Ocean and South Indian Ocean. One seal was grouped with the Macquarie Island breeding stock (South Pacific Ocean). The Macquarie Island population, unlike the other two stocks, is decreasing in size. Tracking data revealed long-distance foraging activity of the Macquarie Island seal around Crozet Islands. We speculate that changes to the Antarctic marine environment can result in a shift in foraging and movement strategies, which subsequently affects seal population growth rates.
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Negrete J, Juáres M, Mennucci JA, Daneri G. Population status of southern elephant seals (Mirounga leonina) at Peninsula Potter breeding colony, Antarctica. Polar Biol 2022. [DOI: 10.1007/s00300-022-03044-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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Dispersion of a southern elephant seal Mirounga leonina to Possession Island, Namibia. Polar Biol 2022. [DOI: 10.1007/s00300-022-03032-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Arce F, Hindell MA, McMahon CR, Wotherspoon SJ, Guinet C, Harcourt RG, Bestley S. Elephant seal foraging success is enhanced in Antarctic coastal polynyas. Proc Biol Sci 2022; 289:20212452. [PMID: 35078353 PMCID: PMC8790345 DOI: 10.1098/rspb.2021.2452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/02/2021] [Indexed: 01/28/2023] Open
Abstract
Antarctic polynyas are persistent open water areas which enable early and large seasonal phytoplankton blooms. This high primary productivity, boosted by iron supply from coastal glaciers, attracts organisms from all trophic levels to form a rich and diverse community. How the ecological benefit of polynya productivity is translated to the highest trophic levels remains poorly resolved. We studied 119 southern elephant seals feeding over the Antarctic shelf and demonstrated that: (i) 96% of seals foraging here used polynyas, with individuals spending on average 62% of their time there; (ii) the seals exhibited more area-restricted search behaviour when in polynyas; and (iii) these seals gained more energy (indicated by increased buoyancy from greater fat stores) when inside polynyas. This higher-quality foraging existed even when ice was not present in the study area, indicating that these are important and predictable foraging grounds year-round. Despite these energetic advantages from using polynyas, not all the seals used them extensively. Factors other than food supply may influence an individual's choice in their use of feeding grounds, such as exposure to predation or the probability of being able to return to distant sub-Antarctic breeding sites.
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Affiliation(s)
- Fernando Arce
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
- Australian Antarctic Division, 203 Channel Highway, Kingston, TAS 7050, Australia
| | - Mark A. Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
| | - Clive R. McMahon
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
- IMOS Animal Tagging, Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
- Department of Biological Sciences, Macquarie University, North Ryde, NSW 2113, Australia
| | - Simon J. Wotherspoon
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
- Australian Antarctic Division, 203 Channel Highway, Kingston, TAS 7050, Australia
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé, CNRS, Villiers en Bois 79360, France
| | - Robert G. Harcourt
- Department of Biological Sciences, Macquarie University, North Ryde, NSW 2113, Australia
| | - Sophie Bestley
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129 Hobart, TAS 7001, Australia
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Allegue H, Guinet C, Patrick SC, Hindell MA, McMahon CR, Réale D. Sex, body size, and boldness shape the seasonal foraging habitat selection in southern elephant seals. Ecol Evol 2022; 12:e8457. [PMID: 35127010 PMCID: PMC8796948 DOI: 10.1002/ece3.8457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 12/04/2022] Open
Abstract
Selecting foraging habitat is a fundamental behavior in the life of organisms as it directly links resource acquisition to fitness. Differences in habitat selection among individuals may arise from several intrinsic and extrinsic factors, and yet, their interaction has been given little attention in the study of wild populations. We combine sex, body size, and boldness to explain individual differences in the seasonal foraging habitat selection of southern elephant seals (Mirounga leonina) from the Kerguelen Archipelago. We hypothesize that habitat selection is linked to the trade-off between resource acquisition and risk, and that individuals differ in their position along this trade-off because of differences in reproductive strategies, life stages, and metabolic requirements. Before the post-molt foraging trip, we used a novel object approach test to quantify the boldness of 28 subadult and adult females and 42 subadult males and equipped them with data loggers to track their movements at sea. Subadult males selected neritic and oceanic habitats, whereas females mostly selected less productive oceanic habitats. Both sexes showed a seasonal shift from Antarctic habitats in the south in the summer to the free of ice subantarctic and subtropical habitats in the north in the winter. Males avoided oceanic habitats and selected more productive neritic and Antarctic habitats with body size mostly in the winter. Bolder males selected northern warmer waters in winter, while shyer ones selected the Kerguelen plateau and southern colder oceanic waters. Bolder females selected the Kerguelen plateau in the summer when prey profitability is assumed to be the highest. This study not only provides new insights into the spatiotemporal foraging ecology of elephant seals in relation to personality but also emphasizes the relevance of combining several intrinsic and extrinsic factors in understanding among-individual variation in space use essential in wildlife management and conservation.
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Affiliation(s)
- Hassen Allegue
- Département des Sciences BiologiquesUniversité du Québec à MontréalMontréalQCCanada
| | | | | | - Mark A. Hindell
- Institute for Marine and Antarctic StudiesBattery PointTASAustralia
- Antarctic Climate and Ecosystems Cooperative Research CentreUniversity of TasmaniaHobartTASAustralia
| | - Clive R. McMahon
- Institute for Marine and Antarctic StudiesBattery PointTASAustralia
- Sydney Institute of Marine ScienceSydneyNSWAustralia
- Department of Biological SciencesMacquarie UniversitySydneyNSWAustralia
| | - Denis Réale
- Département des Sciences BiologiquesUniversité du Québec à MontréalMontréalQCCanada
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Volzke S, McMahon CR, Hindell MA, Burton HR, Wotherspoon SJ. Climate influences on female survival in a declining population of southern elephant seals ( Mirounga leonina). Ecol Evol 2021; 11:11333-11344. [PMID: 34429922 PMCID: PMC8366891 DOI: 10.1002/ece3.7919] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 06/21/2021] [Accepted: 06/25/2021] [Indexed: 11/22/2022] Open
Abstract
The Southern Ocean has been disproportionately affected by climate change and is therefore an ideal place to study the influence of changing environmental conditions on ecosystems. Changes in the demography of predator populations are indicators of broader shifts in food web structure, but long-term data are required to study these effects. Southern elephant seals (Mirounga leonina) from Macquarie Island have consistently decreased in population size while all other major populations across the Southern Ocean have recently stabilized or are increasing. Two long-term mark-recapture studies (1956-1967 and 1993-2009) have monitored this population, which provides an opportunity to investigate demographic performance over a range of climatic conditions. Using a 9-state matrix population model, we estimated climate influences on female survival by incorporating two major climatic indices into our model: The Southern Annular Mode (SAM) and the Southern Oscillation Index (SOI). Our best model included a 1 year lagged effect of SAM and an unlagged SOI as covariates. A positive relationship with SAM1 (lagged) related the previous year's SAM with juvenile survival, potentially due to changes in local prey availability surrounding Macquarie Island. The unlagged SOI had a negative effect on both juvenile and adult seals, indicating that sea ice dynamics and access to foraging grounds on the East Antarctic continental shelf could explain the different contributions of ENSO events on the survival of females in this population.
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Affiliation(s)
- Sophia Volzke
- Institute for Marine & Antarctic StudiesUniversity of TasmaniaHobartTas.Australia
| | - Clive R. McMahon
- Institute for Marine & Antarctic StudiesUniversity of TasmaniaHobartTas.Australia
- IMOS Animal TaggingSydney Institute of Marine ScienceMosmanNSWAustralia
| | - Mark A. Hindell
- Institute for Marine & Antarctic StudiesUniversity of TasmaniaHobartTas.Australia
- Antarctic Climate and Ecosystems Cooperative Research CentreUniversity of TasmaniaHobartTas.Australia
| | - Harry R. Burton
- Australian Antarctic DivisionDepartment of Agriculture, Water and the EnvironmentKingstonTas.Australia
| | - Simon J. Wotherspoon
- Institute for Marine & Antarctic StudiesUniversity of TasmaniaHobartTas.Australia
- Australian Antarctic DivisionDepartment of Agriculture, Water and the EnvironmentKingstonTas.Australia
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Barbosa A, Varsani A, Morandini V, Grimaldi W, Vanstreels RET, Diaz JI, Boulinier T, Dewar M, González-Acuña D, Gray R, McMahon CR, Miller G, Power M, Gamble A, Wille M. Risk assessment of SARS-CoV-2 in Antarctic wildlife. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 755:143352. [PMID: 33162142 PMCID: PMC7598351 DOI: 10.1016/j.scitotenv.2020.143352] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 04/15/2023]
Abstract
The coronavirus disease 2019 (COVID-19) pandemic is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This pathogen has spread rapidly across the world, causing high numbers of deaths and significant social and economic impacts. SARS-CoV-2 is a novel coronavirus with a suggested zoonotic origin with the potential for cross-species transmission among animals. Antarctica can be considered the only continent free of SARS-CoV-2. Therefore, concerns have been expressed regarding the potential human introduction of this virus to the continent through the activities of research or tourism to minimise the effects on human health, and the potential for virus transmission to Antarctic wildlife. We assess the reverse-zoonotic transmission risk to Antarctic wildlife by considering the available information on host susceptibility, dynamics of the infection in humans, and contact interactions between humans and Antarctic wildlife. The environmental conditions in Antarctica seem to be favourable for the virus stability. Indoor spaces such as those at research stations, research vessels or tourist cruise ships could allow for more transmission among humans and depending on their movements between different locations the virus could be spread across the continent. Among Antarctic wildlife previous in silico analyses suggested that cetaceans are at greater risk of infection whereas seals and birds appear to be at a low infection risk. However, caution needed until further research is carried out and consequently, the precautionary principle should be applied. Field researchers handling animals are identified as the human group posing the highest risk of transmission to animals while tourists and other personnel pose a significant risk only when in close proximity (< 5 m) to Antarctic fauna. We highlight measures to reduce the risk as well as identify of knowledge gaps related to this issue.
