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Mohring B, Öst M, Jaatinen K, Parenteau C, Pallud M, Angelier F. Parenting in a changing environment: A long-term study of prolactin, parental effort and reproductive success in common eiders. Gen Comp Endocrinol 2024; 357:114574. [PMID: 38936675 DOI: 10.1016/j.ygcen.2024.114574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 06/15/2024] [Accepted: 06/19/2024] [Indexed: 06/29/2024]
Abstract
Parental care is regulated by multiple endocrine mechanisms. Among these hormones, prolactin (PRL) is involved in the expression of parental behaviors. Despite the consensus that PRL mediates variation in parental effort with age and body condition, its role in the adjustment of parental effort to fluctuating environmental conditions, including changing predation pressure, still awaits further investigation. To shed light on this knowledge gap, we relied on a long-term monitoring of female common eiders Somateria mollissima (n = 1277 breeding attempts, 2012-2022) incubating under fluctuating predation risk to investigate the link between baseline PRL levels and female minimum age, body condition, clutch size, environmental parameters (predation pressure, climate, nest microhabitat) and hatching success. We predicted that PRL would be higher in older females, those in better condition or incubating larger clutches. We also predicted that females would reduce parental effort when nesting under challenging environmental conditions (high predation pressure or poor climatic conditions), translated into reduced baseline PRL levels. We also explored how variation in PRL levels, female characteristics and environmental parameters were related to hatching success. Following our predictions, PRL levels were positively associated with body condition and female age (before showing a senescent decline in the oldest breeders). However, we did not observe any population-level or individual-level reduction in PRL levels in response to increasing predation pressure. Population-level baseline PRL levels instead increased over the study period, coincident with rising predation threat, but also increasing female body condition and age. While we did not provide evidence for a direct association between baseline PRL levels and predation risk, our results support the idea that elevated baseline PRL levels promote hatching success under internal constraints (in young, inexperienced, breeders or those incubating a large clutch) or constraining environmental conditions (during years of high predation pressure or poor climatic and foraging conditions). Finally, the low repeatability of baseline PRL levels and high interannual variability highlight considerable within-individual flexibility in baseline PRL levels. Further research should explore flexibility in parental effort to changing environmental conditions, focusing on both baseline and stress-induced PRL levels.
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Affiliation(s)
- Bertille Mohring
- Environmental and Marine Biology, Åbo Akademi University, 20500 Turku, Finland; Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS - La Rochelle Université, 79360 Villiers-en-Bois, France; School of Environmental Sciences, University of Liverpool, Liverpool L69 3GP, United Kingdom.
| | - Markus Öst
- Environmental and Marine Biology, Åbo Akademi University, 20500 Turku, Finland; Novia University of Applied Sciences, 10600 Ekenäs, Finland
| | - Kim Jaatinen
- Finnish Environment Institute, 00790 Helsinki, Finland; Tvärminne Zoological Station, University of Helsinki, 10900 Hanko, Finland
| | - Charline Parenteau
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS - La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Marie Pallud
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS - La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Frédéric Angelier
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS - La Rochelle Université, 79360 Villiers-en-Bois, France
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2
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Regan CE, Bogdanova MI, Newell M, Gunn C, Wanless S, Harris MP, Lopez SL, Benninghaus E, Bolton M, Daunt F, Searle KR. Seabirds show foraging site and route fidelity but demonstrate flexibility in response to local information. MOVEMENT ECOLOGY 2024; 12:46. [PMID: 38872225 DOI: 10.1186/s40462-024-00467-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 04/03/2024] [Indexed: 06/15/2024]
Abstract
BACKGROUND Fidelity to a given foraging location or route may be beneficial when environmental conditions are predictable but costly if conditions deteriorate or become unpredictable. Understanding the magnitude of fidelity displayed by different species and the processes that drive or erode it is therefore vital for understanding how fidelity may shape the demographic consequences of anthropogenic change. In particular, understanding the information that individuals may use to adjust their fidelity will facilitate improved predictions of how fidelity may change as environments change and the extent to which it will buffer individuals against such changes. METHODS We used movement data collected during the breeding season across eight years for common guillemots, Atlantic puffins, razorbills, and black-legged kittiwakes breeding on the Isle of May, Scotland to understand: (1) whether foraging site/route fidelity occurred within and between years, (2) whether the degree of fidelity between trips was predicted by personal foraging effort, and (3) whether different individuals made more similar trips when they overlapped in time at the colony prior to departure and/or when out at sea suggesting the use of the same local environmental cues or information on the decisions made by con- and heterospecifics. RESULTS All species exhibited site and route fidelity both within- and between-years, and fidelity between trips in guillemots and razorbills was related to metrics of foraging effort, suggesting they adjust fidelity to their personal foraging experience. We also found evidence that individuals used local environmental cues of prey location or availability and/or information gained by observing conspecifics when choosing foraging routes, particularly in puffins, where trips of individuals that overlapped temporally at the colony or out at sea were more similar. CONCLUSIONS The fidelity shown by these seabird species has the potential to put them at greater risk in the face of environmental change by driving individuals to continue using areas being degraded by anthropogenic pressures. However, our results suggest that individuals show some flexibility in their fidelity, which may promote resilience under environmental change. The benefits of this flexibility are likely to depend on numerous factors, including the rapidity and spatial scale of environmental change and the reliability of the information individuals use to choose foraging sites or routes, thus highlighting the need to better understand how organisms combine cues, prior experience, and other sources of information to make movement decisions.
