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Waller MJ, Humphries NE, Womersley FC, Loveridge A, Jeffries AL, Watanabe Y, Payne N, Semmens J, Queiroz N, Southall EJ, Sims DW. The vulnerability of sharks, skates, and rays to ocean deoxygenation: Physiological mechanisms, behavioral responses, and ecological impacts. JOURNAL OF FISH BIOLOGY 2024. [PMID: 38852616 DOI: 10.1111/jfb.15830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 05/08/2024] [Accepted: 05/20/2024] [Indexed: 06/11/2024]
Abstract
Levels of dissolved oxygen in open ocean and coastal waters are decreasing (ocean deoxygenation), with poorly understood effects on marine megafauna. All of the more than 1000 species of elasmobranchs (sharks, skates, and rays) are obligate water breathers, with a variety of life-history strategies and oxygen requirements. This review demonstrates that although many elasmobranchs typically avoid hypoxic water, they also appear capable of withstanding mild to moderate hypoxia with changes in activity, ventilatory responses, alterations to circulatory and hematological parameters, and morphological alterations to gill structures. However, such strategies may be insufficient to withstand severe, progressive, or prolonged hypoxia or anoxia where anaerobic metabolic pathways may be used for limited periods. As water temperatures increase with climate warming, ectothermic elasmobranchs will exhibit elevated metabolic rates and are likely to be less able to tolerate the effects of even mild hypoxia associated with deoxygenation. As a result, sustained hypoxic conditions in warmer coastal or surface-pelagic waters are likely to lead to shifts in elasmobranch distributions. Mass mortalities of elasmobranchs linked directly to deoxygenation have only rarely been observed but are likely underreported. One key concern is how reductions in habitat volume as a result of expanding hypoxia resulting from deoxygenation will influence interactions between elasmobranchs and industrial fisheries. Catch per unit of effort of threatened pelagic sharks by longline fisheries, for instance, has been shown to be higher above oxygen minimum zones compared to adjacent, normoxic regions, and attributed to vertical habitat compression of sharks overlapping with increased fishing effort. How a compound stressor such as marine heatwaves alters vulnerability to deoxygenation remains an open question. With over a third of elasmobranch species listed as endangered, a priority for conservation and management now lies in understanding and mitigating ocean deoxygenation effects in addition to population declines already occurring from overfishing.
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Affiliation(s)
- Matt J Waller
- Marine Biological Association, The Laboratory, Plymouth, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
| | | | | | | | - Amy L Jeffries
- Marine Biological Association, The Laboratory, Plymouth, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
| | - Yuuki Watanabe
- Research Center for Integrative Evolutionary Science, The Graduate University for Advanced Studies, SOKENDAI, Kanagawa, Japan
| | - Nicholas Payne
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin, Ireland
| | - Jayson Semmens
- Institue for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Nuno Queiroz
- CIBIO/InBIO, Universidade do Porto, Vairão, Portugal
- BIOPOLIS, Program in Genomics, Biodiversity and Land Planning, CIBIO, Vairão, Portugal
| | | | - David W Sims
- Marine Biological Association, The Laboratory, Plymouth, UK
- Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, UK
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Ventura F, Granadeiro JP, Catry P, Gjerdrum C, De Pascalis F, Viveiros F, Silva I, Menezes D, Paiva VH, Silva MC. Allochrony is shaped by foraging niche segregation rather than adaptation to the windscape in long-ranging seabirds. MOVEMENT ECOLOGY 2024; 12:27. [PMID: 38566221 PMCID: PMC10988818 DOI: 10.1186/s40462-024-00463-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/26/2024] [Indexed: 04/04/2024]
Abstract
BACKGROUND Ecological segregation allows populations to reduce competition and coexist in sympatry. Using as model organisms two closely related gadfly petrels endemic to the Madeira archipelago and breeding with a two month allochrony, we investigated how movement and foraging preferences shape ecological segregation in sympatric species. We tested the hypothesis that the breeding allochrony is underpinned by foraging niche segregation. Additionally, we investigated whether our data supported the hypothesis that allochrony is driven by species-specific adaptations to different windscapes. METHODS We present contemporaneous tracking and stable isotopes datasets for Zino's (Pterodroma madeira) and Desertas (Pterodroma deserta) petrels. We quantified the year-round distribution of the petrels, characterised their isotopic niches and quantified their habitat preferences using machine learning (boosted regression trees). Hidden-Markov-models were used to investigate the effect of wind on the central-place movement speed, and a simulation framework was developed to investigate whether each species breeds at times when the windscape is most favourable to sustain their trips. RESULTS Despite substantial spatial overlap throughout the year, the petrels exhibited diverging isotopic niches and habitat preferences during breeding. Both species used a vast pelagic region in the North Atlantic, but targeted two different mesopelagic ecoregions and showed a preference for habitats mostly differing in sea surface temperature values. Based on our simulation framework, we found that both species would perform trips of similar speed during the other species' breeding season. CONCLUSIONS The different breeding schedules between the species are underpinned by differences in foraging habitat preferences and adaptation to the local environment, rather than to the windscape. Nevertheless, the larger Desertas petrels exploited significantly windier conditions, potentially unsustainable for the smaller Zino's petrels. Furthermore, due to larger mass and likely higher fasting endurance, Desertas petrels engaged in central-place-foraging movements that covered more ground and lasted longer than those of Zino's petrels. Ultimately, patterns of ecological segregation in sympatric seabirds are shaped by a complex interplay between foraging and movement ecology, where morphology, foraging trip regulation and fasting endurance have an important- yet poorly understood- role.
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Affiliation(s)
- Francesco Ventura
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
| | - José Pedro Granadeiro
- CESAM, Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisboa, Portugal
| | - Paulo Catry
- MARE - Marine and Environmental Sciences Centre / ARNET - Aquatic Research Network, Ispa - Instituto Universitário, Rua Jardim do Tabaco 34, 1149-041, Lisboa, Portugal
| | - Carina Gjerdrum
- Canadian Wildlife Service, Environment and Climate Change Canada, B2Y 2N6, Dartmouth, NS, Canada
| | - Federico De Pascalis
- Area Avifauna Migratrice, Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), Ozzano dell'Emilia, Italy
| | - Filipe Viveiros
- Parque Natural da Madeira, Quinta do Bom Sucesso, Caminho do Meio, 9050-251, Funchal, Madeira, Portugal
| | - Isamberto Silva
- Parque Natural da Madeira, Quinta do Bom Sucesso, Caminho do Meio, 9050-251, Funchal, Madeira, Portugal
| | - Dilia Menezes
- Parque Natural da Madeira, Quinta do Bom Sucesso, Caminho do Meio, 9050-251, Funchal, Madeira, Portugal
| | - Vítor H Paiva
- MARE - Marine and Environmental Sciences Centre / ARNET - Aquatic Research Network, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - Mónica C Silva
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Departamento de Biologia Animal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016, Lisboa, Portugal
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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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Costa DP, Favilla AB. Field physiology in the aquatic realm: ecological energetics and diving behavior provide context for elucidating patterns and deviations. J Exp Biol 2023; 226:jeb245832. [PMID: 37843467 DOI: 10.1242/jeb.245832] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023]
Abstract
Comparative physiology has developed a rich understanding of the physiological adaptations of organisms, from microbes to megafauna. Despite extreme differences in size and a diversity of habitats, general patterns are observed in their physiological adaptations. Yet, many organisms deviate from the general patterns, providing an opportunity to understand the importance of ecology in determining the evolution of unusual adaptations. Aquatic air-breathing vertebrates provide unique study systems in which the interplay between ecology, physiology and behavior is most evident. They must perform breath-hold dives to obtain food underwater, which imposes a physiological constraint on their foraging time as they must resurface to breathe. This separation of two critical resources has led researchers to investigate these organisms' physiological adaptations and trade-offs. Addressing such questions on large marine animals is best done in the field, given the difficulty of replicating the environment of these animals in the lab. This Review examines the long history of research on diving physiology and behavior. We show how innovative technology and the careful selection of research animals have provided a holistic understanding of diving mammals' physiology, behavior and ecology. We explore the role of the aerobic diving limit, body size, oxygen stores, prey distribution and metabolism. We then identify gaps in our knowledge and suggest areas for future research, pointing out how this research will help conserve these unique animals.
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Affiliation(s)
- Daniel P Costa
- Institute of Marine Sciences, Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95060, USA
| | - Arina B Favilla
- Institute of Marine Sciences, Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95060, USA
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5
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Holser RR, Crocker DE, Favilla AR, Adachi T, Keates TR, Naito Y, Costa DP. Effects of disease on foraging behaviour and success in an individual free-ranging northern elephant seal. CONSERVATION PHYSIOLOGY 2023; 11:coad034. [PMID: 37250476 PMCID: PMC10214463 DOI: 10.1093/conphys/coad034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 04/14/2023] [Accepted: 05/17/2023] [Indexed: 05/31/2023]
Abstract
Evaluating consequences of stressors on vital rates in marine mammals is of considerable interest to scientific and regulatory bodies. Many of these species face numerous anthropogenic and environmental disturbances. Despite its importance as a critical form of mortality, little is known about disease progression in air-breathing marine megafauna at sea. We examined the movement, diving, foraging behaviour and physiological state of an adult female northern elephant seal (Mirounga angustirostris) who suffered from an infection while at sea. Comparing her to healthy individuals, we identified abnormal behavioural patterns from high-resolution biologging instruments that are likely indicators of diseased and deteriorating condition. We observed continuous extended (3-30 minutes) surface intervals coinciding with almost no foraging attempts (jaw motion) during 2 weeks of acute illness early in her post-breeding foraging trip. Elephant seals typically spend ~ 2 minutes at the surface. There were less frequent but highly extended (30-200 minutes) surface periods across the remainder of the trip. Dive duration declined throughout the trip rather than increasing. This seal returned in the poorest body condition recorded for an adult female elephant seal (18.3% adipose tissue; post-breeding trip average is 30.4%). She was immunocompromised at the end of her foraging trip and has not been seen since that moulting season. The timing and severity of the illness, which began during the end of the energy-intensive lactation fast, forced this animal over a tipping point from which she could not recover. Additional physiological constraints to foraging, including thermoregulation and oxygen consumption, likely exacerbated her already poor condition. These findings improve our understanding of illness in free-ranging air-breathing marine megafauna, demonstrate the vulnerability of individuals at critical points in their life history, highlight the importance of considering individual health when interpreting biologging data and could help differentiate between malnutrition and other causes of at-sea mortality from transmitted data.