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Affiliation(s)
- Andrés Barbosa
- Evolutionary Ecology Dpt. Museo Nacional de Ciencias Naturales, CSIC, C/José Gutierrez Abascal, 2, 28006 Madrid, Spain.
| | - Arvind Varsani
- The Biodesign Center for Fundamental and Applied Microbiomics, Center for Evolution and Medicine, School of Life Sciences, Arizona State University, Tempe, AZ, USA; Structural Biology Research Unit, Department of Integrative Biomedical Sciences, University of Cape Town, Observatory, Cape Town, South Africa
| | - Virginia Morandini
- Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University, Oregon, USA
| | | | - Ralph E T Vanstreels
- Institute of Research and Rehabilitation of Marine Animals (IPRAM), Rodovia, Cariacica, Brazil
| | - Julia I Diaz
- Centro de Estudios Parasitológicos y de Vectores (CEPAVE-UNLP-CONICET), La Plata, Buenos Aires, Argentina
| | - Thierry Boulinier
- Centre d'Ecologie Fonctionnelle et Evolutive, CNRS, Université de Montpellier, EPHE, Université Paul Valéry Montpellier 3, IRD, Montpellier, France
| | - Meagan Dewar
- School of Science, Psychology and Sport, Federation University Australia, Australia
| | - Daniel González-Acuña
- Laboratorio de Parásitos y Enfermedades de Fauna Silvestre, Facultad de Ciencias Veterinarias, Universidad de Concepción, Chillán, Chile
| | - Rachael Gray
- Sydney School of Veterinary Science, Faculty of Science, The University of Sydney, NSW, Australia
| | - Clive R McMahon
- IMOS Animal Satellite Tagging, Sydney Institute of Marine Science, Mosman, New South Wales, Australia
| | - Gary Miller
- Discipline of Microbiology and Immunology, University of Western Australia, Crawley, WA 6009, Australia
| | - Michelle Power
- Department of Biological Sciences, Macquarie University, NSW 2109, Australia
| | - Amandine Gamble
- Department of Ecology and Evolution, University of California Los Angeles, CA, USA
| | - Michelle Wille
- Marie Bashir Institute for Infectious Diseases and Biosecurity, School of Life and Environmental Sciences and School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
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14
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Hindell MA, McMahon CR, Jonsen I, Harcourt R, Arce F, Guinet C. Inter- and intrasex habitat partitioning in the highly dimorphic southern elephant seal. Ecol Evol 2021; 11:1620-1633. [PMID: 33613994 PMCID: PMC7882946 DOI: 10.1002/ece3.7147] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/25/2020] [Accepted: 12/02/2020] [Indexed: 01/15/2023] Open
Abstract
Partitioning resources is a key mechanism for avoiding intraspecific competition and maximizing individual energy gain. However, in sexually dimorphic species it is difficult to discern if partitioning is due to competition or the different resource needs of morphologically distinct individuals. In the highly dimorphic southern elephant seal, there are intersexual differences in habitat use; at Iles Kerguelen, males predominantly use shelf waters, while females use deeper oceanic waters. There are equally marked intrasexual differences, with some males using the nearby Kerguelen Plateau, and others using the much more distant Antarctic continental shelf (~2,000 km away). We used this combination of inter and intrasexual behavior to test two hypotheses regarding habitat partitioning in highly dimorphic species. (a) that intersexual differences in habitat use will not appear until the seals diverge in body size and (b) that some habitats have higher rates of energy return than others. In particular, that the Antarctic shelf would provide higher energy returns than the Kerguelen Shelf, to offset the greater cost of travel. We quantified the habitat use of 187 southern elephant seals (102 adult females and 85 subadult males). The seals in the two groups were the same size (~2.4 m) removing the confounding effect of body size. We found that the intersexual differences in habitat use existed before the divergence in body size. Also, we found that the amount of energy gained was the same in all of the major habitats. This suggests that the use of shelf habitats by males is innate, and a trade-off between the need to access the large benthic prey available on shelf waters, against the higher risk of predation there. Intrasexual differences in habitat use are another trade-off; although there are fewer predators on the Antarctic shelf, it is subject to considerable interannual fluctuations in sea-ice extent. In contrast, the Kerguelen Plateau presents more consistent foraging opportunities, but contains higher levels of predation. Habitat partitioning in this highly dimorphic species is therefore the result of complex interplay of life history strategies, environmental conditions and predation pressure.
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Affiliation(s)
- Mark A. Hindell
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Clive R. McMahon
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
- IMOS Animal Tagging, Sydney Institute of Marine ScienceMosmanNew South WalesAustralia
- Department of Biological SciencesMacquarie UniversityNorth Ryde, SydneyNew South WalesAustralia
| | - Ian Jonsen
- Department of Biological SciencesMacquarie UniversityNorth Ryde, SydneyNew South WalesAustralia
| | - Robert Harcourt
- IMOS Animal Tagging, Sydney Institute of Marine ScienceMosmanNew South WalesAustralia
- Department of Biological SciencesMacquarie UniversityNorth Ryde, SydneyNew South WalesAustralia
| | - Fernando Arce
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Christophe Guinet
- Centre d’Etudes Biologiques de Chizé (CEBC)UMR 7372Université de la Rochelle‐CNRSVilliers en BoisFrance
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15
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Ferreira LC, Thums M, Fossette S, Wilson P, Shimada T, Tucker AD, Pendoley K, Waayers D, Guinea ML, Loewenthal G, King J, Speirs M, Rob D, Whiting SD. Multiple satellite tracking datasets inform green turtle conservation at a regional scale. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Luciana C. Ferreira
- Australian Institute of Marine Science Indian Ocean Marine Research Centre University of Western Australia Crawley WA Australia
| | - Michele Thums
- Australian Institute of Marine Science Indian Ocean Marine Research Centre University of Western Australia Crawley WA Australia
| | - Sabrina Fossette
- Marine Science Program, Biodiversity and Conservation Science Department of Biodiversity, Conservation and Attractions Kensington WA Australia
| | - Phillipa Wilson
- Australian Institute of Marine Science Indian Ocean Marine Research Centre University of Western Australia Crawley WA Australia
| | - Takahiro Shimada
- Australian Institute of Marine Science Indian Ocean Marine Research Centre University of Western Australia Crawley WA Australia
| | - Anton D. Tucker
- Marine Science Program, Biodiversity and Conservation Science Department of Biodiversity, Conservation and Attractions Kensington WA Australia
| | | | | | | | - Graham Loewenthal
- Remote Sensing and Spatial Analysis Program, Biodiversity and Conservation Science Department of Biodiversity, Conservation and Attractions Kensington WA Australia
| | - Joanne King
- Department of Biodiversity, Conservation and Attractions Parks and Wildlife Service Karratha WA Australia
| | - Marissa Speirs
- Marine Science Program, Biodiversity and Conservation Science Department of Biodiversity, Conservation and Attractions Kensington WA Australia
| | - Dani Rob
- Marine Science Program, Biodiversity and Conservation Science Department of Biodiversity, Conservation and Attractions Kensington WA Australia
| | - Scott D. Whiting
- Marine Science Program, Biodiversity and Conservation Science Department of Biodiversity, Conservation and Attractions Kensington WA Australia
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16
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Bestley S, Ropert-Coudert Y, Bengtson Nash S, Brooks CM, Cotté C, Dewar M, Friedlaender AS, Jackson JA, Labrousse S, Lowther AD, McMahon CR, Phillips RA, Pistorius P, Puskic PS, Reis AODA, Reisinger RR, Santos M, Tarszisz E, Tixier P, Trathan PN, Wege M, Wienecke B. Marine Ecosystem Assessment for the Southern Ocean: Birds and Marine Mammals in a Changing Climate. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.566936] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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17
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Photopoulou T, Heerah K, Pohle J, Boehme L. Sex-specific variation in the use of vertical habitat by a resident Antarctic top predator. Proc Biol Sci 2020; 287:20201447. [PMID: 33081623 PMCID: PMC7661299 DOI: 10.1098/rspb.2020.1447] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Patterns of habitat use are commonly studied in horizontal space, but this does not capture the four-dimensional nature of ocean habitats (space, depth, and time). Deep-diving marine animals encounter varying oceanographic conditions, particularly at the poles, where there is strong seasonal variation in vertical ocean structuring. This dimension of space use is hidden if we only consider horizontal movement. To identify different diving behaviours and usage patterns of vertically distributed habitat, we use hidden Markov models fitted to telemetry data from an air-breathing top predator, the Weddell seal, in the Weddell Sea, Antarctica. We present evidence of overlapping use of high-density, continental shelf water masses by both sexes, as well as important differences in their preferences for oceanographic conditions. Males spend more time in the unique high-salinity shelf water masses found at depth, while females also venture off the continental shelf and visit warmer, shallower water masses. Both sexes exhibit a diurnal pattern in diving behaviour (deep in the day, shallow at night) that persists from austral autumn into winter. The differences in habitat use in this resident, sexually monomorphic Antarctic top predator suggest a different set of needs and constraints operating at the intraspecific level, not driven by body size.