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Affiliation(s)
- Charlotte E Regan
- UK Centre for Ecology & Hydrology, Bush Estate, EH26 0QB, Penicuik, Midlothian, UK.
| | - Maria I Bogdanova
- UK Centre for Ecology & Hydrology, Bush Estate, EH26 0QB, Penicuik, Midlothian, UK
| | - Mark Newell
- UK Centre for Ecology & Hydrology, Bush Estate, EH26 0QB, Penicuik, Midlothian, UK
| | - Carrie Gunn
- UK Centre for Ecology & Hydrology, Bush Estate, EH26 0QB, Penicuik, Midlothian, UK
| | - Sarah Wanless
- UK Centre for Ecology & Hydrology, Bush Estate, EH26 0QB, Penicuik, Midlothian, UK
| | - Mike P Harris
- UK Centre for Ecology & Hydrology, Bush Estate, EH26 0QB, Penicuik, Midlothian, UK
| | | | - Ella Benninghaus
- UK Centre for Ecology & Hydrology, Bush Estate, EH26 0QB, Penicuik, Midlothian, UK
| | - Mark Bolton
- RSPB Centre for Conservation Science, AB15 6GZ, Aberdeen, UK
| | - Francis Daunt
- UK Centre for Ecology & Hydrology, Bush Estate, EH26 0QB, Penicuik, Midlothian, UK
| | - Kate R Searle
- UK Centre for Ecology & Hydrology, Bush Estate, EH26 0QB, Penicuik, Midlothian, UK
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3
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Minias P, Janiszewski T. Ground nesting in passerine birds: evolution, biogeography and life history correlates. OIKOS 2023. [DOI: 10.1111/oik.09870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- Piotr Minias
- Dept of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, Univ. of Łódź Łódź Poland
| | - Tomasz Janiszewski
- Dept of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, Univ. of Łódź Łódź Poland
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4
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Mohring B, Angelier F, Jaatinen K, Steele B, Lönnberg E, Öst M. Drivers of within- and among-individual variation in risk-taking behaviour during reproduction in a long-lived bird. Proc Biol Sci 2022; 289:20221338. [PMID: 36126681 PMCID: PMC9489283 DOI: 10.1098/rspb.2022.1338] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 08/30/2022] [Indexed: 01/17/2023] Open
Abstract
Plastic and selective mechanisms govern parental investment adjustments to predation threat. We investigated the relative importance of plasticity and selection in risk-taking propensity of incubating female common eiders Somateria mollissima facing unprecedented predation in SW Finland, Baltic Sea. Using a 12-year individual-based dataset, we examined within- and among-individual variation in flight initiation distance (FID), in relation to predation risk, nest detectability, individual traits and reproductive investment (NFID = 1009; Nindividual = 559). We expected females nesting in riskier environments (higher predation risk, lower nest concealment) to mitigate environmentally imposed risk by exhibiting longer FIDs, and females investing more in current reproduction (older, in better condition or laying larger clutches) to display shorter FIDs. The target of predation-adult or offspring-affected the mechanisms adapting risk-taking propensity; females plastically increased their FID under higher adult predation risk, while risk-avoiding breeders were predominant on islands with higher nest predation risk. Risk-taking females selected thicker nest cover, consistent with personality-matching habitat choice. Females plastically attenuated their anti-predator response (shorter FIDs) with advancing age, and females in better body condition were more risk-taking, a result explained by selection processes. Future research should consider predator type when investigating the fitness consequences of risk-taking strategies.