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Affiliation(s)
- Rachel R Holser
- Corresponding author: Institute of Marine Sciences, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA. Tel.: +1 253-514-0110.
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, California, 94928, USA
| | - Arina R Favilla
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, 95064 USA
| | - Taiki Adachi
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, 95064 USA
- National Institute of Polar Research, Tachikawa, Tokyo, Japan
| | - Theresa R Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, California, 95064, USA
| | - Yasuhiko Naito
- National Institute of Polar Research, Tachikawa, Tokyo, Japan
| | - Daniel P Costa
- Institute of Marine Sciences, University of California Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, California, 95064 USA
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Nati JJH, Halsey LG, Johnson PCD, Lindström J, Killen SS. Does aerobic scope influence geographical distribution of teleost fishes? CONSERVATION PHYSIOLOGY 2023; 11:coad012. [PMID: 37006338 PMCID: PMC10061159 DOI: 10.1093/conphys/coad012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/20/2023] [Accepted: 03/16/2023] [Indexed: 06/19/2023]
Abstract
Many abiotic and biotic factors are known to shape species' distributions, but we lack understanding of how innate physiological traits, such as aerobic scope (AS), may influence the latitudinal range of species. Based on theoretical assumptions, a positive link between AS and distribution range has been proposed, but there has been no broad comparative study across species to test this hypothesis. We collected metabolic rate data from the literature and performed a phylogenetically informed analysis to investigate the influence of AS on the current geographical distributions of 111 teleost fish species. Contrary to expectations, we found a negative relationship between absolute latitude range and thermal peak AS in temperate fishes. We found no evidence for an association between thermal range of AS and the range of latitudes occupied for 32 species. Our main results therefore contradict the prevailing theory of a positive link between AS and distribution range in fish.
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Affiliation(s)
- Julie J H Nati
- Corresponding author: School of Biodiversity, One Health and Veterinary, Graham Kerr Building, Glasgow G12 8QQ, UK.
| | - Lewis G Halsey
- Department of Life Sciences, University of Roehampton, Holybourne Avenue, London SW15 4JD, UK
| | - Paul C D Johnson
- School of Biodiversity, One Health and Veterinary, Graham Kerr Building, Glasgow G12 8QQ, UK
| | - Jan Lindström
- School of Biodiversity, One Health and Veterinary, Graham Kerr Building, Glasgow G12 8QQ, UK
| | - Shaun S Killen
- School of Biodiversity, One Health and Veterinary, Graham Kerr Building, Glasgow G12 8QQ, UK
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Watanabe YY, Papastamatiou YP. Biologging and Biotelemetry: Tools for Understanding the Lives and Environments of Marine Animals. Annu Rev Anim Biosci 2023; 11:247-267. [PMID: 36790885 DOI: 10.1146/annurev-animal-050322-073657] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Addressing important questions in animal ecology, physiology, and environmental science often requires in situ information from wild animals. This difficulty is being overcome by biologging and biotelemetry, or the use of miniaturized animal-borne sensors. Although early studies recorded only simple parameters of animal movement, advanced devices and analytical methods can now provide rich information on individual and group behavior, internal states, and the surrounding environment of free-ranging animals, especially those in marine systems. We summarize the history of technologies used to track marine animals. We then identify seven major research categories of marine biologging and biotelemetry and explain significant achievements, as well as future opportunities. Big data approaches via international collaborations will be key to tackling global environmental issues (e.g., climate change impacts), and curiosity about the secret lives of marine animals will also remain a major driver of biologging and biotelemetry studies.
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Affiliation(s)
- Yuuki Y Watanabe
- National Institute of Polar Research, Tachikawa, Tokyo, Japan; .,Department of Polar Science, The Graduate University for Advanced Studies, SOKENDAI, Tachikawa, Tokyo, Japan
| | - Yannis P Papastamatiou
- Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, Florida, USA
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8
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Lapsansky AB, Warrick DR, Tobalske BW. High Wing-Loading Correlates with Dive Performance in Birds, Suggesting a Strategy to Reduce Buoyancy. Integr Comp Biol 2022; 62:878-889. [PMID: 35810134 DOI: 10.1093/icb/icac117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/24/2022] [Accepted: 06/27/2022] [Indexed: 11/14/2022] Open
Abstract
Diving birds are regarded as a classic example of morphological convergence (Darwin 1859). Divers tend to have small wings extending from rotund bodies, requiring many volant species to fly with rapid wingbeats, and rendering others flightless (Darwin 1839; Simpson 1946). The high wing-loading of diving birds is frequently associated with the challenge of using forelimbs adapted for flight for locomotion in a "draggier" fluid, but this does not explain why species that rely exclusively on their feet to dive should have relatively small wings, as well. Therefore, others have hypothesized that ecological factors shared by wing-propelled and foot-propelled diving birds drive the evolution of high wing-loading. Following a reexamination of the aquatic habits of birds, we tested between hypotheses seeking to explain high wing-loading in divers using new comparative data and phylogenetically informed analyses. We found little evidence that wing-propelled diving selects for small wings, as wing-propelled and foot-propelled species share similar wing-loadings. Instead, our results suggest that selection to reduce buoyancy has driven high wing-loading in divers, offering insights for the development of bird-like aquatic robots.
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Affiliation(s)
- Anthony B Lapsansky
- Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, MT, USA.,Department of Zoology, University of British Columbia, BC, Canada
| | | | - Bret W Tobalske
- Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, MT, USA
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Gusztak RW, MacArthur RA, Campbell KL. Dive performance and aquatic thermoregulation of the world’s smallest mammalian diver, the American water shrew (Sorex palustris). Physiol Biochem Zool 2022; 95:438-463. [DOI: 10.1086/721186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Abstract
Albatrosses are the iconic aerial wanderers of the oceans, supremely adapted for long-distance dynamic soaring flight. Perhaps because of this they are considered poorly adapted for diving1, in contrast to many smaller shearwater and petrel relatives, despite having amphibious eyes2, and an a priori mass advantage for oxygen-storage tolerance3. Modern biologging studies have largely confirmed this view4,5, casting doubt on earlier observations using capillary tube maximum depth gauges1, which may exaggerate depths, and emphasising albatrosses' reliance on near-surface feeding. Nevertheless, uncertainty about albatross diving remains an important knowledge gap since bycatch in human fisheries (e.g. birds becoming hooked when diving for longline bait fish) is thought to be driving many population declines in this most threatened group of birds6. Here we show, using miniature electronic depth loggers (TDRs), that black-browed albatross, Thalassarche melanophris, can dive to much greater depths (19 m) and for much longer (52 s) than previously thought - three times the maxima previously recorded for this species (6 m and 15 s), and more than twice the maxima reliably recorded previously for any albatross (from 113.7 bird-days of tracking4,5,7). Further evidence that diving may be a significant behavioural adaptation in some albatrosses comes from co-deployed 3-axis accelerometers showing that these deeper dives, which occur in most individuals we tracked, involve active under-water propulsion without detectable initial assistance from momentum, sometimes with bottom phases typical of active prey pursuit. Furthermore, we find (from co-deployed GPS) that diving occurs primarily in the distal portions of long-distance foraging trips, with deeper dives occurring exclusively during daylight or civil twilight, confirming the importance of visual guidance.
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Affiliation(s)
- Tim Guilford
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford OX1 3SZ, UK.
| | - Oliver Padget
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford OX1 3SZ, UK.
| | - Louise Maurice
- British Geological Survey, Maclean Building, Crowmarsh Gifford, Wallingford OX10 8BB, UK
| | - Paulo Catry
- MARE - Marine and Environmental Sciences Center, ISPA - Instituto Universitário, Lisbon, Portugal
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Fromant A, Arnould JPY, Delord K, Sutton GJ, Carravieri A, Bustamante P, Miskelly CM, Kato A, Brault-Favrou M, Cherel Y, Bost CA. Stage-dependent niche segregation: insights from a multi-dimensional approach of two sympatric sibling seabirds. Oecologia 2022; 199:537-548. [PMID: 35606670 PMCID: PMC9309125 DOI: 10.1007/s00442-022-05181-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 04/30/2022] [Indexed: 01/05/2023]
Abstract
Niche theory predicts that to reduce competition for the same resource, sympatric ecologically similar species should exploit divergent niches and segregate in one or more dimensions. Seasonal variations in environmental conditions and energy requirements can influence the mechanisms and the degree of niche segregation. However, studies have overlooked the multi-dimensional aspect of niche segregation over the whole annual cycle, and key facets of species co-existence still remain ambiguous. The present study provides insights into the niche use and partitioning of two morphologically and ecologically similar seabirds, the common (CDP, Pelecanoides urinatrix) and the South Georgian diving petrel (SGDP, Pelecanoides georgicus). Using phenology, at-sea distribution, diving behavior and isotopic data (during the incubation, chick-rearing and non-breeding periods), we show that the degree of partitioning was highly stage-dependent. During the breeding season, the greater niche segregation during chick-rearing than incubation supported the hypothesis that resource partitioning increases during energetically demanding periods. During the post breeding period, while species-specific latitudinal differences were expected (species specific water mass preference), CDP and SGDP also migrated in divergent directions. This segregation in migration area may not be only a response to the selective pressure arising from competition avoidance between sympatric species, but instead, could reflect past evolutionary divergence. Such stage-dependent and context-dependent niche segregation demonstrates the importance of integrative approaches combining techniques from different fields, throughout the entire annual cycle, to better understand the co-existence of ecologically similar species. This is particularly relevant in order to fully understand the short and long-term effects of ongoing environmental changes on species distributions and communities.This work demonstrates the need of integrative multi-dimensional approaches combining concepts and techniques from different fields to understand the mechanism and causal factors of niche segregation.