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Affiliation(s)
- Theoni Photopoulou
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK.,Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, UK
| | - Karine Heerah
- Marine Bioacoustics Lab, Zoophysiology, Dept. Biology, Aarhus University, Aarhus, Denmark
| | - Jennifer Pohle
- Department of Business Administration and Economics, Bielefeld University, Bielefeld, Germany
| | - Lars Boehme
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, UK
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18
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Environmental influences on foraging effort, success and efficiency in female Australian fur seals. Sci Rep 2020; 10:17710. [PMID: 33077806 PMCID: PMC7572486 DOI: 10.1038/s41598-020-73579-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 09/16/2020] [Indexed: 11/08/2022] Open
Abstract
Understanding the factors which influence foraging behaviour and success in marine mammals is crucial to predicting how their populations may respond to environmental change. The Australian fur seal (Arctocephalus pusillus doriferus, AUFS) is a predominantly benthic forager on the shallow continental shelf of Bass Strait, and represents the greatest biomass of marine predators in south-eastern Australia. The south-east Australian region is experiencing rapid oceanic warming, predicted to lead to substantial alterations in prey diversity, distribution and abundance. In the present study, foraging effort and indices of foraging success and efficiency were investigated in 138 adult female AUFS (970 foraging trips) during the winters of 1998–2019. Large scale climate conditions had a strong influence on foraging effort, foraging success and efficiency. Foraging effort and foraging success were also strongly influenced by winter chlorophyll-a concentrations and sea-surface height anomalies in Bass Strait. The results suggest increasing foraging effort and decreasing foraging success and efficiency under anticipated environmental conditions, which may have population-level impacts.
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19
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Henderson AF, McMahon CR, Harcourt R, Guinet C, Picard B, Wotherspoon S, Hindell MA. Inferring Variation in Southern Elephant Seal At-Sea Mortality by Modelling Tag Failure. FRONTIERS IN MARINE SCIENCE 2020; 7. [PMID: 0 DOI: 10.3389/fmars.2020.517901] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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20
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Breeding Colony Dynamics of Southern Elephant Seals at Patelnia Point, King George Island, Antarctica. REMOTE SENSING 2020. [DOI: 10.3390/rs12182964] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
During the 2019 breeding season (October-December), a battery-powered DIJ Inspire 2 drone was used to investigate a breeding southern elephant seal colony located at Patelnia Point (ASPA 128, King George Island, South Shetland Islands, maritime Antarctica). Twelve unmanned aerial vehicle (UAV) missions conducted 50–70 m above ground level (AGL) were completed to monitor the breeding ground with a maximum of 0.348 km2. The missions were planned in Pix4D Capture software. A drone, with the support of ground cameras and observations, was used to derive population counts, map harems, and track the phenology of the southern elephant seals. Based on data obtained from the UAV missions, orthophotomaps were created in PIX4D Mapper and then analyzed in QGIS. Calculated values of body size parameters such as body length and orthogonal body surface area were used to determine the age and sex of individuals. Analysis of the ranges of the harems on particular days, supported by an analysis of land conditions that generate physical barriers to the movement of animals, allowed zones in which the transformations of groups of harems took place to be determined. The hypothesized hermeticity of the designated zones was supported by statistical tests. The use of drones allows for comprehensive population analyses of the breeding colonies of elephant seals such as censuses of pups and adult individuals, determination of the sex ratio, and spatial analysis of the distribution of breeding formations. In addition, it allows for a more accurate result than ground counting.
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21
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Valenzuela-Toro AM, Zicos MH, Pyenson ND. Extreme dispersal or human-transport? The enigmatic case of an extralimital freshwater occurrence of a Southern elephant seal from Indiana. PeerJ 2020; 8:e9665. [PMID: 32953258 PMCID: PMC7474520 DOI: 10.7717/peerj.9665] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 07/15/2020] [Indexed: 11/20/2022] Open
Abstract
Elephant seals (Mirounga spp.) are the largest living pinnipeds, and the spatial scales of their ecology, with dives over 1 km in depth and foraging trips over 10,000 km long, are unrivalled by their near relatives. Here we report the discovery of an incomplete Holocene age Southern elephant seal (M. leonina) rostrum from Indiana, USA. The surviving material are two casts of the original specimen, which was collected in a construction excavation close to the Wabash River near Lafayette, Indiana. The original specimen was mostly destroyed for radiometric dating analyses in the 1970s, which resulted in an age of 1,260 ± 90 years before the present. The existence of sediments in the original specimen suggests some type of post depositional fluvial transportation. The prevalent evidence suggests that this male Southern elephant seal crossed the equator and the Gulf of Mexico, and then entered the Mississippi River system, stranding far upriver in Indiana or adjacent areas, similar to other reported examples of lost marine mammals in freshwater systems. Based on potential cut marks, we cannot exclude human-mediated transportation or scavenging by Indigenous peoples as a contributing factor of this occurrence. The material reported here represents by far the northernmost occurrence of a Southern elephant seal in the Northern Hemisphere ever recorded. The unusual occurrence of a top marine predator >1,000 km from the closest marine effluent as a potential extreme case of dispersal emphasizes how marine invasions of freshwater systems have happened frequently through historical (and likely geological) time.
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Affiliation(s)
- Ana M Valenzuela-Toro
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, United States of America.,Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America
| | - Maria H Zicos
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.,Department of Earth Sciences, Natural History Museum, London, United Kingdom
| | - Nicholas D Pyenson
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC, United States of America.,Department of Paleontology and Geology, Burke Museum of Natural History and Culture, Seattle, WA, United States of America
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22
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Mestre J, Authier M, Cherel Y, Harcourt R, McMahon CR, Hindell MA, Charrassin JB, Guinet C. Decadal changes in blood δ 13C values, at-sea distribution, and weaning mass of southern elephant seals from Kerguelen Islands. Proc Biol Sci 2020; 287:20201544. [PMID: 32811318 PMCID: PMC7482287 DOI: 10.1098/rspb.2020.1544] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/27/2020] [Indexed: 11/12/2022] Open
Abstract
Changes in the foraging environment and at-sea distribution of southern elephant seals from Kerguelen Islands were investigated over a decade (2004-2018) using tracking, weaning mass, and blood δ13C values. Females showed either a sub-Antarctic or an Antarctic foraging strategy, and no significant shift in their at-sea distribution was detected between 2004 and 2017. The proportion of females foraging in sub-Antarctic versus Antarctic habitats did not change over the 2006-2018 period. Pup weaning mass varied according to the foraging habitat of their mothers. The weaning mass of sub-Antarctic foraging mothers' pups decreased by 11.7 kg over the study period, but they were on average 5.8 kg heavier than pups from Antarctic foraging mothers. Pup blood δ13C values decreased by 1.1‰ over the study period regardless of their sex and the presumed foraging habitat of their mothers. Together, these results suggest an ecological change is occurring within the Indian sector of the Southern Ocean with possible consequences on the foraging performance of southern elephant seals. We hypothesize that this shift in δ13C is related to a change in primary production and/or in the composition of phytoplankton communities, but this requires further multidisciplinary investigations.
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Affiliation(s)
- Julie Mestre
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
- Sorbonne Université, Collège Doctoral, F-75005 Paris, France
| | - Matthieu Authier
- Observatoire PELAGIS, UMS 3462 La Rochelle Université and CNRS, La Rochelle, France
- ADERA, Pessac Cedex, France
| | - Yves Cherel
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Rob Harcourt
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Clive R. McMahon
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
- IMOS Animal Tagging, Sydney Institute of Marine Science, Sydney, NSW, Australia
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Mark A. Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | | | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
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23
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Stoffel MA, Acevedo-Whitehouse K, Morales-Durán N, Grosser S, Chakarov N, Krüger O, Nichols HJ, Elorriaga-Verplancken FR, Hoffman JI. Early sexual dimorphism in the developing gut microbiome of northern elephant seals. Mol Ecol 2020; 29:2109-2122. [PMID: 32060961 DOI: 10.1111/mec.15385] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/07/2020] [Accepted: 02/10/2020] [Indexed: 12/13/2022]
Abstract
The gut microbiome is an integral part of a species' ecology, but we know little about how host characteristics impact its development in wild populations. Here, we explored the role of such intrinsic factors in shaping the gut microbiome of northern elephant seals (Mirounga angustirostris) during a critical developmental window of 6 weeks after weaning, when the pups stay ashore without feeding. We found substantial sex differences in the early-life gut microbiome, even though males and females could not yet be distinguished morphologically. Sex and age both explained around 15% of the variation in gut microbial beta diversity, while microbial communities sampled from the same individual showed high levels of similarity across time, explaining another 40% of the variation. Only a small proportion of the variation in beta diversity was explained by health status, assessed by full blood counts, but clinically healthy individuals had a greater microbial alpha diversity than their clinically abnormal peers. Across the post-weaning period, the northern elephant seal gut microbiome was highly dynamic. We found evidence for several colonization and extinction events as well as a decline in Bacteroides and an increase in Prevotella, a pattern that has previously been associated with the transition from nursing to solid food. Lastly, we show that genetic relatedness was correlated with gut microbiome similarity in males but not females, again reflecting early sex differences. Our study represents a naturally diet-controlled and longitudinal investigation of how intrinsic factors shape the early gut microbiome in a species with extreme sex differences in morphology and life history.