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Affiliation(s)
- Bertille Mohring
- Environmental and Marine Biology, Åbo Akademi University, 20500 Turku, Finland
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS – La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Frédéric Angelier
- Centre d'Etudes Biologiques de Chizé, UMR 7372 CNRS – La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Kim Jaatinen
- Nature and Game Management Trust Finland, 10160 Degerby, Finland
| | - Ben Steele
- School of Arts and Sciences, Colby-Sawyer College, New London, NH 03257, USA
| | | | - Markus Öst
- Environmental and Marine Biology, Åbo Akademi University, 20500 Turku, Finland
- Novia University of Applied Sciences, 10600 Ekenäs, Finland
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5
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Wan X, Holyoak M, Yan C, Le Maho Y, Dirzo R, Krebs CJ, Stenseth NC, Zhang Z. Broad-scale climate variation drives the dynamics of animal populations: a global multi-taxa analysis. Biol Rev Camb Philos Soc 2022; 97:2174-2194. [PMID: 35942895 DOI: 10.1111/brv.12888] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 06/29/2022] [Accepted: 07/01/2022] [Indexed: 01/07/2023]
Abstract
Climate is a major extrinsic factor affecting the population dynamics of many organisms. The Broad-Scale Climate Hypothesis (BSCH) was proposed by Elton to explain the large-scale synchronous population cycles of animals, but the extent of support and whether it differs among taxa and geographical regions is unclear. We reviewed publications examining the relationship between the population dynamics of multiple taxa worldwide and the two most commonly used broad-scale climate indices, El Niño-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO). Our review and synthesis (based on 561 species from 221 papers) reveals that population changes of mammals, birds and insects are strongly affected by major oceanic shifts or irregular oceanic changes, particularly in ENSO- and NAO-influenced regions (Pacific and Atlantic, respectively), providing clear evidence supporting Elton's BSCH. Mammal and insect populations tended to increase during positive ENSO phases. Bird populations tended to increase in positive NAO phases. Some species showed dual associations with both positive and negative phases of the same climate index (ENSO or NAO). These findings indicate that some taxa or regions are more or less vulnerable to climate fluctuations and that some geographical areas show multiple weather effects related to ENSO or NAO phases. Beyond confirming that animal populations are influenced by broad-scale climate variation, we document extensive patterns of variation among taxa and observe that the direct biotic and abiotic mechanisms for these broad-scale climate factors affecting animal populations are very poorly understood. A practical implication of our research is that changes in ENSO or NAO can be used as early signals for pest management and wildlife conservation. We advocate integrative studies at both broad and local scales to unravel the omnipresent effects of climate on animal populations to help address the challenge of conserving biodiversity in this era of accelerated climate change.
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Affiliation(s)
- Xinru Wan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Marcel Holyoak
- Department of Environmental Science and Policy, University of California, California, Davis, 95616, USA
| | - Chuan Yan
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Yvon Le Maho
- Institut Pluridisciplinaire Hubert Curien (IPHC), Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg, Strasbourg, 67000, France.,Centre Scientifique de Monaco, Monaco, 98000, Monaco
| | - Rodolfo Dirzo
- Department of Biology and Woods Institute for the Environment, Stanford University, Stanford, California, 94305, USA
| | - Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Nils Chr Stenseth
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, N-0316, Norway
| | - Zhibin Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
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6
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Byer NW, Reid BN. The emergence of imperfect philopatry and fidelity in spatially and temporally heterogeneous environments. Ecol Modell 2022. [DOI: 10.1016/j.ecolmodel.2022.109968] [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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7
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Mitigating impacts of invasive alien predators on an endangered sea duck amidst high native predation pressure. Oecologia 2022; 198:543-552. [PMID: 35028754 DOI: 10.1007/s00442-021-05101-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 12/18/2021] [Indexed: 10/19/2022]
Abstract
Anthropogenically introduced invasive species represent a major threat to global biodiversity by causing population declines and extinctions of native species. The negative impacts of introduced predators are well documented, yet a fundamental knowledge gap exists regarding the efficiency of potential mitigation methods to restore the ecosystem. Other understudied aspects concern prey behavioural antipredator responses and the historical context of native predator-prey interactions, which may moderate invasion impacts on native prey. Invasion impacts of American mink (Neovison vison) and raccoon dog (Nyctereutes procyonoides) into the Baltic Sea archipelago are poorly understood, and the efficiency of removal efforts as a means to alleviate depredation pressure on native prey is debated. Here, we examine the effectiveness of invasive predator removal on ground-nesting female common eider (Somateria mollissima) mortality, breeding success and breeding propensity over a 9-year period, while controlling for predation risk imposed by the main native predator, the white-tailed eagle (Haliaeetus albicilla). Our results clearly show that intensified removal of American minks and raccoon dogs decreased the number of female eiders killed during nesting, while improving both nesting success and breeding propensity. Such obvious positive effects of invasive predator removal are particularly noteworthy against the backdrop of a soaring eagle population, indicating that the impacts of invasives may become accentuated when native predators differ taxonomically and by hunting mode. This study shows that invasive alien predator removal is an effective conservation measure clearly aiding native fauna even under severe native predation pressure. Such cost-effective conservation actions call for governmental deployment across large areas.