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Affiliation(s)
- Aymeric Fromant
- grid.1021.20000 0001 0526 7079School of Life and Environmental Sciences, Deakin University, 221 Burwood Hwy, Burwood, VIC 3125 Australia ,grid.452338.b0000 0004 0638 6741Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS–La Rochelle Université, 79360 Villiers-en-Bois, France
| | - John P. Y. Arnould
- grid.1021.20000 0001 0526 7079School of Life and Environmental Sciences, Deakin University, 221 Burwood Hwy, Burwood, VIC 3125 Australia
| | - Karine Delord
- grid.452338.b0000 0004 0638 6741Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS–La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Grace J. Sutton
- grid.1021.20000 0001 0526 7079School of Life and Environmental Sciences, Deakin University, 221 Burwood Hwy, Burwood, VIC 3125 Australia
| | - Alice Carravieri
- grid.11698.370000 0001 2169 7335Littoral Environnement Et Sociétés (LIENSs), UMR 7266 CNRS–La Rochelle Université, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Paco Bustamante
- grid.11698.370000 0001 2169 7335Littoral Environnement Et Sociétés (LIENSs), UMR 7266 CNRS–La Rochelle Université, 2 rue Olympe de Gouges, 17000 La Rochelle, France ,grid.440891.00000 0001 1931 4817Institut Universitaire de France (IUF), 1 rue Descartes, 75005 Paris, France
| | - Colin M. Miskelly
- grid.488640.60000 0004 0483 4475Museum of New Zealand Te Papa Tongarewa, PO Box 467, Wellington, 6140 New Zealand
| | - Akiko Kato
- grid.452338.b0000 0004 0638 6741Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS–La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Maud Brault-Favrou
- grid.11698.370000 0001 2169 7335Littoral Environnement Et Sociétés (LIENSs), UMR 7266 CNRS–La Rochelle Université, 2 rue Olympe de Gouges, 17000 La Rochelle, France
| | - Yves Cherel
- grid.452338.b0000 0004 0638 6741Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS–La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Charles-André Bost
- grid.452338.b0000 0004 0638 6741Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 CNRS–La Rochelle Université, 79360 Villiers-en-Bois, France
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Shero MR, Dale J, Seymour AC, Hammill MO, Mosnier A, Mongrain S, Johnston DW. Tracking wildlife energy dynamics with unoccupied aircraft systems and three‐dimensional photogrammetry. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michelle R. Shero
- Biology Department Woods Hole Oceanographic Institution Woods Hole MA USA
| | - Julian Dale
- Division of Marine Science & Conservation Nicholas School of the Environment Duke University Marine Lab Beaufort NC USA
| | - Alexander C. Seymour
- Division of Marine Science & Conservation Nicholas School of the Environment Duke University Marine Lab Beaufort NC USA
| | - Mike O. Hammill
- Department of Fisheries and Oceans Canada Institut Maurice Lamontagne Mont‐Joli QC Canada
| | - Arnaud Mosnier
- Department of Fisheries and Oceans Canada Institut Maurice Lamontagne Mont‐Joli QC Canada
| | - Samuel Mongrain
- Department of Fisheries and Oceans Canada Institut Maurice Lamontagne Mont‐Joli QC Canada
| | - David W. Johnston
- Division of Marine Science & Conservation Nicholas School of the Environment Duke University Marine Lab Beaufort NC USA
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13
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Optimal diving and oxygen use. Anim Behav 2021. [DOI: 10.1016/j.anbehav.2021.10.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Keen KA, Beltran RS, Pirotta E, Costa DP. Emerging themes in Population Consequences of Disturbance models. Proc Biol Sci 2021; 288:20210325. [PMID: 34428966 PMCID: PMC8385386 DOI: 10.1098/rspb.2021.0325] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 07/29/2021] [Indexed: 12/21/2022] Open
Abstract
Assessing the non-lethal effects of disturbance from human activities is necessary for wildlife conservation and management. However, linking short-term responses to long-term impacts on individuals and populations is a significant hurdle for evaluating the risks of a proposed activity. The Population Consequences of Disturbance (PCoD) framework conceptually describes how disturbance can lead to changes in population dynamics, and its real-world application has led to a suite of quantitative models that can inform risk assessments. Here, we review PCoD models that forecast the possible consequences of a range of disturbance scenarios for marine mammals. In so doing, we identify common themes and highlight general principles to consider when assessing risk. We find that, when considered holistically, these models provide valuable insights into which contextual factors influence a population's degree of exposure and sensitivity to disturbance. We also discuss model assumptions and limitations, identify data gaps and suggest future research directions to enable PCoD models to better inform risk assessments and conservation and management decisions. The general principles explored can help wildlife managers and practitioners identify and prioritize the populations most vulnerable to disturbance and guide industry in planning activities that avoid or mitigate population-level effects.
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Affiliation(s)
- Kelly A. Keen
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Roxanne S. Beltran
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
| | - Enrico Pirotta
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, UK
- School of Biological, Earth, and Environmental Sciences, University College Cork, Cork, Ireland
| | - Daniel P. Costa
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California, Santa Cruz, CA, USA
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15
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Blawas AM, Nowacek DP, Rocho-Levine J, Robeck TR, Fahlman A. Scaling of heart rate with breathing frequency and body mass in cetaceans. Philos Trans R Soc Lond B Biol Sci 2021; 376:20200223. [PMID: 34121456 PMCID: PMC8200651 DOI: 10.1098/rstb.2020.0223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2021] [Indexed: 01/23/2023] Open
Abstract
Plasticity in the cardiac function of a marine mammal facilitates rapid adjustments to the contrasting metabolic demands of breathing at the surface and diving during an extended apnea. By matching their heart rate (fH) to their immediate physiological needs, a marine mammal can improve its metabolic efficiency and maximize the proportion of time spent underwater. Respiratory sinus arrhythmia (RSA) is a known modulation of fH that is driven by respiration and has been suggested to increase cardiorespiratory efficiency. To investigate the presence of RSA in cetaceans and the relationship between fH, breathing rate (fR) and body mass (Mb), we measured simultaneous fH and fR in five cetacean species in human care. We found that a higher fR was associated with a higher mean instantaneous fH (ifH) and minimum ifH of the RSA. By contrast, fH scaled inversely with Mb such that larger animals had lower mean and minimum ifHs of the RSA. There was a significant allometric relationship between maximum ifH of the RSA and Mb, but not fR, which may indicate that this parameter is set by physical laws and not adjusted dynamically with physiological needs. RSA was significantly affected by fR and was greatly reduced with small increases in fR. Ultimately, these data show that surface fHs of cetaceans are complex and the fH patterns we observed are controlled by several factors. We suggest the importance of considering RSA when interpreting fH measurements and particularly how fR may drive fH changes that are important for efficient gas exchange. This article is part of the theme issue 'Measuring physiology in free-living animals (Part I)'.
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Affiliation(s)
- Ashley M. Blawas
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 28516, USA
| | - Douglas P. Nowacek
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 28516, USA
- Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | | | | | - Andreas Fahlman
- Fundación Oceanogràfic de la Comunitat Valenciana, Valencia, Spain 46005
- Global Diving Research, Inc., Ottawa, Canada, K2 J 5E8
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16
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McWhinnie RB, Sckrabulis JP, Raffel TR. Temperature and mass scaling affect cutaneous and pulmonary respiratory performance in a diving frog. Integr Zool 2021; 16:712-728. [PMID: 34002945 DOI: 10.1111/1749-4877.12551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Global climate change is altering patterns of temperature variation, with unpredictable consequences for species and ecosystems. The Metabolic Theory of Ecology (MTE) provides a powerful framework for predicting climate change impacts on ectotherm metabolic performance. MTE postulates that physiological and ecological processes are limited by organism metabolic rates, which scale predictably with body mass and temperature. The purpose of this study was to determine if different metabolic proxies generate different empirical estimates of key MTE model parameters for the aquatic frog Xenopus laevis when allowed to exhibit normal diving behavior. We used a novel methodological approach in combining a flow-through respirometry setup with the open-source Arduino platform to measure mass and temperature effects on 4 different proxies for whole-body metabolism (total O2 consumption, cutaneous O2 consumption, pulmonary O2 consumption, and ventilation frequency), following thermal acclimation to one of 3 temperatures (8°C, 17°C, or 26°C). Different metabolic proxies generated different mass-scaling exponents (b) and activation energy (EA ) estimates, highlighting the importance of metabolic proxy selection when parameterizing MTE-derived models. Animals acclimated to 17°C had higher O2 consumption across all temperatures, but thermal acclimation did not influence estimates of key MTE parameters EA and b. Cutaneous respiration generated lower MTE parameters than pulmonary respiration, consistent with temperature and mass constraints on dissolved oxygen availability, SA:V ratios, and diffusion distances across skin. Our results show that the choice of metabolic proxy can have a big impact on empirical estimates for key MTE model parameters.
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Affiliation(s)
- Ryan B McWhinnie
- Department of Biological Sciences, Oakland University, Rochester, Michigan, USA
| | - Jason P Sckrabulis
- Department of Biological Sciences, Oakland University, Rochester, Michigan, USA
| | - Thomas R Raffel
- Department of Biological Sciences, Oakland University, Rochester, Michigan, USA
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17
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Adachi T, Takahashi A, Costa DP, Robinson PW, Hückstädt LA, Peterson SH, Holser RR, Beltran RS, Keates TR, Naito Y. Forced into an ecological corner: Round-the-clock deep foraging on small prey by elephant seals. SCIENCE ADVANCES 2021; 7:7/20/eabg3628. [PMID: 33980496 PMCID: PMC8115928 DOI: 10.1126/sciadv.abg3628] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 03/22/2021] [Indexed: 06/01/2023]
Abstract
Small mesopelagic fishes dominate the world's total fish biomass, yet their ecological importance as prey for large marine animals is poorly understood. To reveal the little-known ecosystem dynamics, we identified prey, measured feeding events, and quantified the daily energy balance of 48 deep-diving elephant seals throughout their oceanic migrations by leveraging innovative technologies: animal-borne smart accelerometers and video cameras. Seals only attained positive energy balance after feeding 1000 to 2000 times per day on small fishes, which required continuous deep diving (80 to 100% of each day). Interspecies allometry suggests that female elephant seals have exceptional diving abilities relative to their body size, enabling them to exploit a unique foraging niche on small but abundant mesopelagic fish. This unique foraging niche requires extreme round-the-clock deep diving, limiting the behavioral plasticity of elephant seals to a changing mesopelagic ecosystem.