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Affiliation(s)
- Martin A Stoffel
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany.,School of Natural Sciences and Psychology, Faculty of Science, Liverpool John Moores University, Liverpool, UK.,Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, UK
| | - Karina Acevedo-Whitehouse
- Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, Queretaro, México.,The Marine Mammal Center, Sausalito, CA, USA
| | - Nami Morales-Durán
- Unit for Basic and Applied Microbiology, School of Natural Sciences, Autonomous University of Queretaro, Queretaro, México
| | - Stefanie Grosser
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany
| | - Nayden Chakarov
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany
| | - Oliver Krüger
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany
| | - Hazel J Nichols
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany.,Department of Biosciences, College of Science, Swansea University, Swansea, UK
| | - Fernando R Elorriaga-Verplancken
- Departamento de Pesquerías y Biología Marina, Centro Interdisciplinario de Ciencias Marinas (CICIMAR-IPN), Instituto Politécnico Nacional, La Paz, Mexico
| | - Joseph I Hoffman
- Department of Animal Behaviour, Bielefeld University, Bielefeld, Germany.,British Antarctic Survey, Cambridge, UK
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24
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Cox SL, Authier M, Orgeret F, Weimerskirch H, Guinet C. High mortality rates in a juvenile free-ranging marine predator and links to dive and forage ability. Ecol Evol 2020; 10:410-430. [PMID: 31988734 PMCID: PMC6972805 DOI: 10.1002/ece3.5905] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 09/30/2019] [Accepted: 11/03/2019] [Indexed: 12/04/2022] Open
Abstract
High juvenile mortality rates are typical of many long-lived marine vertebrate predators. Insufficient development in dive and forage ability is considered a key driver of this. However, direct links to survival outcome are sparse, particularly in free-ranging marine animals that may not return to land.In this study, we conduct exploratory investigations toward early mortality in juvenile southern elephant seals Mirounga leonina. Twenty postweaning pups were equipped with (a) a new-generation satellite relay data tag, capable of remotely transmitting fine-scale behavioral movements from accelerometers, and (b) a location transmitting only tag (so that mortality events could be distinguished from device failures). Individuals were followed during their first trip at sea (until mortality or return to land). Two analyses were conducted. First, the behavioral movements and encountered environmental conditions of nonsurviving pups were individually compared to temporally concurrent observations from grouped survivors. Second, common causes of mortality were investigated using Cox's proportional hazard regression and penalized shrinkage techniques.Nine individuals died (two females and seven males) and 11 survived (eight females and three males). All but one individual died before the return phase of their first trip at sea, and all but one were negatively buoyant. Causes of death were variable, although common factors included increased horizontal travel speeds and distances, decreased development in dive and forage ability, and habitat type visited (lower sea surface temperatures and decreased total [eddy] kinetic energy).For long-lived marine vertebrate predators, such as the southern elephant seal, the first few months of life following independence represent a critical period, when small deviations in behavior from the norm appear sufficient to increase mortality risk. Survival rates may subsequently be particularly vulnerable to changes in climate and environment, which will have concomitant consequences on the demography and dynamics of populations.
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Affiliation(s)
- Sam L. Cox
- Centre d'Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Universitié de La RochelleVilliers‐en‐BoisFrance
- UMR MARBECStation Ifremer SéteSéteFrance
- Centre National d'Études Spatiales (CNES)ToulouseFrance
| | - Matthieu Authier
- Observatoire PELAGISUMS 3462 ‐ Universitié de La Rochelle & CNRSLa RochelleFrance
- ADERAPessac CedexFrance
| | - Florian Orgeret
- Centre d'Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Universitié de La RochelleVilliers‐en‐BoisFrance
| | - Henri Weimerskirch
- Centre d'Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Universitié de La RochelleVilliers‐en‐BoisFrance
| | - Christophe Guinet
- Centre d'Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Universitié de La RochelleVilliers‐en‐BoisFrance
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25
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Abstract
Mesopelagic fish and squid occupy ocean depths extending below the photic zone and their vertical migrations represent a massive pathway moving energy and carbon through the water column. Their spatio-temporal distribution is however, difficult to map across remote regions particularly the vast Southern Ocean. This represents a key gap in understanding biogeochemical processes, marine ecosystem structure, and how changing ocean conditions will affect marine predators, which depend upon mesopelagic prey. We infer mesopelagic prey vertical distribution and relative abundance in the Indian sector of the Southern Ocean (20° to 130°E) with a novel approach using predator-derived indices. Fourteen years of southern elephant seal tracking and dive data, from the open ocean between the Antarctic Polar Front and the southern Antarctic Circumpolar Current front, clearly show that the vertical distribution of mesopelagic prey is influenced by the physical hydrographic processes that structure their habitat. Mesopelagic prey have a more restricted vertical migration and higher relative abundance closer to the surface where Circumpolar Deep Water rises to shallower depths. Combining these observations with a future projection of Southern Ocean conditions we show that changes in the coupling of surface and deep waters will potentially redistribute mesopelagic prey. These changes are small overall, but show important spatial variability: prey will increase in relative abundance to the east of the Kerguelen Plateau but decrease to the west. The consequences for deep-diving specialists such as elephant seals and whales over this time scale will likely be minor, but the changes in mesoscale vertical energy flow have implications for predators that forage within the mesopelagic zone as well as the broader pelagic ecosystem.
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26
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Le Boeuf B, Condit R, Reiter J. Lifetime reproductive success of northern elephant seals (Mirounga angustirostris). CAN J ZOOL 2019. [DOI: 10.1139/cjz-2019-0104] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lifetime reproductive success of individuals in a natural population provides an estimate of Darwinian fitness. We calculated lifetime reproductive success in a colony of female northern elephant seals (Mirounga angustirostris (Gill, 1866)) by monitoring annual breeding throughout life of 7735 female weanlings marked individually at Año Nuevo, California, USA, from 1963 to 2005. Great variation in lifetime reproductive success was evident in three aspects of life history: (1) 75% of the females died before reaching breeding age and produced no pups; (2) nearly half of the survivors bred for only a few years before dying, and young females had low weaning success; (3) less than 1% of the females in the sample were exceptionally successful producing up to 20 pups in life. Many females that bred early, while still growing, had decreased lifespan, low weaning success, and lower lifetime reproductive success than females that postponed first breeding. Exceptional reproductive success was associated with giving birth annually, living long (up to age 23), and weaning large pups that were more likely to survive and breed. We conclude that there is strong selection for increased lifespan and multiparous supermoms that contribute significantly to pup production in the next generation.
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Affiliation(s)
- Burney Le Boeuf
- Department of Ecology and Evolutionary Biology and Long Marine Laboratory, 130 McAllister Way, University of California at Santa Cruz, Santa Cruz, CA 95060, USA
| | - Richard Condit
- Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605, USA
- Morton Arboretum, 4100 Illinois Route 53, Lisle, IL 60532, USA
| | - Joanne Reiter
- Institute for Marine Sciences, Long Marine Laboratory, 115 McAllister Way, University of California Santa Cruz, Santa Cruz, CA 95060, USA
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27
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Sequeira AMM, Heupel MR, Lea MA, Eguíluz VM, Duarte CM, Meekan MG, Thums M, Calich HJ, Carmichael RH, Costa DP, Ferreira LC, Fernandéz-Gracia J, Harcourt R, Harrison AL, Jonsen I, McMahon CR, Sims DW, Wilson RP, Hays GC. The importance of sample size in marine megafauna tagging studies. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2019; 29:e01947. [PMID: 31183944 DOI: 10.1002/eap.1947] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 04/10/2019] [Accepted: 04/17/2019] [Indexed: 06/09/2023]
Abstract
Telemetry is a key, widely used tool to understand marine megafauna distribution, habitat use, behavior, and physiology; however, a critical question remains: "How many animals should be tracked to acquire meaningful data sets?" This question has wide-ranging implications including considerations of statistical power, animal ethics, logistics, and cost. While power analyses can inform sample sizes needed for statistical significance, they require some initial data inputs that are often unavailable. To inform the planning of telemetry and biologging studies of marine megafauna where few or no data are available or where resources are limited, we reviewed the types of information that have been obtained in previously published studies using different sample sizes. We considered sample sizes from one to >100 individuals and synthesized empirical findings, detailing the information that can be gathered with increasing sample sizes. We complement this review with simulations, using real data, to show the impact of sample size when trying to address various research questions in movement ecology of marine megafauna. We also highlight the value of collaborative, synthetic studies to enhance sample sizes and broaden the range, scale, and scope of questions that can be answered.
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Affiliation(s)
- A M M Sequeira
- IOMRC and The University of Western Australia Oceans Institute, School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - M R Heupel
- Australian Institute of Marine Science, PMB No 3, Townsville, Queensland, 4810, Australia
| | - M-A Lea
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Hobart, Tasmania, 7000, Australia
| | - V M Eguíluz
- Instituto de Física Interdisciplinar y Sistemas Complejos IFISC (CSIC - UIB), E-07122, Palma de Mallorca, Spain
| | - C M Duarte
- Red Sea Research Centre (RSRC), King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - M G Meekan
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre (M096), University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009 Australia
| | - M Thums
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre (M096), University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009 Australia
| | - H J Calich
- IOMRC and The University of Western Australia Oceans Institute, Oceans Graduate School, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009, Australia
| | - R H Carmichael
- Dauphin Island Sea Lab and, University of South Alabama, 101 Bienville Boulevard, Dauphin Island, Alabama, 36528, USA
| | - D P Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, California, 95060, USA
| | - L C Ferreira
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre (M096), University of Western Australia, 35 Stirling Highway, Crawley, Western Australia, 6009 Australia
| | - J Fernandéz-Gracia
- Instituto de Física Interdisciplinar y Sistemas Complejos IFISC (CSIC - UIB), E-07122, Palma de Mallorca, Spain
| | - R Harcourt
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - A-L Harrison
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, PO Box 37012 MRC 5503 MBC, Washington, D.C., 20013, USA
| | - I Jonsen
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - C R McMahon
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
- Sydney Institute of Marine Science, 19 Chowder Bay Road, Mosman, 2088, New South Wales, Australia
| | - D W Sims
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, PL1 2PB, United Kingdom
- Ocean and Earth Science, National Oceanography Centre Southampton, Waterfront Campus, University of Southampton, Southampton, SO14 3ZH, United Kingdom
| | - R P Wilson
- Department of Biosciences, Swansea University, Swansea, United Kingdom
| | - G C Hays
- Deakin University, Geelong, Victoria, Australia
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Fearnbach H, Durban JW, Ellifrit DK, Pitman RL. Abundance of Type A killer whales (Orcinus orca) in the coastal waters off the western Antarctic Peninsula. Polar Biol 2019. [DOI: 10.1007/s00300-019-02534-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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29
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A quantitative, hierarchical approach for detecting drift dives and tracking buoyancy changes in southern elephant seals. Sci Rep 2019; 9:8936. [PMID: 31222003 PMCID: PMC6586652 DOI: 10.1038/s41598-019-44970-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 05/29/2019] [Indexed: 11/08/2022] Open
Abstract
Foraging behaviour of marine predators inferred from the analysis of horizontal or vertical movements commonly lack quantitative information about foraging success. Several marine mammal species are known to perform dives where they passively drift in the water column, termed “drift” dives. The drift rate is determined by the animal’s buoyancy, which can be used to make inference regarding body condition. Long term dive records retrieved via satellite uplink are often summarized before transmission. This loss of resolution hampers identification of drift dives. Here, we develop a flexible, hierarchically structured approach to identify drift dives and estimate the drift rate from the summarized time-depth profiles that are increasingly available to the global research community. Based on high-resolution dive data from southern elephant seals, we classify dives as drift/non-drift and apply a summarization algorithm. We then (i) automatically generate dive groups based on inflection point ordering using a ‘Reverse’ Broken-Stick Algorithm, (ii) develop a set of threshold criteria to apply across groups, ensuring non-drift dives are most efficiently rejected, and (iii) finally implement a custom Kalman filter to retain the remaining dives that are within the seals estimated drifting time series. Validation with independent data sets shows our method retains approximately 3% of all dives, of which 88% are true drift dives. The drift rate estimates are unbiased, with the upper 95% quantile of the mean squared error between the daily averaged summarized profiles using our method (SDDR) and the observed daily averaged drift rate (ODDR) being only 0.0015. The trend of the drifting time-series match expectations for capital breeders, showing the lowest body condition commencing foraging trips and a progressive improvement as they remain at sea. Our method offers sufficient resolution to track small changes in body condition at a fine temporal scale. This approach overcomes a long-term challenge for large existing and ongoing data collections, with potential application across other drift diving species. Enabling robust identification of foraging success at sea offers a rare and valuable opportunity for monitoring marine ecosystem productivity in space and time by tracking the success of a top predator.