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8
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Öst M, Lehikoinen A, Jaatinen K. Top–down effects override climate forcing on reproductive success in a declining sea duck. OIKOS 2021. [DOI: 10.1111/oik.08762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Markus Öst
- Environmental and Marine Biology, Biocity, Åbo Akademi Univ. Turku Finland
- Novia Univ. of Applied Sciences Ekenäs Finland
| | - Aleksi Lehikoinen
- Finnish Museum of Natural History, Univ. of Helsinki Helsinki Finland
| | - Kim Jaatinen
- Nature and Game Management Trust Finland Degerby Finland
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9
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Enhancing the ecological realism of evolutionary mismatch theory. Trends Ecol Evol 2021; 37:233-245. [PMID: 34802715 DOI: 10.1016/j.tree.2021.10.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 11/23/2022]
Abstract
Following rapid environmental change, why do some animals thrive, while others struggle? We present an expanded, cue-response framework for predicting variation in behavioral responses to novel situations. We show how signal detection theory can be used when individuals have three behavioral options (approach, avoid, or ignore). Based on this theory, we outline predictions about which animals are more likely to make mistakes around novel conditions (i.e., fall for a trap or fail to use an undervalued resource) and the intensity of that mismatch (i.e., severe versus moderate). Explicitly considering three options provides a more holistic perspective and allows us to distinguish between severe and moderate traps, which could guide management strategies in a changing world.
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10
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Van de Vuurst P, Moore SA, Isaac EJ, Chenaux-Ibrahim Y, Wolf TM, Escobar LE. Current Zoology Reconstructing landscapes of ungulate parturition and predation using vegetation phenology. Curr Zool 2021; 68:275-283. [PMID: 35592351 PMCID: PMC9113264 DOI: 10.1093/cz/zoab058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 07/21/2021] [Indexed: 11/13/2022] Open
Abstract
Abstract
Enhanced vegetation index (EVI) data can be used to identify and define the space in which ungulates practice parturition and encounter predation. This study explores the use of EVI data to identify landscapes linked to ungulate parturition and predation events across space, time, and environmental conditions. As a case study, we used the moose population (Alces alces) of northern Minnesota in the USA. Using remotely sensed EVI data rasters and global positioning system collar data, we quantified how vegetation phenology and moose movement shaped the births and predation of 52 moose calves from 2013 to 2020 on or adjacent to the Grand Portage Indian Reservation. The known sources of predation were American black bears (Ursus americanus, n = 22) and gray wolves (Canis lupus, n = 28). Satellite-derived data summarizing seasonal landscape features at the local level revealed that landscape heterogeneity use by moose can help to quantitatively identify landscapes of parturition and predation in space and time across large areas. Vegetation phenology proved to be differentiable between adult moose ranges, sites of cow parturition, and sites of calf predation. Landscape characteristics of each moose group were consistent and tractable based on environment, suggesting that sites of parturition and predation of moose are predictable in space and time. It is possible that moose selected specific landscapes for parturition despite risk of increased predation of their calves, which could be an example of an "ecological trap." This analytical framework can be employed to identify areas for future ungulate research on the impacts of landscape on parturition and predation dynamics.
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Affiliation(s)
- Paige Van de Vuurst
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA 24061, USA
| | - Seth A Moore
- Department of Biology and Environment, Grand Portage Band of Lake Superior Chippewa, Grand Portage, MN 55605, USA
| | - Edmund J Isaac
- Department of Biology and Environment, Grand Portage Band of Lake Superior Chippewa, Grand Portage, MN 55605, USA
| | - Yvette Chenaux-Ibrahim
- Department of Biology and Environment, Grand Portage Band of Lake Superior Chippewa, Grand Portage, MN 55605, USA
| | - Tiffany M Wolf
- Veterinary Population Medicine, University of Minnesota, St Paul, MN 55108, USA
| | - Luis E Escobar
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, VA 24061, USA
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11
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Mohring B, Angelier F, Jaatinen K, Parenteau C, Öst M. Parental Investment Under Predation Threat in Incubating Common Eiders (Somateria mollissima): A Hormonal Perspective. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.637561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Predation risk affects the costs and benefits of prey life-history decisions. Predation threat is often higher during reproduction, especially in conspicuous colonial breeders. Therefore, predation risk may increase the survival cost of breeding, and reduce parental investment. The impact of predation risk on avian parental investment decisions may be hormonally mediated by prolactin and corticosterone, making them ideal tools for studying the trade-offs involved. Prolactin is thought to promote parental care and commitment in birds. Corticosterone is involved in allostasis and may either mediate reduced parental investment (corticosterone-fitness hypothesis), or promote parental investment through a reallocation of resources (corticosterone-adaptation hypothesis). Here, we used these hormonal proxies of incubation commitment to examine the impact of predation risk on reproduction in common eiders (Somateria mollissima) breeding in the Baltic Sea. This eider population is subject to high but spatially and temporally variable predation pressure on adults (mainly by the white-tailed eagle Haliaeetus albicilla and introduced mammalian predators) and nests (by the adult predators and exclusive egg predators such as hooded crows Corvus cornix). We investigated baseline hormonal levels and hatching success as a function of individual quality attributes (breeding experience, female and duckling body condition), reproductive investment (clutch weight), and predation risk. We expected individuals nesting in riskier environments (i.e., on islands where predation on adults or nests is higher, or in less concealed nests) to reduce their parental investment in incubation, reflected in lower baseline prolactin levels and either higher (corticosterone-fitness hypothesis) or lower (corticosterone-adaptation hypothesis) baseline corticosterone levels. Contrary to our predictions, prolactin levels showed a positive correlation with nest predation risk. The unexpected positive relationship could result from the selective disappearance of low-quality females (presumably having low prolactin levels) from risky sites. Supporting this notion, female body condition and hatching success were positively correlated with predation risk on females, and baseline prolactin concentrations were positively correlated with duckling body condition, a proxy of maternal quality. In line with the corticosterone-adaptation hypothesis, baseline corticosterone levels increased with reproductive investment, and were negatively associated with nest predation risk. Hatching success was lower on islands where nest predation risk was higher, consistent with the idea of reduced reproductive investment under increased threat. Long-term individual-based studies are now needed to distinguish selection processes occurring at the population scale from individually plastic parental investment in relation to individual quality and variable predation risk.