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Affiliation(s)
- Taiki Adachi
- National Institute of Polar Research, Tachikawa, Tokyo, Japan.
| | | | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Patrick W Robinson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Luis A Hückstädt
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, USA
| | - Sarah H Peterson
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- Institute of Marine Sciences, 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
| | - Roxanne S Beltran
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Theresa R Keates
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Yasuhiko Naito
- National Institute of Polar Research, Tachikawa, Tokyo, Japan
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18
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Brischoux F, Lillywhite HB, Shine R, Pinaud D. Osmoregulatory ability predicts geographical range size in marine amniotes. Proc Biol Sci 2021; 288:20203191. [PMID: 33823670 PMCID: PMC8059505 DOI: 10.1098/rspb.2020.3191] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/04/2021] [Indexed: 12/21/2022] Open
Abstract
Species that are distributed over wide geographical ranges are likely to encounter a greater diversity of environmental conditions than do narrowly distributed taxa, and thus we expect a correlation between size of geographical range and breadth of physiological tolerances to abiotic challenges. That correlation could arise either because higher physiological capacity enables range expansion, or because widely distributed taxa experience more intense (but spatially variable) selection on physiological tolerances. The invasion of oceanic habitats by amniotic vertebrates provides an ideal system with which to test the predicted correlation between range size and physiological tolerances, because all three lineages that have secondarily moved into marine habitats (mammals, birds, reptiles) exhibit morphological and physiological adaptations to excrete excess salt. Our analyses of data on 62 species (19 mammals, 18 birds, 24 reptiles) confirm that more-widely distributed taxa encounter habitats with a wider range of salinities, and that they have higher osmoregulatory ability as determined by sodium concentrations in fluids expelled from salt-excreting organs. This result remains highly significant even in models that incorporate additional explanatory variables such as metabolic mode, body size and dietary habits. Physiological data thus may help to predict potential range size and perhaps a species' vulnerability to anthropogenic disturbance.
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Affiliation(s)
- François Brischoux
- Centre d'Etudes Biologiques de Chizé, CEBC UMR 7372 CNRS-La Rochelle Université, 79360 Villiers en Bois, France
| | | | - Richard Shine
- Department of Biological Sciences, Macquarie University, New South Wales 2109, Australia
| | - David Pinaud
- Centre d'Etudes Biologiques de Chizé, CEBC UMR 7372 CNRS-La Rochelle Université, 79360 Villiers en Bois, France
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19
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Fish heating tolerance scales similarly across individual physiology and populations. Commun Biol 2021; 4:264. [PMID: 33649450 PMCID: PMC7921436 DOI: 10.1038/s42003-021-01773-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 02/01/2021] [Indexed: 11/12/2022] Open
Abstract
Extrapolating patterns from individuals to populations informs climate vulnerability models, yet biological responses to warming are uncertain at both levels. Here we contrast data on the heating tolerances of fishes from laboratory experiments with abundance patterns of wild populations. We find that heating tolerances in terms of individual physiologies in the lab and abundance in the wild decline with increasing temperature at the same rate. However, at a given acclimation temperature or optimum temperature, tropical individuals and populations have broader heating tolerances than temperate ones. These congruent relationships implicate a tight coupling between physiological and demographic processes underpinning macroecological patterns, and identify vulnerability in both temperate and tropical species. Nicholas Payne et al. use physiological and population-level abundance data from 823 fish species to examine how heating tolerance scales at both the individual and population level. This study shows that heating tolerance declines in the lab and the wild at the same rate, and for a given temperature, individuals and populations from tropical areas have broader heating tolerances than temperate species.
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20
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Ultrahigh foraging rates of Baikal seals make tiny endemic amphipods profitable in Lake Baikal. Proc Natl Acad Sci U S A 2020; 117:31242-31248. [PMID: 33199633 DOI: 10.1073/pnas.2014021117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Understanding what, how, and how often apex predators hunt is important due to their disproportionately large effects on ecosystems. In Lake Baikal with rich endemic fauna, Baikal seals appear to eat, in addition to fishes, a tiny (<0.1 g) endemic amphipod Macrohectopus branickii (the world's only freshwater planktonic species). Yet, its importance as prey to seals is unclear. Globally, amphipods are rarely targeted by single-prey feeding (i.e., nonfilter-feeding) mammals, presumably due to their small size. If M. branickii is energetically important prey, Baikal seals would exhibit exceptionally high foraging rates, potentially with behavioral and morphological specializations. Here, we used animal-borne accelerometers and video cameras to record Baikal seal foraging behavior. Unlike the prevailing view that they predominantly eat fishes, they also hunted M. branickii at the highest rates (mean, 57 individuals per dive) ever recorded for single-prey feeding aquatic mammals, leading to thousands of catches per day. These rates were achieved by gradual changes in dive depth following the diel vertical migration of M. branickii swarms. Examining museum specimens revealed that Baikal seals have the most specialized comb-like postcanine teeth in the subfamily Phocinae, allowing them to expel water while retaining prey during high-speed foraging. Our findings show unique mammal-amphipod interactions in an ancient lake, demonstrating that organisms even smaller than krill can be important prey for single-prey feeding aquatic mammals if the environment and predators' adaptations allow high foraging rates. Further, our finding that Baikal seals directly eat macroplankton may explain why they are so abundant in this ultraoligotrophic lake.
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21
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Kahane-Rapport SR, Savoca MS, Cade DE, Segre PS, Bierlich KC, Calambokidis J, Dale J, Fahlbusch JA, Friedlaender AS, Johnston DW, Werth AJ, Goldbogen JA. Lunge filter feeding biomechanics constrain rorqual foraging ecology across scale. J Exp Biol 2020; 223:jeb224196. [PMID: 32820028 DOI: 10.1242/jeb.224196] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 08/13/2020] [Indexed: 10/23/2022]
Abstract
Fundamental scaling relationships influence the physiology of vital rates, which in turn shape the ecology and evolution of organisms. For diving mammals, benefits conferred by large body size include reduced transport costs and enhanced breath-holding capacity, thereby increasing overall foraging efficiency. Rorqual whales feed by engulfing a large mass of prey-laden water at high speed and filtering it through baleen plates. However, as engulfment capacity increases with body length (engulfment volume∝body length3.57), the surface area of the baleen filter does not increase proportionally (baleen area∝body length1.82), and thus the filtration time of larger rorquals predictably increases as the baleen surface area must filter a disproportionally large amount of water. We predicted that filtration time should scale with body length to the power of 1.75 (filter time∝body length1.75). We tested this hypothesis on four rorqual species using multi-sensor tags with corresponding unoccupied aircraft systems-based body length estimates. We found that filter time scales with body length to the power of 1.79 (95% CI: 1.61-1.97). This result highlights a scale-dependent trade-off between engulfment capacity and baleen area that creates a biomechanical constraint to foraging through increased filtration time. Consequently, larger whales must target high-density prey patches commensurate to the gulp size to meet their increased energetic demands. If these optimal patches are absent, larger rorquals may experience reduced foraging efficiency compared with smaller whales if they do not match their engulfment capacity to the size of targeted prey aggregations.
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Affiliation(s)
- S R Kahane-Rapport
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - M S Savoca
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - D E Cade
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - P S Segre
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - K C Bierlich
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 27710, USA
| | - J Calambokidis
- Cascadia Research Collective, 218 W. 4th Ave., Olympia, WA 98501, USA
| | - J Dale
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 27710, USA
| | - J A Fahlbusch
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
| | - A S Friedlaender
- Institute of Marine Sciences, University of California, Santa Cruz, Santa Cruz, CA, USA
| | - D W Johnston
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 27710, USA
| | - A J Werth
- Department of Biology, Hampden-Sydney College, Hampden-Sydney, VA 23943, USA
| | - J A Goldbogen
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA
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22
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Lapsansky AB, Zatz D, Tobalske BW. Alcids 'fly' at efficient Strouhal numbers in both air and water but vary stroke velocity and angle. eLife 2020; 9:55774. [PMID: 32602463 PMCID: PMC7332295 DOI: 10.7554/elife.55774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 06/20/2020] [Indexed: 12/01/2022] Open
Abstract
Birds that use their wings for ‘flight’ in both air and water are expected to fly poorly in each fluid relative to single-fluid specialists; that is, these jacks-of-all-trades should be the masters of none. Alcids exhibit exceptional dive performance while retaining aerial flight. We hypothesized that alcids maintain efficient Strouhal numbers and stroke velocities across air and water, allowing them to mitigate the costs of their ‘fluid generalism’. We show that alcids cruise at Strouhal numbers between 0.10 and 0.40 – on par with single-fluid specialists – in both air and water but flap their wings ~ 50% slower in water. Thus, these species either contract their muscles at inefficient velocities or maintain a two-geared muscle system, highlighting a clear cost to using the same morphology for locomotion in two fluids. Additionally, alcids varied stroke-plane angle between air and water and chord angle during aquatic flight, expanding their performance envelope.
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Affiliation(s)
- Anthony B Lapsansky
- Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, Missoula, United States
| | | | - Bret W Tobalske
- Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, Missoula, United States
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23
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Bennet DG, Horton TW, Goldstien SJ, Rowe L, Briskie JV. Seasonal and annual variation in the diving behaviour of Hutton's shearwater (Puffinus huttoni). NEW ZEALAND JOURNAL OF ZOOLOGY 2020. [DOI: 10.1080/03014223.2020.1767660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Della G. Bennet
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Travis W. Horton
- Department of Geological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Sharyn J. Goldstien
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Lindsay Rowe
- Hutton’s Shearwater Charitable Trust, Kaikōura, New Zealand
| | - James V. Briskie
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
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24
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Verberk WCEP, Calosi P, Brischoux F, Spicer JI, Garland T, Bilton DT. Universal metabolic constraints shape the evolutionary ecology of diving in animals. Proc Biol Sci 2020; 287:20200488. [PMID: 32453989 PMCID: PMC7287373 DOI: 10.1098/rspb.2020.0488] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 04/27/2020] [Indexed: 01/07/2023] Open
Abstract
Diving as a lifestyle has evolved on multiple occasions when air-breathing terrestrial animals invaded the aquatic realm, and diving performance shapes the ecology and behaviour of all air-breathing aquatic taxa, from small insects to great whales. Using the largest dataset yet assembled, we show that maximum dive duration increases predictably with body mass in both ectotherms and endotherms. Compared to endotherms, ectotherms can remain submerged for longer, but the mass scaling relationship for dive duration is much steeper in endotherms than in ectotherms. These differences in diving allometry can be fully explained by inherent differences between the two groups in their metabolic rate and how metabolism scales with body mass and temperature. Therefore, we suggest that similar constraints on oxygen storage and usage have shaped the evolutionary ecology of diving in all air-breathing animals, irrespective of their evolutionary history and metabolic mode. The steeper scaling relationship between body mass and dive duration in endotherms not only helps explain why the largest extant vertebrate divers are endothermic rather than ectothermic, but also fits well with the emerging consensus that large extinct tetrapod divers (e.g. plesiosaurs, ichthyosaurs and mosasaurs) were endothermic.