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30
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Siegelman L, O'Toole M, Flexas M, Rivière P, Klein P. Submesoscale ocean fronts act as biological hotspot for southern elephant seal. Sci Rep 2019; 9:5588. [PMID: 30944405 PMCID: PMC6447572 DOI: 10.1038/s41598-019-42117-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 03/25/2019] [Indexed: 01/22/2023] Open
Abstract
The area west of the Kerguelen Islands (20-70°E/45-60°S) is characterized by a weak mesoscale activity except for a standing meander region of the Antarctic Circumpolar Current (ACC) localized between 20 and 40°E. A unique bio-physical dataset at high-resolution collected by a southern elephant seal (Mirounga leonina) reveals a conspicuous increase in foraging activity at the standing meander site up to 5 times larger than during the rest of her three-month trip west of the Kerguelen Islands. Here, we propose a physical explanation for such high biological activity based on the study of small-scale fronts with scales of 5 to 20 km, also called submesoscales. The standing meander is associated with intensified frontal dynamics at submesoscale, not observed in the rest of the region. Results shed new light on the spatial distribution of submesoscale fronts in the under-sampled area west of the Kerguelen plateau and emphasize their importance for upper trophic levels. Despite that most elephant seals target foraging grounds east of the Kerguelen Plateau, our findings suggest that excursions to the west are not accidental, and may be explained by the recurrently elevated physical and biological activity of the site. As such, other standing meanders of the ACC may also act as biological hotspots where trophic interactions are stimulated by submesoscale turbulence.
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Affiliation(s)
- Lia Siegelman
- Univ. Brest, CNRS, IRD, Ifremer, LEMAR, Plouzané, France. .,California Institute of Technology, Pasadena, CA, USA. .,Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA.
| | - Malcolm O'Toole
- UWA Oceans Institute, Indian Ocean Marine Research Centre, University of Western Australia, Crawley, WA, 6009, Australia
| | - Mar Flexas
- California Institute of Technology, Pasadena, CA, USA
| | - Pascal Rivière
- Univ. Brest, CNRS, IRD, Ifremer, LEMAR, Plouzané, France
| | - Patrice Klein
- California Institute of Technology, Pasadena, CA, USA.,Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
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31
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Hückstädt LA, Holser RR, Tift MS, Costa DP. The extra burden of motherhood: reduced dive duration associated with pregnancy status in a deep-diving mammal, the northern elephant seal. Biol Lett 2018; 14:rsbl.2017.0722. [PMID: 29445044 DOI: 10.1098/rsbl.2017.0722] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 01/02/2018] [Indexed: 11/12/2022] Open
Abstract
The cost of pregnancy is hard to study in marine mammals, particularly in species that undergo pregnancy while diving continuously at sea such as elephant seals (genus Mirounga). We analysed the diving behaviour of confirmed pregnant and non-pregnant northern elephant seals (M. angustirostris, n = 172) and showed that after an initial continuous increase in dive duration, dives of pregnant females become shorter after week 17. The reasons for this reduction in dive duration remain unknown, but we hypothesize that increased fetal demand for oxygen could be the cause. Our findings reveal an opportunity to explore the use of biologging data to investigate pregnancy status of free-ranging marine mammals and factors that could affect pregnancy success.
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Affiliation(s)
- Luis A Hückstädt
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Rachel R Holser
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Michael S Tift
- Division of Physiology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
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Chambault P, de Thoisy B, Huguin M, Martin J, Bonola M, Etienne D, Gresser J, Hiélard G, Mailles J, Védie F, Barnerias C, Sutter E, Guillemot B, Dumont‐Dayot É, Régis S, Lecerf N, Lefebvre F, Frouin C, Aubert N, Guimera C, Bordes R, Thieulle L, Duru M, Bouaziz M, Pinson A, Flora F, Queneherve P, Woignier T, Allenou J, Cimiterra N, Benhalilou A, Murgale C, Maillet T, Rangon L, Chanteux N, Chanteur B, Béranger C, Le Maho Y, Petit O, Chevallier D. Connecting paths between juvenile and adult habitats in the Atlantic green turtle using genetics and satellite tracking. Ecol Evol 2018; 8:12790-12802. [PMID: 30619583 PMCID: PMC6308873 DOI: 10.1002/ece3.4708] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 10/16/2018] [Accepted: 10/24/2018] [Indexed: 11/11/2022] Open
Abstract
Although it is commonly assumed that female sea turtles always return to the beach they hatched, the pathways they use during the years preceding their first reproduction and their natal origins are most often unknown, as it is the case for juvenile green turtles found in Martinique waters in the Caribbean. Given the oceanic circulation of the Guiana current flowing toward Martinique and the presence of important nesting sites for this species in Suriname and French Guiana, we may assume that a large proportion of the juvenile green turtles found in Martinique are originating from the Suriname-French Guiana beaches. To confirm this hypothesis, we performed mixed stock analysis (MSA) on 40 green turtles sampled in Martinique Island and satellite tracked 31 juvenile green turtles tagged in Martinique to (a) assess their natal origin and (b) identify their destination. Our results from MSA confirm that these juveniles are descendant from females laying on several Caribbean and Atlantic beaches, mostly from Suriname and French Guiana, but also from more southern Brazilian beaches. These results were confirmed by the tracking data as the 10 turtles leaving Martinique headed across the Caribbean-Atlantic region in six different directions and 50% of these turtles reached the Brazilian foraging grounds used by the adult green turtles coming from French Guiana. One turtle left the French Guianan coast to perform the first transatlantic migration ever recorded in juvenile green turtles, swimming toward Guinea-Bissau, which is the most important nesting site for green turtles along the African coast. The extensive movements of the migrant turtles evidenced the crossing of international waters and more than 25 exclusive economic zones, reinforcing the need for an international cooperative network to ensure the conservation of future breeders in this endangered species.
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Affiliation(s)
| | | | | | - Jordan Martin
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Marc Bonola
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Denis Etienne
- DEAL Martinique, Pointe de JahamSchoelcher CedexFrance
| | - Julie Gresser
- DEAL Martinique, Pointe de JahamSchoelcher CedexFrance
| | | | | | - Fabien Védie
- DEAL Martinique, Pointe de JahamSchoelcher CedexFrance
| | | | | | - Blandine Guillemot
- Section BoisbertDélégation Inter Régionale Outre‐mer, Chemin de BoyerLamentinFrance
| | - Émilie Dumont‐Dayot
- Section BoisbertDélégation Inter Régionale Outre‐mer, Chemin de BoyerLamentinFrance
| | - Sidney Régis
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Nicolas Lecerf
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Fabien Lefebvre
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Cédric Frouin
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Nathalie Aubert
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | | | - Robinson Bordes
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Laurent Thieulle
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Matthieu Duru
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Myriam Bouaziz
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | | | - Frédéric Flora
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | | | - Thierry Woignier
- IRD Martinique‐CaraïbeLe Lamentin Cédex 2France
- CNRS, IRD, IMBEAix Marseille University, University AvignonMarseilleFrance
| | | | | | | | | | | | - Luc Rangon
- IRD Martinique‐CaraïbeLe Lamentin Cédex 2France
- CNRS, IRD, IMBEAix Marseille University, University AvignonMarseilleFrance
| | | | | | | | - Yvon Le Maho
- CNRS‐IPHC UMR 7178Université de StrasbourgStrasbourg Cedex 2France
| | - Odile Petit
- CNRSÉquipe d'Éthologie Cognitive et SocialeStrasbourgFrance
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Cárcamo D, Pizarro M, Orellana M, Muñoz L, Pavez G, Sepúlveda M, Durán LR, Oliva D. Are southern elephant seals re-invading mid-latitude grounds? New sightings and first birth records off the Chilean Coast. Polar Biol 2018. [DOI: 10.1007/s00300-018-2433-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Griffiths CA, Patterson TA, Blanchard JL, Righton DA, Wright SR, Pitchford JW, Blackwell PG. Scaling marine fish movement behavior from individuals to populations. Ecol Evol 2018; 8:7031-7043. [PMID: 30073065 PMCID: PMC6065275 DOI: 10.1002/ece3.4223] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 02/13/2018] [Accepted: 03/29/2018] [Indexed: 11/25/2022] Open
Abstract
Understanding how, where, and when animals move is a central problem in marine ecology and conservation. Key to improving our knowledge about what drives animal movement is the rising deployment of telemetry devices on a range of free-roaming species. An increasingly popular way of gaining meaningful inference from an animal's recorded movements is the application of hidden Markov models (HMMs), which allow for the identification of latent behavioral states in the movement paths of individuals. However, the use of HMMs to explore the population-level consequences of movement is often limited by model complexity and insufficient sample sizes. Here, we introduce an alternative approach to current practices and provide evidence of how the inclusion of prior information in model structure can simplify the application of HMMs to multiple animal movement paths with two clear benefits: (a) consistent state allocation and (b) increases in effective sample size. To demonstrate the utility of our approach, we apply HMMs and adapted HMMs to over 100 multivariate movement paths consisting of conditionally dependent daily horizontal and vertical movements in two species of demersal fish: Atlantic cod (Gadus morhua; n = 46) and European plaice (Pleuronectes platessa; n = 61). We identify latent states corresponding to two main underlying behaviors: resident and migrating. As our analysis considers a relatively large sample size and states are allocated consistently, we use collective model output to investigate state-dependent spatiotemporal trends at the individual and population levels. In particular, we show how both species shift their movement behaviors on a seasonal basis and demonstrate population space use patterns that are consistent with previous individual-level studies. Tagging studies are increasingly being used to inform stock assessment models, spatial management strategies, and monitoring of marine fish populations. Our approach provides a promising way of adding value to tagging studies because inferences about movement behavior can be gained from a larger proportion of datasets, making tagging studies more relevant to management and more cost-effective.