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12
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Morelli F, Laursen K, Svitok M, Benedetti Y, Møller AP. Eiders, nutrients and eagles: Bottom-up and top-down population dynamics in a marine bird. J Anim Ecol 2021; 90:1844-1853. [PMID: 33844857 DOI: 10.1111/1365-2656.13498] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/31/2021] [Indexed: 12/01/2022]
Abstract
The main objective of this long-term study (1978-2016) was to find the underlying factors behind the declining trends of eider Somateria mollissima in the Baltic/Wadden Sea. Specifically, we aimed at quantifying the bottom-up effect of nutrients, through mussel stocks, on reproduction and abundance of eider, and the top-down effects caused by white-tailed eagle Haliaeetus albicilla predation. Bottom-up effects increase marine primary productivity with subsequent effects on food availability for a major mussel predator. Top-down effects may also regulate eider populations because during incubation female eiders are vulnerable to predation by eagles. Our structural equation modelling explained a large percentage of the variance in eider abundance. We conclude that the Baltic/Wadden Sea eider population was regulated directly by white-tailed sea eagle predation on incubating females and indirectly by the amount of nutrients in seawater affecting both mussel stocks and the breeding success of eiders, reflecting density dependence. These findings may explain the decreasing trend in the Baltic/Wadden Sea eider population during the last decades as an additive effect of top-down and bottom-up factors, and likely as an interaction between them.
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Affiliation(s)
- Federico Morelli
- Faculty of Environmental Sciences, Community Ecology & Conservation, Czech University of Life Sciences Prague, Prague 6, Czech Republic.,Institute of Biological Sciences, University of Zielona Góra, Zielona Góra, Poland
| | - Karsten Laursen
- Institute of Bioscience, Aarhus University, Grenåvej 14, Denmark
| | - Marek Svitok
- Department of Biology and General Ecology, Faculty of Ecology and Environmental Sciences, Technical University in Zvolen, Zvolen, Slovakia.,Department of Ecosystem Biology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Yanina Benedetti
- Faculty of Environmental Sciences, Community Ecology & Conservation, Czech University of Life Sciences Prague, Prague 6, Czech Republic
| | - Anders Pape Møller
- Laboratoire d'Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Saclay, Orsay Cedex, France.,Ministry of Education Key Laboratory for Biodiversity and Ecological Engineering, College of Life Sciences, Beijing Normal University, Beijing, China
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13
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Ekblad C, Tikkanen H, Sulkava S, Laaksonen T. Diet and breeding habitat preferences of White-tailed Eagles in a northern inland environment. Polar Biol 2020. [DOI: 10.1007/s00300-020-02769-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AbstractMany apex predator populations are recolonizing old areas and dispersing to new ones, with potential consequences for their prey species and for livestock. An increasing population of the White-tailed Eagle (Haliaeetus albicilla) has settled north of the Arctic Circle in northern Finland, mainly at two big water reservoirs but also in areas with mainly terrestrial habitat. We examined nesting habitat preferences and prey use of White-tailed Eagles in this environment, where reindeer husbandry is a traditional livelihood and concerns are rising that the growing White-tailed Eagle population poses a threat to reindeer calves. Lakes, peat bogs, and marshlands were preferred habitats in the nesting territories. Fish constituted 64.3% of the identified prey items, with birds accounting for 28.5% and mammals 7.2%. The nesting territory habitat within a 10 km radius and the latitude influenced the prey composition at both the group and species level. The occurrence of reindeer calves as prey increased with latitude but was not associated with any habitat. Knowledge of the diet and territory preferences can be used to predict future dispersal and local prey use of this species. Nesting White-tailed Eagles do not seem to pose a threat to traditional reindeer herding, but further research is needed regarding non-breeding sub-adults and whether the White-tailed Eagles actually kill reindeer calves or simply exploit their carcasses.