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Affiliation(s)
- Wilco C E P Verberk
- Department of Animal Ecology and Ecophysiology, Radboud University, PO Box 9010, 6500 GL Nijmegen, The Netherlands
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
| | - Piero Calosi
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, Québec, Canada G5 L 3A1
| | - François Brischoux
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS-La Rochelle Université, 79360 Villiers en Bois, France
| | - John I Spicer
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
| | - Theodore Garland
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA
| | - David T Bilton
- Marine Biology and Ecology Research Centre, School of Biological and Marine Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK
- Department of Zoology, University of Johannesburg, PO Box 524, Auckland Park, 2006 Johannesburg, South Africa
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25
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March D, Boehme L, Tintoré J, Vélez‐Belchi PJ, Godley BJ. Towards the integration of animal-borne instruments into global ocean observing systems. GLOBAL CHANGE BIOLOGY 2020; 26:586-596. [PMID: 31675456 PMCID: PMC7027834 DOI: 10.1111/gcb.14902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/10/2019] [Accepted: 10/17/2019] [Indexed: 05/05/2023]
Abstract
Marine animals are increasingly instrumented with environmental sensors that provide large volumes of oceanographic data. Here, we conduct an innovative and comprehensive global analysis to determine the potential contribution of animal-borne instruments (ABI) into ocean observing systems (OOSs) and provide a foundation to establish future integrated ocean monitoring programmes. We analyse the current gaps of the long-term Argo observing system (>1.5 million profiles) and assess its spatial overlap with the distribution of marine animals across eight major species groups (tuna and billfishes, sharks and rays, marine turtles, pinnipeds, cetaceans, sirenians, flying seabirds and penguins). We combine distribution ranges of 183 species and satellite tracking observations from >3,000 animals. Our analyses identify potential areas where ABI could complement OOS. Specifically, ABI have the potential to fill gaps in marginal seas, upwelling areas, the upper 10 m of the water column, shelf regions and polewards of 60° latitude. Our approach provides the global baseline required to plan the integration of ABI into global and regional OOS while integrating conservation and ocean monitoring priorities.
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Affiliation(s)
- David March
- Marine Turtle Research GroupCentre for Ecology and ConservationUniversity of ExeterPenrynUK
- ICTS SOCIB – Balearic Islands Coastal Observing and Forecasting SystemParc BitPalma de MallorcaSpain
| | - Lars Boehme
- Sea Mammal Research UnitScottish Oceans InstituteUniversity of St AndrewsSt AndrewsUK
| | - Joaquín Tintoré
- ICTS SOCIB – Balearic Islands Coastal Observing and Forecasting SystemParc BitPalma de MallorcaSpain
- IMEDEA (CSIC‐UIB)Mediterranean Institute of Advanced StudiesEsporlesSpain
| | | | - Brendan J. Godley
- Marine Turtle Research GroupCentre for Ecology and ConservationUniversity of ExeterPenrynUK
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26
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Abstract
The largest animals are baleen filter feeders that exploit large aggregations of small-bodied plankton. Although this feeding mechanism has evolved multiple times in marine vertebrates, rorqual whales exhibit a distinct lunge filter feeding mode that requires extreme physiological adaptations-most of which remain poorly understood. Here, we review the biomechanics of the lunge feeding mechanism in rorqual whales that underlies their extraordinary foraging performance and gigantic body size.
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Affiliation(s)
- Robert E Shadwick
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jean Potvin
- Department of Physics, Saint Louis University, St. Louis, Missouri
| | - Jeremy A Goldbogen
- Department of Biology, Hopkins Marine Station, Stanford University, Pacific Grove, California
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27
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Migratory strategies of juvenile northern fur seals (Callorhinus ursinus): bridging the gap between pups and adults. Sci Rep 2019; 9:13921. [PMID: 31558737 PMCID: PMC6763446 DOI: 10.1038/s41598-019-50230-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 09/02/2019] [Indexed: 11/08/2022] Open
Abstract
In species exhibiting differential migration by sex and age, understanding what differences exist, and the adaptive reasons for these differences is critical for determining how demographic groups will respond to environmental variability and anthropogenic perturbations. We used satellite-telemetered movement and diving data to investigate differential migration and its ontogeny in a highly migratory North Pacific Ocean predator, the northern fur seal (Callorhinus ursinus; NFS), with a focus on understudied juvenile (1- to 2-year-old) animals. We instrumented 71 juvenile NFS in two years (2006-07 and 2007-08) at three major North American breeding sites and compared their migratory strategies with pups and adults. Although sexual dimorphism is strong in adult NFS, only weak differences in body mass between sexes were found in juveniles, which had similar body mass to pups (~3-4 months). However, unlike widely-dispersed pups, juvenile male and female NFS dispersed in different directions, and used different habitats characterized by distinct hydrography and prey assemblages during migration, similar to breeding adults. Juvenile diving behavior differed only modestly among habitats and between sexes, consistent with weak differences in body mass. Evidence of habitat sexual segregation by juvenile NFS contradicts previous hypotheses that physiological differences predominantly drive the ontogeny of differential migration.
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Lapsansky AB, Tobalske BW. Upstroke-based acceleration and head stabilization are the norm for the wing-propelled swimming of alcid seabirds. ACTA ACUST UNITED AC 2019; 222:jeb.201285. [PMID: 31160426 DOI: 10.1242/jeb.201285] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/28/2019] [Indexed: 11/20/2022]
Abstract
Alcids, a family of seabirds including murres, guillemots and puffins, exhibit the greatest mass-specific dive depths and durations of any birds or mammals. These impressive diving capabilities have motivated numerous studies on the biomechanics of alcid swimming and diving, with one objective being to compare stroke-acceleration patterns of swimming alcids with those of penguins, where upstroke and downstroke are used for horizontal acceleration. Studies of free-ranging, descending alcids have found that alcids accelerate in the direction of travel during both their upstroke and downstroke, but only at depths <20 m, whereas studies of alcids swimming horizontally report upstroke-based acceleration to be rare (≤16% of upstrokes). We hypothesized that swimming trajectory, via its interaction with buoyancy, determines the magnitude of acceleration produced during the upstroke. Thus, we studied the stroke-acceleration relationships of five species of alcid swimming freely at the Alaska SeaLife Center using videography and kinematic analysis. Contrary to our prediction, we found that upstroke-based acceleration is very common (87% of upstrokes) during both descending and horizontal swimming. We reveal that head-damping - wherein an animal extends and retracts its head to offset periodic accelerations - is common in swimming alcids, underscoring the importance of head stabilization during avian locomotion.
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Affiliation(s)
- Anthony B Lapsansky
- Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
| | - Bret W Tobalske
- Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
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29
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Climate and symbioses with ants modulate leaf/stem scaling in epiphytes. Sci Rep 2019; 9:2624. [PMID: 30796304 PMCID: PMC6385368 DOI: 10.1038/s41598-019-39853-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 01/31/2019] [Indexed: 01/12/2023] Open
Abstract
In most seed plants, leaf size is isometrically related to stem cross-sectional area, a relationship referred to as Corner's rule. When stems or leaves acquire a new function, for instance in ant-plant species with hollow stems occupied by ants, their scaling is expected to change. Here we use a lineage of epiphytic ant-plants to test how the evolution of ant-nesting structures in species with different levels of symbiotic dependence has impacted leaf/stem scaling. We expected that leaf size would correlate mostly with climate, while stem diameter would change with domatium evolution. Using a trait dataset from 286 herbarium specimens, field and greenhouse observations, climatic data, and a range of phylogenetic-comparative analyses, we detected significant shifts in leaf/stem scaling, mirroring the evolution of specialized symbioses. Our analyses support both predictions, namely that stem diameter change is tied to symbiosis evolution (ant-nesting structures), while leaf size is independently correlated with rainfall variables. Our study highlights how independent and divergent selective pressures can alter allometry. Because shifts in scaling relationships can impact the costs and benefits of mutualisms, studying allometry in mutualistic interactions may shed unexpected light on the stability of cooperation among species.
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Orgeret F, Cox SL, Weimerskirch H, Guinet C. Body condition influences ontogeny of foraging behavior in juvenile southern elephant seals. Ecol Evol 2019; 9:223-236. [PMID: 30680109 PMCID: PMC6341977 DOI: 10.1002/ece3.4717] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/12/2018] [Accepted: 10/26/2018] [Indexed: 11/21/2022] Open
Abstract
Ontogeny of diving and foraging behavior in marine top predators is poorly understood despite its importance in population recruitment. This lack of knowledge is partly due to the difficulties of monitoring juveniles in the wild, which is linked to high mortality early in life. Pinnipeds are good models for studying the development of foraging behaviors because juveniles are large enough to robustly carry tracking devices for many months. Moreover, parental assistance is absent after a juvenile departs for its first foraging trip, minimizing confounding effects of parental input on the development of foraging skills. In this study, we tracked 20 newly weaned juvenile southern elephant seals from Kerguelen Islands for up to 338 days during their first trip at sea following weaning. We used a new generation of satellite relay tags, which allow for the transmission of dive, accelerometer, and location data. We also monitored, at the same time, nine adult females from the colony during their post-breeding trips, in order to compare diving and foraging behaviors. Juveniles showed a gradual improvement through time in their foraging skills. Like adults females, they remarkably adjusted their swimming effort according to temporal changes in buoyancy (i.e., a proxy of their body condition). They also did not appear to exceed their aerobic physiological diving limits, although dives were constrained by their smaller size compared to adults. Changes in buoyancy appeared to also influence their decision to either keep foraging or return to land, alongside the duration of their haul outs and choice of foraging habitat (oceanic vs. plateau). Further studies are thus needed to better understand how patterns in juveniles survival, and therefore elephant seal populations, might be affected by their changes in foraging skills and changes in their environmental conditions.