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Affiliation(s)
- Christopher A. Griffiths
- School of Mathematics and StatisticsUniversity of SheffieldSheffieldUK
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTASAustralia
- Centre for EnvironmentFisheries and Aquaculture ScienceLowestoft LaboratoryLowestoftUK
| | | | - Julia L. Blanchard
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTASAustralia
| | - David A. Righton
- Centre for EnvironmentFisheries and Aquaculture ScienceLowestoft LaboratoryLowestoftUK
| | - Serena R. Wright
- Centre for EnvironmentFisheries and Aquaculture ScienceLowestoft LaboratoryLowestoftUK
| | | | - Paul G. Blackwell
- School of Mathematics and StatisticsUniversity of SheffieldSheffieldUK
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35
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Goedegebuure M, Melbourne-Thomas J, Corney SP, McMahon CR, Hindell MA. Modelling southern elephant seals Mirounga leonina using an individual-based model coupled with a dynamic energy budget. PLoS One 2018; 13:e0194950. [PMID: 29596456 PMCID: PMC5875804 DOI: 10.1371/journal.pone.0194950] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/13/2018] [Indexed: 01/08/2023] Open
Abstract
Higher trophic-level species are an integral component of any marine ecosystem. Despite their importance, methods for representing these species in end-to-end ecosystem models often have limited representation of life histories, energetics and behaviour. We built an individual-based model coupled with a dynamic energy budget for female southern elephant seals Mirounga leonina to demonstrate a method for detailed representation of marine mammals. We aimed to develop a model which could i) simulate energy use and life histories, as well as breeding traits of southern elephant seals in an emergent manner, ii) project a stable population over time, and iii) have realistic population dynamics and structure based on emergent life history features (such as age at first breeding, lifespan, fecundity and (yearling) survival). We evaluated the model's ability to represent a stable population over long time periods (>10 generations), including the sensitivity of the emergent properties to variations in key parameters. Analyses indicated that the model is sensitive to changes in resource availability and energy requirements for the transition from pup to juvenile, and juvenile to adult stage. This was particularly the case for breeding success and yearling survival. This model is suitable for use as a standalone tool for investigating the impacts of changes to behaviour and population responses of southern elephant seals.
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Affiliation(s)
- Merel Goedegebuure
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7000 Australia
- Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7000 Australia
| | - Jessica Melbourne-Thomas
- Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7000 Australia
- Australian Antarctic Division, Channel Highway, Kingston Tasmania 7050 Australia
| | - Stuart P. Corney
- Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7000 Australia
| | - Clive R. McMahon
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7000 Australia
- Sydney Institute of Marine Science, 19 Chowder Bay Road, Mosman, New South Wales 2088, Australia
| | - Mark A. Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7000 Australia
- Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7000 Australia
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36
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Convergence of marine megafauna movement patterns in coastal and open oceans. Proc Natl Acad Sci U S A 2018; 115:3072-3077. [PMID: 29483242 DOI: 10.1073/pnas.1716137115] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals' movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyze a global dataset of ∼2.8 million locations from >2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared with more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal microhabitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise, and declining oxygen content.
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37
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Coastal polynyas: Winter oases for subadult southern elephant seals in East Antarctica. Sci Rep 2018; 8:3183. [PMID: 29453356 PMCID: PMC5816617 DOI: 10.1038/s41598-018-21388-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 02/02/2018] [Indexed: 11/24/2022] Open
Abstract
Antarctic coastal polynyas are regions of persistent open water and are thought to be key bio-physical features within the sea-ice zone. However, their use by the upper trophic levels of ecosystems remains unclear. A unique bio-physical dataset recorded by southern elephant seals reveals that East Antarctic polynyas are a key winter foraging habitat for male seals. During their post-moult trips from Isles Kerguelen to the Antarctic continental shelf, a total of 18 out of 23 seals visited 9 different polynyas, spending on average 25 ± 20% (up to 75%) of their total trip time inside polynyas. Changes in seal foraging and diving behaviours are observed inside polynyas as compared to outside polynyas. Two polynya usages by seals are observed for the inactive and active polynya phases, pointing to different seasonal peaks in prey abundance. During the active polynya phase, we link seal foraging behaviour to changes in the physical stability of the water-column, which likely impact the seasonal biological dynamics within polynyas.
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38
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Oosthuizen WC, Altwegg R, Nevoux M, Bester MN, de Bruyn PJN. Phenotypic selection and covariation in the life-history traits of elephant seals: heavier offspring gain a double selective advantage. OIKOS 2018. [DOI: 10.1111/oik.04998] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- W. Chris Oosthuizen
- Dept of Zoology and Entomology; Mammal Research Inst., Univ. of Pretoria; Private Bag X20 Hatfield, Pretoria 0028 South Africa
- Centre for Statistics in Ecology, Environment and Conservation, Dept of Statistical Sciences; Univ. of Cape Town; Rondebosch South Africa
| | - Res Altwegg
- Centre for Statistics in Ecology, Environment and Conservation, Dept of Statistical Sciences; Univ. of Cape Town; Rondebosch South Africa
- African Climate and Development Initiative; Univ. of Cape Town; Rondebosch South Africa
| | - Marie Nevoux
- Dept of Zoology and Entomology; Mammal Research Inst., Univ. of Pretoria; Private Bag X20 Hatfield, Pretoria 0028 South Africa
| | - M. N. Bester
- Dept of Zoology and Entomology; Mammal Research Inst., Univ. of Pretoria; Private Bag X20 Hatfield, Pretoria 0028 South Africa
- INRA; UMR 0985 Ecology and Health of Ecosystems; Rennes France
| | - P. J. Nico de Bruyn
- Dept of Zoology and Entomology; Mammal Research Inst., Univ. of Pretoria; Private Bag X20 Hatfield, Pretoria 0028 South Africa
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Hindell MA, Sumner M, Bestley S, Wotherspoon S, Harcourt RG, Lea MA, Alderman R, McMahon CR. Decadal changes in habitat characteristics influence population trajectories of southern elephant seals. GLOBAL CHANGE BIOLOGY 2017; 23:5136-5150. [PMID: 28590592 DOI: 10.1111/gcb.13776] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 04/30/2017] [Indexed: 06/07/2023]
Abstract
Understanding divergent biological responses to climate change is important for predicting ecosystem level consequences. We use species habitat models to predict the winter foraging habitats of female southern elephant seals and investigate how changes in environmental variables within these habitats may be related to observed decreases in the Macquarie Island population. There were three main groups of seals that specialized in different ocean realms (the sub-Antarctic, the Ross Sea and the Victoria Land Coast). The physical and climate attributes (e.g. wind strength, sea surface height, ocean current strength) varied amongst the realms and also displayed different temporal trends over the last two to four decades. Most notably, sea ice extent increased on average in the Victoria Land realm while it decreased overall in the Ross Sea realm. Using a species distribution model relating mean residence times (time spent in each 50 × 50 km grid cell) to 9 climate and physical co-variates, we developed spatial predictions of residence time to identify the core regions used by the seals across the Southern Ocean from 120°E to 120°W. Population size at Macquarie Island was negatively correlated with ice concentration within the core habitat of seals using the Victoria Land Coast and the Ross Sea. Sea ice extent and concentration is predicted to continue to change in the Southern Ocean, having unknown consequences for the biota of the region. The proportion of Macquarie Island females (40%) utilizing the relatively stable sub-Antarctic region, may buffer this population against longer-term regional changes in habitat quality, but the Macquarie Island population has persistently decreased (-1.45% per annum) over seven decades indicating that environmental changes in the Antarctic are acting on the remaining 60% of the population to impose a long-term population decline in a top Southern Ocean predator.