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14
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Tjørnløv RS, Ens BJ, Öst M, Jaatinen K, Karell P, Larsson R, Christensen TK, Frederiksen M. Drivers of Spatiotemporal Variation in Survival in a Flyway Population: A Multi-Colony Study. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.566154] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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15
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Öst M, Noreikiene K, Angelier F, Jaatinen K. Sex-specific effects of the in ovo environment on early-life phenotypes in eiders. Oecologia 2019; 192:43-54. [PMID: 31786666 PMCID: PMC6974505 DOI: 10.1007/s00442-019-04569-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 11/25/2019] [Indexed: 12/14/2022]
Abstract
Maternal effects affect offspring phenotype and fitness. However, the roles of offspring sex-specific sensitivity to maternal glucocorticoids and sex-biased maternal investment remain unclear. It is also uncertain whether telomere length (a marker associated with lifespan) depends on early growth in a sex-specific manner. We assessed whether maternal traits including corticosterone (CORT; the main avian glucocorticoid) and in ovo growth rate are sex-specifically related to offspring CORT exposure, relative telomere length (RTL) and body condition in eiders (Somateria mollissima). We measured feather CORT (fCORT), RTL and body condition of newly hatched ducklings, and growth rate in ovo was expressed as tarsus length at hatching per incubation duration. Maternal traits included baseline plasma CORT, RTL, body condition and breeding experience. We found that fCORT was negatively associated with growth rate in daughters, while it showed a positive association in sons. Lower offspring fCORT was associated with higher maternal baseline plasma CORT, and fCORT was higher in larger clutches and in those hatching later. The RTL of daughters was negatively associated with maternal RTL, whereas that of males was nearly independent of maternal RTL. Higher fCORT in ovo was associated with longer RTL at hatching in both sexes. Duckling body condition was mainly explained by egg weight, and sons had a slightly lower body condition. Our correlational results suggest that maternal effects may have heterogeneous and even diametrically opposed effects between the sexes during early development. Our findings also challenge the view that prenatal CORT exposure is invariably associated with shorter telomeres.
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Affiliation(s)
- Markus Öst
- Environmental and Marine Biology, Åbo Akademi University, Turku, Finland. .,Novia University of Applied Sciences, Ekenäs, Finland.
| | - Kristina Noreikiene
- Chair of Aquaculture, Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Kreutzwaldi tn. 46, Tartu, Estonia
| | - Frederic Angelier
- Centre d'Etudes Biologiques de Chizé, CNRS, La Rochelle Université, UMR 7372, Villiers en Bois, France
| | - Kim Jaatinen
- Nature and Game Management Trust Finland, Degerby, Finland
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16
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Tjørnløv RS, Pradel R, Choquet R, Christensen TK, Frederiksen M. Consequences of past and present harvest management in a declining flyway population of common eiders Somateria mollissima. Ecol Evol 2019; 9:12515-12530. [PMID: 31788194 PMCID: PMC6875579 DOI: 10.1002/ece3.5707] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 09/02/2019] [Accepted: 09/06/2019] [Indexed: 01/20/2023] Open
Abstract
Harvested species population dynamics are shaped by the relative contribution of natural and harvest mortality. Natural mortality is usually not under management control, so managers must continuously adjust harvest rates to prevent overexploitation. Ideally, this requires regular assessment of the contribution of harvest to total mortality and how this affects population dynamics.To assess the impact of hunting mortality on the dynamics of the rapidly declining Baltic/Wadden Sea population of common eiders Somateria mollissima, we first estimated vital rates of ten study colonies over the period 1970-2015. By means of a multi-event capture-recovery model, we then used the cause of death of recovered individuals to estimate proportions of adult females that died due to hunting or other causes. Finally, we adopted a stochastic matrix population modeling approach based on simulations to investigate the effect of past and present harvest regulations on changes in flyway population size and composition.Results showed that even the complete ban on shooting females implemented in 2014 in Denmark, where most hunting takes place, was not enough to stop the population decline given current levels of natural female mortality. Despite continued hunting of males, our predictions suggest that the proportion of females will continue to decline unless natural mortality of the females is reduced.Although levels of natural mortality must decrease to halt the decline of this population, we advocate that the current hunting ban on females is maintained while further investigations of factors causing increased levels of natural mortality among females are undertaken. Synthesis and applications. At the flyway scale, continuous and accurate estimates of vital rates and the relative contribution of harvest versus other mortality causes are increasingly important as the population effect of adjusting harvest rates is most effectively evaluated within a model-based adaptive management framework.