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Affiliation(s)
- Florian Orgeret
- Centre d’Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Université de La RochelleVilliers‐en‐BoisFrance
| | - Sam L. Cox
- Centre d’Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Université de La RochelleVilliers‐en‐BoisFrance
- Centre National d'Études Spatiales (CNES)18 Avenue Edouard Belin31400 ToulouseFrance
- MARBEC (Institut de Recherche pour le Developpemente; IRD)Station Ifremer de Sete, Avenue Jean Monnet, CS 30171, 34203SèteFrance
| | - Henri Weimerskirch
- Centre d’Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Université de La RochelleVilliers‐en‐BoisFrance
| | - Christophe Guinet
- Centre d’Etudes Biologique de ChizéUMR 7372 ‐ CNRS & Université de La RochelleVilliers‐en‐BoisFrance
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Kahane‐Rapport SR, Goldbogen JA. Allometric scaling of morphology and engulfment capacity in rorqual whales. J Morphol 2018; 279:1256-1268. [DOI: 10.1002/jmor.20846] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/16/2018] [Accepted: 05/17/2018] [Indexed: 11/10/2022]
Affiliation(s)
- Shirel R. Kahane‐Rapport
- Department of Biology, Hopkins Marine Station Stanford University 120 Ocean View Blvd, Pacific Grove California
| | - Jeremy A. Goldbogen
- Department of Biology, Hopkins Marine Station Stanford University 120 Ocean View Blvd, Pacific Grove California
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Rivero JLL. Locomotor muscle fibre heterogeneity and metabolism in the fastest large-bodied rorqual: the fin whale ( Balaenoptera physalus). ACTA ACUST UNITED AC 2018; 221:jeb.177758. [PMID: 29691309 DOI: 10.1242/jeb.177758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/18/2018] [Indexed: 11/20/2022]
Abstract
From a terrestrial ancestry, the fin whale (Balaenoptera physalus) is one of the largest animals on Earth with a sprinter anti-predator strategy, and a characteristic feeding mode, lunge feeding, which involves bouts of high-intensity muscle activity demanding high metabolic output. We investigated the locomotor muscle morphology and metabolism of this cetacean to determine whether its muscle profile (1) explains this unique swimming performance and feeding behaviour, (2) is or is not homogeneous within the muscle, and (3) predicts allometric variations inherent to an extreme body size. A predominantly fast-glycolytic phenotype characterized the fin whale locomotor muscle, composed of abundant fast-twitch (type IIA) fibres with high glycolytic potential, low oxidative capacity, relatively small size, and reduced number of capillaries. Compared with superficial areas, deep regions of this muscle exhibited a slower and more oxidative profile, suggesting a division of labour between muscle strata. As expected, the fin whale locomotor muscle only expressed the two slowest myosin heavy chain isoforms (I and IIA). However, it displayed anaerobic (glycolytic) and aerobic (lipid-based metabolism) capabilities higher than would be predicted from the allometric perspective of its extreme body size. Relationships between muscle metabolism and body mass were fibre-type specific. The 'sprinter' profile of the fin whale swimming muscle, particularly of its superficial compartment, supports physiological demands during both high-speed swimming and the lunge, when energy expenditure reaches maximal or supramaximal levels. Comparatively, the slower and more oxidative profile of the deep compartment of this muscle seems to be well designed for sustained, low-intensity muscle activity during routine swimming.
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Affiliation(s)
- José-Luis L Rivero
- Laboratory of Muscular Biopathology, Department of Comparative Anatomy and Pathological Anatomy, Faculty of Veterinary Sciences, University of Cordoba, Campus Universitario de Rabanales, 14014 Cordoba, Spain
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Goldbogen JA, Madsen PT. The evolution of foraging capacity and gigantism in cetaceans. ACTA ACUST UNITED AC 2018; 221:221/11/jeb166033. [PMID: 29895582 DOI: 10.1242/jeb.166033] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The extant diversity and rich fossil record of cetaceans provides an extraordinary evolutionary context for investigating the relationship between form, function and ecology. The transition from terrestrial to marine ecosystems is associated with a complex suite of morphological and physiological adaptations that were required for a fully aquatic mammalian life history. Two specific functional innovations that characterize the two great clades of cetaceans, echolocation in toothed whales (Odontoceti) and filter feeding in baleen whales (Mysticeti), provide a powerful comparative framework for integrative studies. Both clades exhibit gigantism in multiple species, but we posit that large body size may have evolved for different reasons and in response to different ecosystem conditions. Although these foraging adaptations have been studied using a combination of experimental and tagging studies, the precise functional drivers and consequences of morphological change within and among these lineages remain less understood. Future studies that focus at the interface of physiology, ecology and paleontology will help elucidate how cetaceans became the largest predators in aquatic ecosystems worldwide.
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Affiliation(s)
- J A Goldbogen
- Department of Biology, Hopkins Marine Station, Stanford University, 120 Ocean View Boulevard, Pacific Grove, CA 93950, USA
| | - P T Madsen
- Zoophysiology, Department of Bioscience, Aarhus University, C.F. Møllers Allé 3, 8000 Aarhus C, Denmark.,Aarhus Institute of Advanced Studies, Høegh-Guldbergs Gade 6B, DK-8000 Aarhus C, Denmark
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35
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Graf PM, Wilson RP, Sanchez LC, Hacklӓnder K, Rosell F. Diving behavior in a free-living, semi-aquatic herbivore, the Eurasian beaver Castor fiber. Ecol Evol 2018; 8:997-1008. [PMID: 29375773 PMCID: PMC5773300 DOI: 10.1002/ece3.3726] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/10/2017] [Accepted: 11/15/2017] [Indexed: 11/09/2022] Open
Abstract
Semi-aquatic mammals have secondarily returned to the aquatic environment, although they spend a major part of their life operating in air. Moving both on land, as well as in, and under water is challenging because such species are considered to be imperfectly adapted to both environments. We deployed accelerometers combined with a depth sensor to study the diving behavior of 12 free-living Eurasian beavers Castor fiber in southeast Norway between 2009 and 2011 to examine the extent to which beavers conformed with mass-dependent dive capacities, expecting them to be poorer than wholly aquatic species. Dives were generally shallow (<1 m) and of short duration (<30 s), suggesting that the majority of dives were aerobic. Dive parameters such as maximum diving depth, dive duration, and bottom phase duration were related to the effort during different dive phases and the maximum depth reached. During the descent, mean vectorial dynamic body acceleration (VeDBA-a proxy for movement power) was highest near the surface, probably due to increased upthrust linked to fur- and lung-associated air. Inconsistently though, mean VeDBA underwater was highest during the ascent when this air would be expected to help drive the animals back to the surface. Higher movement costs during ascents may arise from transporting materials up, the air bubbling out of the fur, and/or the animals' exhaling during the bottom phase of the dive. In a manner similar to other homeotherms, beavers extended both dive and bottom phase durations with diving depth. Deeper dives tended to have a longer bottom phase, although its duration was shortened with increased VeDBA during the bottom phase. Water temperature did not affect diving behavior. Overall, the beavers' dive profile (depth, duration) was similar to other semi-aquatic freshwater divers. However, beavers dived for only 2.8% of their active time, presumably because they do not rely on diving for food acquisition.
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Affiliation(s)
- Patricia Maria Graf
- Institute of Wildlife Biology and Game Management University of Natural Resources and Life Sciences Vienna Austria.,Department of Natural Sciences and Environmental Health Faculty of Technology, Natural Sciences and Maritime Sciences University College of Southeast Norway Telemark Norway
| | | | - Lea Cohen Sanchez
- Institute of Geography School of Geoscience University of Edinburgh Edinburgh UK
| | - Klaus Hacklӓnder
- Institute of Wildlife Biology and Game Management University of Natural Resources and Life Sciences Vienna Austria
| | - Frank Rosell
- Department of Natural Sciences and Environmental Health Faculty of Technology, Natural Sciences and Maritime Sciences University College of Southeast Norway Telemark Norway
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36
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Shao M, Chen B. Effect of sex, temperature, time and flock size on the diving behavior of the wintering Scaly-sided Merganser (Mergus squamatus). AVIAN RESEARCH 2017; 8:9. [DOI: 10.1186/s40657-017-0067-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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37
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Joyce TW, Durban JW, Claridge DE, Dunn CA, Fearnbach H, Parsons KM, Andrews RD, Ballance LT. Physiological, morphological, and ecological tradeoffs influence vertical habitat use of deep-diving toothed-whales in the Bahamas. PLoS One 2017; 12:e0185113. [PMID: 29020021 PMCID: PMC5636075 DOI: 10.1371/journal.pone.0185113] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 09/05/2017] [Indexed: 01/05/2023] Open
Abstract
Dive capacity among toothed whales (suborder: Odontoceti) has been shown to generally increase with body mass in a relationship closely linked to the allometric scaling of metabolic rates. However, two odontocete species tagged in this study, the Blainville’s beaked whale Mesoplodon densirostris and the Cuvier’s beaked whale Ziphius cavirostris, confounded expectations of a simple allometric relationship, with exceptionally long (mean: 46.1 min & 65.4 min) and deep dives (mean: 1129 m & 1179 m), and comparatively small body masses (med.: 842.9 kg & 1556.7 kg). These two species also exhibited exceptionally long recovery periods between successive deep dives, or inter-deep-dive intervals (M. densirostris: med. 62 min; Z. cavirostris: med. 68 min). We examined competing hypotheses to explain observed patterns of vertical habitat use based on body mass, oxygen binding protein concentrations, and inter-deep-dive intervals in an assemblage of five sympatric toothed whales species in the Bahamas. Hypotheses were evaluated using dive data from satellite tags attached to the two beaked whales (M. densirostris, n = 12; Z. cavirostris, n = 7), as well as melon-headed whales Peponocephala electra (n = 13), short-finned pilot whales Globicephala macrorhynchus (n = 15), and sperm whales Physeter macrocephalus (n = 27). Body mass and myoglobin concentration together explained only 36% of the variance in maximum dive durations. The inclusion of inter-deep-dive intervals, substantially improved model fits (R2 = 0.92). This finding supported a hypothesis that beaked whales extend foraging dives by exceeding aerobic dive limits, with the extension of inter-deep-dive intervals corresponding to metabolism of accumulated lactic acid. This inference points to intriguing tradeoffs between body size, access to prey in different depth strata, and time allocation within dive cycles. These tradeoffs and resulting differences in habitat use have important implications for spatial distribution patterns, and relative vulnerabilities to anthropogenic impacts.