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Affiliation(s)
- Mark A Hindell
- Institute for Marine & Antarctic Studies, Hobart, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart, Australia
| | - Michael Sumner
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart, Australia
- Australian Antarctic Division, Kingston, Australia
| | - Sophie Bestley
- Institute for Marine & Antarctic Studies, Hobart, Australia
- Australian Antarctic Division, Kingston, Australia
| | - Simon Wotherspoon
- Institute for Marine & Antarctic Studies, Hobart, Australia
- Australian Antarctic Division, Kingston, Australia
| | - Robert G Harcourt
- Department of Biological Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, Australia
| | - Mary-Anne Lea
- Institute for Marine & Antarctic Studies, Hobart, Australia
| | - Rachael Alderman
- Department of Primary Industries, Parks, Water and Environment, Hobart, Australia
| | - Clive R McMahon
- Institute for Marine & Antarctic Studies, Hobart, Australia
- Sydney Institute of Marine Science, Mosman, Australia
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Desprez M, Gimenez O, McMahon CR, Hindell MA, Harcourt RG. Optimizing lifetime reproductive output: Intermittent breeding as a tactic for females in a long-lived, multiparous mammal. J Anim Ecol 2017; 87:199-211. [PMID: 29063588 DOI: 10.1111/1365-2656.12775] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 10/11/2017] [Indexed: 11/30/2022]
Abstract
In iteroparous species, intermittent breeding is an important life-history tactic that can greatly affect animal population growth and viability. Despite its importance, few studies have quantified the consequences of breeding pauses on lifetime reproductive output, principally because calculating lifetime reproductive output requires knowledge of each individual's entire reproductive history. This information is extremely difficult to obtain in wild populations. We applied novel statistical approaches that account for uncertainty in state assessment and individual heterogeneity to an 18-year capture-recapture dataset of 6,631 female southern elephant seals from Macquarie Island. We estimated survival and breeding probabilities, and investigated the consequences of intermittent breeding on lifetime reproductive output. We found consistent differences in females' demographic performance between two heterogeneity classes. In particular, breeding imbued a high cost on survival in the females from the heterogeneity class 2, assumed to be females of lower quality. Individual quality also appeared to play a major role in a female's decision to skip reproduction with females of poorer quality more likely to skip breeding events than females of higher quality. Skipping some breeding events allowed females from both heterogeneity classes to increase lifetime reproductive output over females that bred annually. However, females of lower quality produced less offspring over their lifetime. Intermittent breeding seems to be used by female southern elephant seals as a tactic to offset reproductive costs on survival and enhance lifetime reproductive output but remains unavoidable and driven by individual-specific constraints in some other females.
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Affiliation(s)
- Marine Desprez
- Marine Predator Research Group, Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Olivier Gimenez
- CEFE UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, Montpellier Cedex 5, France
| | | | - Mark A Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia
| | - Robert G Harcourt
- Marine Predator Research Group, Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
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Malpress V, Bestley S, Corney S, Welsford D, Labrousse S, Sumner M, Hindell M. Bio-physical characterisation of polynyas as a key foraging habitat for juvenile male southern elephant seals (Mirounga leonina) in Prydz Bay, East Antarctica. PLoS One 2017; 12:e0184536. [PMID: 28902905 PMCID: PMC5597224 DOI: 10.1371/journal.pone.0184536] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 08/25/2017] [Indexed: 11/30/2022] Open
Abstract
Antarctic coastal polynyas are persistent open water areas in the sea ice zone, and regions of high biological productivity thought to be important foraging habitat for marine predators. This study quantified southern elephant seal (Mirounga leonina) habitat use within and around the polynyas of the Prydz Bay region (63°E– 88°E) in East Antarctica, and examined the bio-physical characteristics structuring polynyas as foraging habitat. Output from a climatological regional ocean model was used to provide context for in situ temperature-salinity vertical profiles collected by tagged elephant seals and to characterise the physical properties structuring polynyas. Biological properties were explored using remotely-sensed surface chlorophyll (Chl-a) and, qualitatively, historical fish assemblage data. Spatially gridded residence time of seals was examined in relation to habitat characteristics using generalized additive mixed models. The results showed clear polynya usage during early autumn and increasingly concentrated usage during early winter. Bathymetry, Chl-a, surface net heat flux (representing polynya location), and bottom temperature were identified as significant bio-physical predictors of the spatio-temporal habitat usage. The findings from this study confirm that the most important marine habitats for juvenile male southern elephant seals within Prydz Bay region are polynyas. A hypothesis exists regarding the seasonal evolution of primary productivity, coupling from surface to subsurface productivity and supporting elevated rates of secondary production in the upper water column during summer-autumn. An advancement to this hypothesis is proposed here, whereby this bio-physical coupling is likely to extend throughout the water column as it becomes fully convected during autumn-winter, to also promote pelagic-benthic linkages important for benthic foraging within polynyas.
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Affiliation(s)
- Veda Malpress
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
- Antarctic Climate & Ecosystem Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
- * E-mail:
| | - Sophie Bestley
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
- Antarctic Climate & Ecosystem Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
- Australian Antarctic Division, Department of Environment, Kingston, Tasmania, Australia
| | - Stuart Corney
- Antarctic Climate & Ecosystem Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
| | - Dirk Welsford
- Australian Antarctic Division, Department of Environment, Kingston, Tasmania, Australia
| | - Sara Labrousse
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
- Sorbonne Universités, UPMC University, Paris 06, UMR 7159 CNRS-IRD-MNHN, LOCEAN-IPSL, Paris, France
| | - Michael Sumner
- Antarctic Climate & Ecosystem Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
- Australian Antarctic Division, Department of Environment, Kingston, Tasmania, Australia
| | - Mark Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
- Antarctic Climate & Ecosystem Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
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Bras YL, Jouma’a J, Guinet C. Three-dimensional space use during the bottom phase of southern elephant seal dives. MOVEMENT ECOLOGY 2017; 5:18. [PMID: 28861272 PMCID: PMC5577837 DOI: 10.1186/s40462-017-0108-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 08/18/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND In marine pelagic ecosystems, the spatial distribution of biomass is heterogeneous and dynamic. At large scales, physical processes are the main driving forces of biomass distribution. At fine scales, both biotic and abiotic parameters are likely to be key determinants in the horizontal and vertical distribution of biomass, with direct consequences on the foraging behaviour of diving predators. However, fine scale three-dimensional (3D) spatial interactions between diving predators and their prey are still poorly known. RESULTS We reconstructed and examined the patterns of southern elephant seals 3D path during the bottom phase of their dives, and related them to estimated prey encounter density. We found that southern elephant seal tracks at bottom are strongly dominated by a single horizontal direction. In high prey density areas, seals travelled shorter distances but their track remained strongly orientated according to a main linear direction. Horizontal, and more importantly, vertical deviations from this main direction, were related negatively to the estimated prey density. We found that prey encounter density decreased with diving depth but tended to be more predictable. CONCLUSION Southern elephant seal behaviour during the bottom phase of their dives suggest that the prey are dispersed and distributed into layers in which their density relates to the vertical spread of the layer. The linear trajectories performed by the elephant seals would allow to explore the largest volume of water, maximizing the opportunities of prey encounter, while travelling great horizontal distances.
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Affiliation(s)
- Yves Le Bras
- Centre d’Études Biologiques de Chizé, UMR 7372, CNRS-ULR, Villiers-en-bois, 79360 France
| | - Joffrey Jouma’a
- Centre d’Études Biologiques de Chizé, UMR 7372, CNRS-ULR, Villiers-en-bois, 79360 France
| | - Christophe Guinet
- Centre d’Études Biologiques de Chizé, UMR 7372, CNRS-ULR, Villiers-en-bois, 79360 France
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43
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Michelot T, Langrock R, Bestley S, Jonsen ID, Photopoulou T, Patterson TA. Estimation and simulation of foraging trips in land-based marine predators. Ecology 2017; 98:1932-1944. [DOI: 10.1002/ecy.1880] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 04/18/2017] [Indexed: 01/31/2023]
Affiliation(s)
| | | | - Sophie Bestley
- Australian Antarctic Division; Department of Environment; Kingston Tasmania Australia
- Institute for Marine and Antarctic Studies; Hobart Tasmania Australia
| | - Ian D. Jonsen
- Macquarie University; Sydney New South Wales Australia
| | - Theoni Photopoulou
- Nelson Mandela Metropolitan University; Port Elizabeth South Africa
- University of Cape Town; Rondebosch South Africa
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44
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Multi-scale Modeling of Animal Movement and General Behavior Data Using Hidden Markov Models with Hierarchical Structures. JOURNAL OF AGRICULTURAL, BIOLOGICAL AND ENVIRONMENTAL STATISTICS 2017. [DOI: 10.1007/s13253-017-0282-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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45
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McIntyre T, Bester MN, Bornemann H, Tosh CA, de Bruyn PN. Slow to change? Individual fidelity to three-dimensional foraging habitats in southern elephant seals, Mirounga leonina. Anim Behav 2017. [DOI: 10.1016/j.anbehav.2017.03.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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46
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Clausius E, McMahon CR, Hindell MA. Five decades on: Use of historical weaning size data reveals that a decrease in maternal foraging success underpins the long-term decline in population of southern elephant seals (Mirounga leonina). PLoS One 2017; 12:e0173427. [PMID: 28301546 PMCID: PMC5354283 DOI: 10.1371/journal.pone.0173427] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 02/19/2017] [Indexed: 01/31/2023] Open
Abstract
The population of Southern elephant seals (Mirounga leonina) at Macquarie Island has declined since the 1960s, and is thought to be due to changing oceanic conditions leading to reductions in the foraging success of Macquarie Island breeding females. To test this hypothesis, we used a 55-year-old data set on weaning size of southern elephant seals to quantify a decrease in weaning size from a period of population stability in 1950s to its present state of on-going decline. Being capital breeders, the size of elephant seal pups at weaning is a direct consequence of maternal foraging success in the preceding year. During the 1940-1950s, the mean of female pups at weaning was similar between the Heard and Macquarie Island populations, while the snout-tail-length length of male weaners from Heard Island were longer than their conspecifics at Macquarie Island. Additionally, the snout-tail-length of pups at weaning decreased by 3cm between the 1950s and 1990s in the Macquarie Island population, concurrent with the observed population decline. Given the importance of weaning size in determining first-year survival and recruitment rates, the decline in the size at weaning suggests that the decline in the Macquarie Island population has, to some extent, been driven by reduced maternal foraging success, consequent declines in the size of pups at weaning, leading to reduced first-year survival rates and recruitment of breeding females into the population 3 to 4 years later.