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Affiliation(s)
| | - Roger Pradel
- CEFECNRSUniv MontpellierUniv Paul Valéry Montpellier 3EPHEIRDMontpellierFrance
| | - Rémi Choquet
- CEFECNRSUniv MontpellierUniv Paul Valéry Montpellier 3EPHEIRDMontpellierFrance
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17
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Jaatinen K, Møller AP, Öst M. Annual variation in predation risk is related to the direction of selection for brain size in the wild. Sci Rep 2019; 9:11847. [PMID: 31413345 PMCID: PMC6694153 DOI: 10.1038/s41598-019-48153-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/22/2019] [Indexed: 11/09/2022] Open
Abstract
The direction of predator-mediated selection on brain size is debated. However, the speed and the accuracy of performing a task cannot be simultaneously maximized. Large-brained individuals may be predisposed to accurate but slow decision-making, beneficial under high predation risk, but costly under low risk. This creates the possibility of temporally fluctuating selection on brain size depending on overall predation risk. We test this idea in nesting wild eider females (Somateria mollissima), in which head volume is tightly linked to brain mass (r2 = 0.73). We determined how female relative head volume relates to survival, and characterized the seasonal timing of predation. Previous work suggests that relatively large-brained and small-brained females make slow versus fast nest-site decisions, respectively, and that predation events occur seasonally earlier when predation is severe. Large-brained, late-breeding females may therefore have higher survival during high-predation years, but lower survival during safe years, assuming that predation disproportionately affects late breeders in such years. Relatively large-headed females outsurvived smaller-headed females during dangerous years, whereas the opposite was true in safer years. Predation events occurred relatively later during safe years. Fluctuations in the direction of survival selection on relative brain size may therefore arise due to brain-size dependent breeding phenology.
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Affiliation(s)
- Kim Jaatinen
- Nature and Game Management Trust Finland, Degerbyvägen 176, FI-10160, Degerby, Finland.
| | - Anders P Møller
- Ecologie Systématique Evolution, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, F-91405, Orsay Cedex, France
| | - Markus Öst
- Environmental and Marine Biology, Faculty of Science and Engineering, Åbo Akademi University, Artillerigatan 6, FI-20520, Turku, Finland
- Novia University of Applied Sciences, Raseborgsvägen 9, FI-10600, Ekenäs, Finland
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18
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Greenwell CN, Calver MC, Loneragan NR. Cat Gets Its Tern: A Case Study of Predation on a Threatened Coastal Seabird. Animals (Basel) 2019; 9:ani9070445. [PMID: 31315191 PMCID: PMC6681120 DOI: 10.3390/ani9070445] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 06/26/2019] [Accepted: 07/09/2019] [Indexed: 12/16/2022] Open
Abstract
Domestic cats have a cosmopolitan distribution, commonly residing in urban, suburban and peri-urban environments that are also critical for biodiversity conservation. This study describes the impact of a desexed, free-roaming cat on the behavior of a threatened coastal seabird, the Australian Fairy Tern, Sternula nereis nereis, in Mandurah, south-western Australia. Wildlife cameras and direct observations of cat incursions into the tern colony at night, decapitated carcasses of adult terns, dead, injured or missing tern chicks, and cat tracks and scats around the colony provided strong evidence of cat predation, which led to an initial change in nesting behavior and, ultimately, colony abandonment and the reproductive failure of 111 nests. The death of six breeding terns from the population was a considerable loss for this threatened species and had the potential to limit population growth. This study highlights the significant negative impacts of free-roaming cats on wildlife and the need for monitoring and controlling cats at sites managed for species conservation. It also provides strong evidence against the practice of trap-neuter-release programs and demonstrates that desexed cats can continue to negatively impact wildlife post-release directly through predation, but also indirectly through fundamental changes in prey behavior and a reduction in parental care.
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Affiliation(s)
- Claire N Greenwell
- Environmental and Conservation Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia.
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia.
| | - Michael C Calver
- Environmental and Conservation Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia
| | - Neil R Loneragan
- Environmental and Conservation Sciences, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, 90 South Street, Murdoch, Western Australia 6150, Australia
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19
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Imlay TL, Nickerson D, Horn AG. Temperature and breeding success for Cliff Swallows (Petrochelidon pyrrhonota) nesting on man-made structures: ecological traps? CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0224] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
When an environmental cue that previously signaled a suitable habitat leads an animal to use an unsuitable site, individual fitness can decrease, ultimately leading to population declines. Such “ecological traps” may be particularly likely for birds that use human infrastructure for nesting. Here we tested whether high nest temperatures and the physical properties of barns are associated with lower breeding success for a declining population of Cliff Swallows (Petrochelidon pyrrhonota (Vieillot, 1817)). We monitored nests under barn eaves below wood and metal roofs to determine nestling survival and mass, and recorded temperature under barn eaves, to relate ambient temperature to eave temperature. We found that eave temperature increased with ambient temperatures and was higher at high temperatures and lower at cool temperatures under metal roofs than wood roofs. Nestling survival was lower during periods with higher ambient temperatures, and both survival and mass were lower under metal roofs. Our findings suggest that barn eaves, especially those with metal roofs, may be an ecological trap for Cliff Swallows, where a seemingly suitable nesting site early in the breeding season results in low breeding success. Furthermore, warming temperatures may lead to ecological traps for other bird species, particularly those nesting in man-made structures.