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Affiliation(s)
- Trevor W. Joyce
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States of America
- Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
- * E-mail:
| | - John W. Durban
- Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
| | - Diane E. Claridge
- Bahamas Marine Mammal Research Organization, Marsh Harbor, Abaco, Bahamas
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Scotland, United Kingdom
| | - Charlotte A. Dunn
- Bahamas Marine Mammal Research Organization, Marsh Harbor, Abaco, Bahamas
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, Scotland, United Kingdom
| | - Holly Fearnbach
- SR³ SeaLife Response, Rehabilitation, and Research, Mukilteo, Washington, United States of America
| | - Kim M. Parsons
- Marine Mammal Laboratory, Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, Washington, United States of America
| | - Russel D. Andrews
- School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
- Marine Ecology and Telemetry Research, Seabeck, Washington, United States of America
| | - Lisa T. Ballance
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States of America
- Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, California, United States of America
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38
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Naito Y, Costa DP, Adachi T, Robinson PW, Peterson SH, Mitani Y, Takahashi A. Oxygen minimum zone: An important oceanographic habitat for deep-diving northern elephant seals, Mirounga angustirostris. Ecol Evol 2017; 7:6259-6270. [PMID: 28861230 PMCID: PMC5574793 DOI: 10.1002/ece3.3202] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 05/27/2017] [Accepted: 05/30/2017] [Indexed: 11/23/2022] Open
Abstract
Little is known about the foraging behavior of top predators in the deep mesopelagic ocean. Elephant seals dive to the deep biota‐poor oxygen minimum zone (OMZ) (>800 m depth) despite high diving costs in terms of energy and time, but how they successfully forage in the OMZ remains largely unknown. Assessment of their feeding rate is the key to understanding their foraging behavior, but this has been challenging. Here, we assessed the feeding rate of 14 female northern elephant seals determined by jaw motion events (JME) and dive cycle time to examine how feeding rates varied with dive depth, particularly in the OMZ. We also obtained video footage from seal‐mounted videos to understand their feeding in the OMZ. While the diel vertical migration pattern was apparent for most depths of the JME, some very deep dives, beyond the normal diel depth ranges, occurred episodically during daylight hours. The midmesopelagic zone was the main foraging zone for all seals. Larger seals tended to show smaller numbers of JME and lower feeding rates than smaller seals during migration, suggesting that larger seals tended to feed on larger prey to satisfy their metabolic needs. Larger seals also dived frequently to the deep OMZ, possibly because of a greater diving ability than smaller seals, suggesting their dependency on food in the deeper depth zones. Video observations showed that seals encountered the rarely reported ragfish (Icosteus aenigmaticus) in the depths of the OMZ, which failed to show an escape response from the seals, suggesting that low oxygen concentrations might reduce prey mobility. Less mobile prey in OMZ would enhance the efficiency of foraging in this zone, especially for large seals that can dive deeper and longer. We suggest that the OMZ plays an important role in structuring the mesopelagic ecosystem and for the survival and evolution of elephant seals.
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Affiliation(s)
- Yasuhiko Naito
- National Institute of Polar Research Midori-cho Tachikawa, Tokyo Japan
| | - Daniel P Costa
- Long Marine Laboratory Center for Ocean Health Institute of Marine Sciences University of California Santa Cruz CA USA
| | - Taiki Adachi
- National Institute of Polar Research Midori-cho Tachikawa, Tokyo Japan.,Present address: Department of Biological Sciences Graduate School of Science The University of Tokyo Tokyo 113-0032 Japan
| | - Patrick W Robinson
- Long Marine Laboratory Center for Ocean Health Institute of Marine Sciences University of California Santa Cruz CA USA
| | - Sarah H Peterson
- Long Marine Laboratory Center for Ocean Health Institute of Marine Sciences University of California Santa Cruz CA USA
| | - Yoko Mitani
- Field Science Center for Northern Biosphere Hokkaido University Bentencho Hakodate, Hokkaido Japan
| | - Akinori Takahashi
- National Institute of Polar Research Midori-cho Tachikawa, Tokyo Japan
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Halsey LG. Relationships grow with time: a note of caution about energy expenditure‐proxy correlations, focussing on accelerometry as an example. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12822] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lewis G. Halsey
- University of Roehampton Holybourne Avenue LondonSW15 4JD UK
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40
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Minias P, Whittingham LA, Dunn PO. Coloniality and migration are related to selection on MHC genes in birds. Evolution 2016; 71:432-441. [PMID: 27921293 DOI: 10.1111/evo.13142] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/14/2016] [Accepted: 11/16/2016] [Indexed: 12/14/2022]
Abstract
The major histocompatibility complex (MHC) plays a key role in pathogen recognition as a part of the vertebrate adaptive immune system. The great diversity of MHC genes in natural populations is maintained by different forms of balancing selection and its strength should correlate with the diversity of pathogens to which a population is exposed and the rate of exposure. Despite this prediction, little is known about how life-history characteristics affect selection at the MHC. Here, we examined whether the strength of balancing selection on MHC class II genes in birds (as measured with nonsynonymous nucleotide substitutions, dN) was related to their social or migratory behavior, two life-history characteristics correlated with pathogen exposure. Our comparative analysis indicated that the rate of nonsynonymous substitutions was higher in colonial and migratory species than solitary and resident species, suggesting that the strength of balancing selection increases with coloniality and migratory status. These patterns could be attributed to: (1) elevated transmission rates of pathogens in species that breed in dense aggregations, or (2) exposure to a more diverse fauna of pathogens and parasites in migratory species. Our study suggests that differences in social structure and basic ecological traits influence MHC diversity in natural vertebrate populations.
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Affiliation(s)
- Piotr Minias
- Department of Biodiversity Studies and Bioeducation, University of Łódź, Banacha 1/3, 90-237, Łódź, Poland
| | - Linda A Whittingham
- Behavioral and Molecular Ecology Group, Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin
| | - Peter O Dunn
- Behavioral and Molecular Ecology Group, Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin
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41
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Hayward A, Pajuelo M, Haase CG, Anderson DM, Gillooly JF. Common metabolic constraints on dive duration in endothermic and ectothermic vertebrates. PeerJ 2016; 4:e2569. [PMID: 27761347 PMCID: PMC5068442 DOI: 10.7717/peerj.2569] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 09/14/2016] [Indexed: 11/20/2022] Open
Abstract
Dive duration in air-breathing vertebrates is thought to be constrained by the volume of oxygen stored in the body and the rate at which it is consumed (i.e., "oxygen store/usage hypothesis"). The body mass-dependence of dive duration among endothermic vertebrates is largely supportive of this model, but previous analyses of ectothermic vertebrates show no such body mass-dependence. Here we show that dive duration in both endotherms and ectotherms largely support the oxygen store/usage hypothesis after accounting for the well-established effects of temperature on oxygen consumption rates. Analyses of the body mass and temperature dependence of dive duration in 181 species of endothermic vertebrates and 29 species of ectothermic vertebrates show that dive duration increases as a power law with body mass, and decreases exponentially with increasing temperature. Thus, in the case of ectothermic vertebrates, changes in environmental temperature will likely impact the foraging ecology of divers.
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Affiliation(s)
- April Hayward
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Mariela Pajuelo
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Catherine G. Haase
- School of Natural Resources and Environment, University of Florida, Gainesville, FL, USA
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42
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Elliott KH. Measurement of flying and diving metabolic rate in wild animals: Review and recommendations. Comp Biochem Physiol A Mol Integr Physiol 2016; 202:63-77. [PMID: 27264988 DOI: 10.1016/j.cbpa.2016.05.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 05/16/2016] [Accepted: 05/27/2016] [Indexed: 10/21/2022]
Abstract
Animals' abilities to fly long distances and dive to profound depths fascinate earthbound researchers. Due to the difficulty of making direct measurements during flying and diving, many researchers resort to modeling so as to estimate metabolic rate during each of those activities in the wild, but those models can be inaccurate. Fortunately, the miniaturization, customization and commercialization of biologgers has allowed researchers to increasingly follow animals on their journeys, unravel some of their mysteries and test the accuracy of biomechanical models. I provide a review of the measurement of flying and diving metabolic rate in the wild, paying particular attention to mass loss, doubly-labelled water, heart rate and accelerometry. Biologgers can impact animal behavior and influence the very measurements they are designed to make, and I provide seven guidelines for the ethical use of biologgers. If biologgers are properly applied, quantification of metabolic rate across a range of species could produce robust allometric relationships that could then be generally applied. As measuring flying and diving metabolic rate in captivity is difficult, and often not directly translatable to field conditions, I suggest that applying multiple techniques in the field to reinforce one another may be a viable alternative. The coupling of multi-sensor biologgers with biomechanical modeling promises to improve precision in the measurement of flying and diving metabolic rate in wild animals.
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Affiliation(s)
- Kyle H Elliott
- Department of Natural Resource Sciences, McGill University, Ste Anne-de-Bellevue, QC, Canada
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Tyson R, Friedlaender A, Nowacek D. Does optimal foraging theory predict the foraging performance of a large air-breathing marine predator? Anim Behav 2016. [DOI: 10.1016/j.anbehav.2016.03.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Physiological constraints and dive behavior scale in tandem with body mass in auks: A comparative analysis. Comp Biochem Physiol A Mol Integr Physiol 2016; 196:54-60. [PMID: 26952335 DOI: 10.1016/j.cbpa.2016.02.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 02/29/2016] [Accepted: 02/29/2016] [Indexed: 11/22/2022]
Abstract
Many behavioral processes scale with body mass (M) because underlying physiological constraints, such as metabolism, scale with M. A classic example is the maximum duration of dives by breath-hold divers, which scales with M0.25, as predicted from the ratio of oxygen stores (M1.0) to diving oxygen consumption rate (M0.75) - assuming classic scaling relationships for those physiological processes. However, maximum dive duration in some groups of birds does not have a 0.25 scaling exponent. We re-examined the allometric scaling of maximum dive duration in auks to test whether the discrepancy was due to poor data (earlier analyses included data from many different sources possibly leading to bias), phylogeny (earlier analyses did not account for phylogenetic inertia) or physiology (earlier analyses did not analyze physiological parameters alongside behavioral parameters). When we included only data derived from electronic recorders and after accounting for phylogeny, the equation for maximum dive duration was proportional to M0.33. At the same time, myoglobin concentration in small breath-hold divers was proportional to M0.36, implying that muscle oxygen stores were proportional to M1.36, but diving oxygen consumption rate in wing-propelled divers was only proportional to M0.79. Thus, the 99% confidence interval included the exponent of 0.57 predicted from the observed relationships between oxygen stores and consumption rates. In conclusion, auks are not exceptions to the hypothesis that a trade-off between oxygen stores and oxygen utilization drives variation in maximum dive duration. Rather, the scaling exponent for maximum dive duration is higher than expected due to the higher than expected scaling of muscle oxygen stores to body mass.