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Affiliation(s)
- Ella Clausius
- Centre for Ecology and Biodiversity, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Clive R. McMahon
- Sydney Institute of Marine Science, Mosman, New South Wales, Australia
| | - Mark A. Hindell
- Centre for Ecology and Biodiversity, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart, Tasmania, Australia
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47
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Labrousse S, Sallée JB, Fraser AD, Massom RA, Reid P, Hobbs W, Guinet C, Harcourt R, McMahon C, Authier M, Bailleul F, Hindell MA, Charrassin JB. Variability in sea ice cover and climate elicit sex specific responses in an Antarctic predator. Sci Rep 2017; 7:43236. [PMID: 28233791 PMCID: PMC5324094 DOI: 10.1038/srep43236] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 01/20/2017] [Indexed: 11/09/2022] Open
Abstract
Contrasting regional changes in Southern Ocean sea ice have occurred over the last 30 years with distinct regional effects on ecosystem structure and function. Quantifying how Antarctic predators respond to such changes provides the context for predicting how climate variability/change will affect these assemblages into the future. Over an 11-year time-series, we examine how inter-annual variability in sea ice concentration and advance affect the foraging behaviour of a top Antarctic predator, the southern elephant seal. Females foraged longer in pack ice in years with greatest sea ice concentration and earliest sea ice advance, while males foraged longer in polynyas in years of lowest sea ice concentration. There was a positive relationship between near-surface meridional wind anomalies and female foraging effort, but not for males. This study reveals the complexities of foraging responses to climate forcing by a poleward migratory predator through varying sea ice property and dynamic anomalies.
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Affiliation(s)
- Sara Labrousse
- Sorbonne Universités, UPMC Univ., Paris 06, UMR 7159 CNRS-IRD-MNHN, LOCEAN-IPSL, 75005 Paris, France.,Marine Predator Unit, Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia
| | - Jean-Baptiste Sallée
- Sorbonne Universités, UPMC Univ., Paris 06, UMR 7159 CNRS-IRD-MNHN, LOCEAN-IPSL, 75005 Paris, France.,British Antarctic Survey, High Cross, Cambridge, CB3 0ET, UK
| | - Alexander D Fraser
- Institute of Low Temperature Science, Hokkaido University, N19 W8, Kita-ku, Sapporo 060-0819, Japan.,Antarctic Climate &Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia
| | - Rob A Massom
- Antarctic Climate &Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia.,Australian Antarctic Division, Channel Highway, Kingston, Tasmania 7050, Australia
| | - Phillip Reid
- Australian Bureau of Meteorology, Centre for Australian Weather and Climate Research, Hobart, Tasmania 7001, Australia
| | - William Hobbs
- Antarctic Climate &Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia.,Centre of Excellence for Climate System Science, Australian Research Council, Sydney, New South Wales 2052, Australia
| | - Christophe Guinet
- Centre d'Etudes Biologiques de Chizé (CEBC), UMR 7372 Université de la Rochelle-CNRS, 79360 Villiers en Bois, France
| | - Robert Harcourt
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Clive McMahon
- Marine Predator Unit, Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia.,Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia.,Sydney Institute of Marine Science, 19 Chowder Bay Road, Mosman, New South Wales 2088, Australia
| | - Matthieu Authier
- Observatoire PELAGIS, UMS 3462 CNRS-ULR, 17000 La Rochelle, France
| | - Frédéric Bailleul
- South Australian Research &Development Institute (SARDI), 2 Hamra Avenue, West Beach, South Australia 5024, Australia
| | - Mark A Hindell
- Marine Predator Unit, Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia.,Antarctic Climate &Ecosystems Cooperative Research Centre, University of Tasmania, Private Bag 80, Hobart, Tasmania 7001, Australia
| | - Jean-Benoit Charrassin
- Sorbonne Universités, UPMC Univ., Paris 06, UMR 7159 CNRS-IRD-MNHN, LOCEAN-IPSL, 75005 Paris, France
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48
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Heerah K, Hindell M, Andrew-Goff V, Field I, McMahon CR, Charrassin JB. Contrasting behavior between two populations of an ice-obligate predator in East Antarctica. Ecol Evol 2017; 7:606-618. [PMID: 28116057 PMCID: PMC5243189 DOI: 10.1002/ece3.2652] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 11/04/2016] [Accepted: 11/08/2016] [Indexed: 11/23/2022] Open
Abstract
The Austral autumn–winter is a critical period for capital breeders such as Weddell seals that must optimize resource acquisition and storage to provision breeding in the subsequent spring. However, how Weddell seals find food in the winter months remains poorly documented. We equipped adult Weddell seals after their annual molt with satellite‐relayed data loggers at two sites in East Antarctica: Dumont D'Urville (n = 12, DDU) and Davis (n = 20). We used binomial generalized mixed‐effect models to investigate Weddell seals’ behavioral response (i.e., “hunting” vs. “transit”) to physical aspects of their environment (e.g., ice concentration). Weddell seal foraging was concentrated to within 5 km of a breathing hole, and they appear to move between holes as local food is depleted. There were regional differences in behavior so that seals at Davis traveled greater distances (three times more) and spent less time in hunting mode (half the time) than seals at DDU. Despite these differences, hunting dives at both locations were pelagic, concentrated in areas of high ice concentration, and over areas of complex bathymetry. There was also a seasonal change in diving behavior from transiting early in the season to more hunting during winter. Our observations suggest that Weddell seal foraging behavior is plastic and that they respond behaviorally to changes in their environment to maximize food acquisition and storage. Such plasticity is a hallmark of animals that live in very dynamic environments such as the high Antarctic where resources are unpredictable.
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Affiliation(s)
- Karine Heerah
- LOCEAN Laboratory Sorbonne Universités (UPMC, Univ Paris 06)-CNRS-IRD-MNHN Paris France; Institute for Marine and Antarctic Studies University of Tasmania Hobart Tas. Australia
| | - Mark Hindell
- Institute for Marine and Antarctic Studies University of Tasmania Hobart Tas. Australia; Antarctic Climate and Ecosystem Cooperative Research Centre University of Tasmania Hobart Tas. Australia
| | - Virginia Andrew-Goff
- Institute for Marine and Antarctic Studies University of Tasmania Hobart Tas. Australia
| | - Iain Field
- Department of Biological Sciences Macquarie University Sydney NSW Australia
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McMahon CR, Harcourt RG, Burton HR, Daniel O, Hindell MA. Seal mothers expend more on offspring under favourable conditions and less when resources are limited. J Anim Ecol 2017; 86:359-370. [PMID: 27859273 DOI: 10.1111/1365-2656.12611] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 11/02/2016] [Indexed: 01/29/2023]
Abstract
In mammals, maternal expenditure on offspring is a complex mix of several factors including the species' mating system, offspring sex and the condition and age of the mother. While theory suggests that in polygynous species mothers should wean larger male offspring than females when resources and maternal conditions allow, the evidence for this remains equivocal. Southern elephant seals are highly dimorphic, polygynous capital breeders existing in an environment with highly variable resources and should therefore provide clear evidence to support the theoretical expectations of differential maternal expenditure in male and female pups. We quantified maternal size (mass and length) and pup size at birth and weaning for 342 elephant seal mothers at Macquarie Island. The study was conducted over 11 years of contrasting sea-ice and Southern Annular Mode values, both indices of maternal prey resources. Overall, large females weaned male pups that weighed 17 kg (15·5%) more than female pups. Maternal condition varied by as much as 59 kg among years, and was positively related to Southern Annular Mode, and negatively to maximum sea-ice extent. Smaller mothers weaned relatively larger male pups under favourable conditions, this effect was less apparent for larger mothers. We developed a simple model linking environmental variation to maternal masses post-partum, followed by maternal masses post-partum to weaning masses and then weaning masses to pup survival and demonstrated that environmental conditions affected predicted survival so that the pups of small mothers had an estimated 7% increase in first year survival in 'good' vs. 'bad' years compared to 1% for female pups of large mothers. Co-occurrence of environmental quality and conservative reproductive tactics suggests that mothers retain substantial plasticity in maternal care, enhancing their lifetime reproductive success by adjusting reproductive expenditure relative to both prevailing environmental conditions and their own capabilities.
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Affiliation(s)
- Clive R McMahon
- Sydney Institute of Marine Science, 19 Chowder Bay Road, Mosman, NSW, 2088, Australia.,Institute of Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, TAS, 7000, Australia.,Marine Predator Research Group, Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Robert G Harcourt
- Marine Predator Research Group, Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Harry R Burton
- Australian Antarctic Division, Channel Highway, Kingston, TAS, 7050, Australia
| | - Owen Daniel
- Institute of Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, TAS, 7000, Australia
| | - Mark A Hindell
- Institute of Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, TAS, 7000, Australia.,Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, TAS, 7000, Australia
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50
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McMahon CR, Thums M, Bradshaw M, Busby S, Chapple V, Evans M, Goodlich S, Holland C, Raudino H, Rebuck P, Hindell MA. It’s a girl! A female southern elephant seal born in Western Australia. AUST J ZOOL 2017. [DOI: 10.1071/zo17036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Southern elephant seals typically breed on subantarctic islands and breeding in more temperate regions is rare. This small female (~1.42 m) that weaned after 25 days is smaller than the average weaned female elephant seal and her survival prospects are correspondingly low (20–35%). The fact that the elephant seal was successfully weaned offers some insight into the breeding plasticity in this species.
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