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Orben RA, Paredes R, Roby DD, Irons DB, Shaffer SA. Body size affects individual winter foraging strategies of thick-billed murres in the Bering Sea. J Anim Ecol 2015; 84:1589-99. [DOI: 10.1111/1365-2656.12410] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 06/05/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Rachael A. Orben
- Department of Ocean Sciences; University of California Santa Cruz; Long Marine Lab; 100 Shaffer Road Santa Cruz CA 95060 USA
- Department of Fisheries and Wildlife; Hatfield Marine Science Center; Oregon State University; Newport OR 97365 USA
| | - Rosana Paredes
- Department of Fisheries and Wildlife; Oregon State University; 104 Nash Hall Corvallis OR 97331-3803 USA
| | - Daniel D. Roby
- U.S. Geological Survey-Oregon Cooperative Fish and Wildlife Research Unit; Oregon State University; 104 Nash Hall Corvallis OR 97331-3803 USA
| | - David B. Irons
- U.S. Fish and Wildlife Service; 1011 East Tudor Road, MS 341 Anchorage AK 99503 USA
| | - Scott A. Shaffer
- Department of Biological Sciences; San Jose State University; One Washington Square San Jose CA 95192-0100 USA
- Long Marine Lab; Institute of Marine Sciences; University of California Santa Cruz; Santa Cruz CA 95060 USA
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Ksepka DT, Werning S, Sclafani M, Boles ZM. Bone histology in extant and fossil penguins (Aves: Sphenisciformes). J Anat 2015; 227:611-30. [PMID: 26360700 DOI: 10.1111/joa.12367] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2015] [Indexed: 11/30/2022] Open
Abstract
Substantial changes in bone histology accompany the secondary adaptation to life in the water. This transition is well documented in several lineages of mammals and non-avian reptiles, but has received relatively little attention in birds. This study presents new observations on the long bone microstructure of penguins, based on histological sections from two extant taxa (Spheniscus and Aptenodytes) and eight fossil specimens belonging to stem lineages (†Palaeospheniscus and several indeterminate Eocene taxa). High bone density in penguins results from compaction of the internal cortical tissues, and thus penguin bones are best considered osteosclerotic rather than pachyostotic. Although the oldest specimens sampled in this study represent stages of penguin evolution that occurred at least 25 million years after the loss of flight, major differences in humeral structure were observed between these Eocene stem taxa and extant taxa. This indicates that the modification of flipper bone microstructure continued long after the initial loss of flight in penguins. It is proposed that two key transitions occurred during the shift from the typical hollow avian humerus to the dense osteosclerotic humerus in penguins. First, a reduction of the medullary cavity occurred due to a decrease in the amount of perimedullary osteoclastic activity. Second, a more solid cortex was achieved by compaction. In extant penguins and †Palaeospheniscus, most of the inner cortex is formed by rapid osteogenesis, resulting an initial latticework of woven-fibered bone. Subsequently, open spaces are filled by slower, centripetal deposition of parallel-fibered bone. Eocene stem penguins formed the initial latticework, but the subsequent round of compaction was less complete, and thus open spaces remained in the adult bone. In contrast to the humerus, hindlimb bones from Eocene stem penguins had smaller medullary cavities and thus higher compactness values compared with extant taxa. Although cortical lines of arrested growth have been observed in extant penguins, none was observed in any of the current sampled specimens. Therefore, it is likely that even these 'giant' penguin taxa completed their growth cycle without a major pause in bone deposition, implying that they did not undergo a prolonged fasting interval before reaching adult size.
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Affiliation(s)
- Daniel T Ksepka
- Bruce Museum, Greenwich, CT, USA.,Smithsonian National Museum of Natural History, Washington, DC, USA
| | - Sarah Werning
- Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Michelle Sclafani
- North Carolina Department of Environment and Natural Resources, Raleigh, NC, USA
| | - Zachary M Boles
- Department of Biology, Drexel University, Philadelphia, PA, USA
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Goldbogen JA, Shadwick RE, Lillie MA, Piscitelli MA, Potvin J, Pyenson ND, Vogl AW. Using morphology to infer physiology: case studies on rorqual whales (Balaenopteridae). CAN J ZOOL 2015. [DOI: 10.1139/cjz-2014-0311] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Whales are important model systems for understanding the physiological and ecological consequences of extreme body size. However, whales are also some of the most difficult animals to study because their large size precludes experimental studies under controlled conditions. Here we review a wide range of morphological studies that enable greater inference of physiological processes. In particular, we focus on baleen whales that exhibit extensive diving and foraging adaptations. Using morphological data, we (i) explore the biomechanics and sensory physiology of lunge-feeding rorqual whales (Balaenopteridae), (ii) determine the effects of scale and diving pressures on the circulatory physiology of fin whales (Balaenoptera physalus (L., 1758)), and (iii) better understand the adaptations of the cetacean respiratory system that facilitate a fully aquatic life history. These studies underscore the value of understanding functional morphology in animals that cannot be studied using traditional laboratory techniques.
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Affiliation(s)
| | - Robert E. Shadwick
- Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Margo A. Lillie
- Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Marina A. Piscitelli
- Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jean Potvin
- Department of Physics, Saint Louis University, St. Louis, MO 63103, USA
| | - Nicholas D. Pyenson
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013-7012, USA
| | - A. Wayne Vogl
- Department of Cellular and Physiological Sciences, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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Differences in foraging ecology align with genetically divergent ecotypes of a highly mobile marine top predator. Oecologia 2015; 179:1041-52. [PMID: 26307593 DOI: 10.1007/s00442-015-3424-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 08/07/2015] [Indexed: 10/23/2022]
Abstract
Foraging differentiation within a species can contribute to restricted gene flow between ecologically different groups, promoting ecological speciation. Galapagos sea lions (Zalophus wollebaeki) show genetic and morphological divergence between the western and central archipelago, possibly as a result of an ecologically mediated contrast in the marine habitat. We use global positioning system (GPS) data, time-depth recordings (TDR), stable isotope and scat data to compare foraging habitat characteristics, diving behaviour and diet composition of Galapagos sea lions from a western and a central colony. We consider both juvenile and adult life stages to assess the potential role of ontogenetic shifts that can be crucial in shaping foraging behaviour and habitat choice for life. We found differences in foraging habitat use, foraging style and diet composition that aligned with genetic differentiation. These differences were consistent between juvenile and adult sea lions from the same colony, overriding age-specific behavioural differences. Our study contributes to an understanding of the complex interaction of ecological condition, plastic behavioural response and genetic make-up of interconnected populations.
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Shero MR, Costa DP, Burns JM. Scaling matters: incorporating body composition into Weddell seal seasonal oxygen store comparisons reveals maintenance of aerobic capacities. J Comp Physiol B 2015; 185:811-24. [PMID: 26164426 DOI: 10.1007/s00360-015-0922-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/24/2015] [Accepted: 07/02/2015] [Indexed: 12/24/2022]
Abstract
Adult Weddell seals (Leptonychotes weddellii) haul-out on the ice in October/November (austral spring) for the breeding season and reduce foraging activities for ~4 months until their molt in the austral fall (January/February). After these periods, animals are at their leanest and resume actively foraging for the austral winter. In mammals, decreased exercise and hypoxia exposure typically lead to decreased production of O2-carrying proteins and muscle wasting, while endurance training increases aerobic potential. To test whether similar effects were present in marine mammals, this study compared the physiology of 53 post-molt female Weddell seals in the austral fall to 47 pre-breeding females during the spring in McMurdo Sound, Antarctica. Once body mass and condition (lipid) were controlled for, there were no seasonal changes in total body oxygen (TBO2) stores. Within each season, hematocrit and hemoglobin values were negatively correlated with animal size, and larger animals had lower mass-specific TBO2 stores. But because larger seals had lower mass-specific metabolic rates, their calculated aerobic dive limit was similar to smaller seals. Indicators of muscular efficiency, myosin heavy chain composition, myoglobin concentrations, and aerobic enzyme activities (citrate synthase and β-hydroxyacyl CoA dehydrogenase) were likewise maintained across the year. The preservation of aerobic capacity is likely critical to foraging capabilities, so that following the molt Weddell seals can rapidly regain body mass at the start of winter foraging. In contrast, muscle lactate dehydrogenase activity, a marker of anaerobic metabolism, exhibited seasonal plasticity in this diving top predator and was lowest after the summer period of reduced activity.
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Affiliation(s)
- Michelle R Shero
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, 99508, USA. .,School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, AK, 99775, USA.
| | - Daniel P Costa
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, 95060, USA
| | - Jennifer M Burns
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, 99508, USA
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Wilson RP, Liebsch N, Gómez-Laich A, Kay WP, Bone A, Hobson VJ, Siebert U. Options for modulating intra-specific competition in colonial pinnipeds: the case of harbour seals (Phoca vitulina) in the Wadden Sea. PeerJ 2015; 3:e957. [PMID: 26082869 PMCID: PMC4465952 DOI: 10.7717/peerj.957] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 04/24/2015] [Indexed: 11/20/2022] Open
Abstract
Colonial pinnipeds may be subject to substantial consumptive competition because they are large, slow-moving central place foragers. We examined possible mechanisms for reducing this competition by examining the diving behaviour of harbour seals (Phoca vitulina) after equipping 34 seals (11 females, 23 males) foraging from three locations; Rømø, Denmark and Lorenzenplate and Helgoland, Germany, in the Wadden Sea area with time-depth recorders. Analysis of 319,021 dives revealed little between-colony variation but appreciable inter-sex differences, with males diving deeper than females, but for shorter periods. Males also had higher vertical descent rates. This result suggests that males may have higher overall swim speeds, which would increase higher oxygen consumption, and may explain the shorter dive durations compared to females. Intersex variation in swim speed alone is predicted to lead to fundamental differences in the time use of three-dimensional space, which may help reduce consumptive competition in harbour seals and other colonial pinnipeds.
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Affiliation(s)
- Rory P Wilson
- Swansea Laboratory for Animal Movement, Biosciences, College of Science, Swansea University , Swansea, Wales , UK ; GEOMAR Helmholtz Centre for Ocean Research, Düsternbrooker , Kiel , Germany
| | - Nikolai Liebsch
- Customized Animal Tracking Solutions , Moffat Beach, QLD , Australia
| | - Agustina Gómez-Laich
- Centro Nacional Patagonico-CONICET , Puerto Madryn (U9120ACD), Chubut , Argentina
| | - William P Kay
- Swansea Laboratory for Animal Movement, Biosciences, College of Science, Swansea University , Swansea, Wales , UK
| | - Andrew Bone
- Swansea Laboratory for Animal Movement, Biosciences, College of Science, Swansea University , Swansea, Wales , UK
| | - Victoria J Hobson
- Swansea Laboratory for Animal Movement, Biosciences, College of Science, Swansea University , Swansea, Wales , UK
| | - Ursula Siebert
- Institute for Terrestrial and Aquatic Wildlife Research, University of Veterinary Medicine Hannover , Büsum , Germany
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