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Affiliation(s)
- Tara L. Imlay
- Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Donavon Nickerson
- Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Andrew G. Horn
- Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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20
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Nest predation by raccoon dog Nyctereutes procyonoides in the archipelago of northern Sweden. Biol Invasions 2018. [DOI: 10.1007/s10530-018-1855-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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21
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Hale R, Coleman R, Sievers M, Brown TR, Swearer SE. Using conservation behavior to manage ecological traps for a threatened freshwater fish. Ecosphere 2018. [DOI: 10.1002/ecs2.2381] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Robin Hale
- School of BioSciences University of Melbourne Parkville Victoria 3010 Australia
| | - Rhys Coleman
- Melbourne Water Corporation Docklands Victoria 3008 Australia
- School of Ecosystem and Forest Sciences University of Melbourne Parkville Victoria 3008 Australia
| | - Michael Sievers
- School of BioSciences University of Melbourne Parkville Victoria 3010 Australia
- School of Ecosystem and Forest Sciences University of Melbourne Parkville Victoria 3008 Australia
| | - Timothy R. Brown
- School of BioSciences University of Melbourne Parkville Victoria 3010 Australia
| | - Stephen E. Swearer
- School of BioSciences University of Melbourne Parkville Victoria 3010 Australia
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22
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To breed or not to breed: drivers of intermittent breeding in a seabird under increasing predation risk and male bias. Oecologia 2018; 188:129-138. [DOI: 10.1007/s00442-018-4176-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 05/25/2018] [Indexed: 10/14/2022]
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23
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Ramula S, Öst M, Lindén A, Karell P, Kilpi M. Increased male bias in eider ducks can be explained by sex-specific survival of prime-age breeders. PLoS One 2018; 13:e0195415. [PMID: 29634733 PMCID: PMC5892891 DOI: 10.1371/journal.pone.0195415] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 03/21/2018] [Indexed: 12/02/2022] Open
Abstract
In contrast to theoretical predictions of even adult sex ratios, males are dominating in many bird populations. Such bias among adults may be critical to population growth and viability. Nevertheless, demographic mechanisms for biased adult sex ratios are still poorly understood. Here, we examined potential demographic mechanisms for the recent dramatic shift from a slight female bias among adult eider ducks (Somateria mollissima) to a male bias (about 65% males) in the Baltic Sea, where the species is currently declining. We analysed a nine-year dataset on offspring sex ratio at hatching based on molecularly sexed ducklings of individually known mothers. Moreover, using demographic data from long-term individual-based capture-recapture records, we investigated how sex-specific survival at different ages after fledgling can modify the adult sex ratio. More specifically, we constructed a stochastic two-sex matrix population model and simulated scenarios of different survival probabilities for males and females. We found that sex ratio at hatching was slightly female-biased (52.8%) and therefore unlikely to explain the observed male bias among adult birds. Our stochastic simulations with higher survival for males than for females revealed that despite a slight female bias at hatching, study populations shifted to a male-biased adult sex ratio (> 60% males) in a few decades. This shift was driven by prime reproductive-age individuals (≥5-year-old), with sex-specific survival of younger age classes playing a minor role. Hence, different age classes contributed disproportionally to population dynamics. We argue that an alternative explanation for the observed male dominance among adults–sex-biased dispersal–can be considered redundant and is unlikely, given the ecology of the species. The present study highlights the importance of considering population structure and age-specific vital rates when assessing population dynamics and management targets.
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Affiliation(s)
- Satu Ramula
- Department of Biology, University of Turku, Turku, Finland
| | - Markus Öst
- Bioeconomy Research Team, Novia University of Applied Sciences, Ekenäs, Finland.,Environmental and Marine Biology, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Andreas Lindén
- Bioeconomy Research Team, Novia University of Applied Sciences, Ekenäs, Finland
| | - Patrik Karell
- Bioeconomy Research Team, Novia University of Applied Sciences, Ekenäs, Finland
| | - Mikael Kilpi
- Bioeconomy Research Team, Novia University of Applied Sciences, Ekenäs, Finland
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24
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Carreras C, Pascual M, Tomás J, Marco A, Hochscheid S, Castillo JJ, Gozalbes P, Parga M, Piovano S, Cardona L. Sporadic nesting reveals long distance colonisation in the philopatric loggerhead sea turtle (Caretta caretta). Sci Rep 2018; 8:1435. [PMID: 29362421 PMCID: PMC5780500 DOI: 10.1038/s41598-018-19887-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 01/10/2018] [Indexed: 11/08/2022] Open
Abstract
The colonisation of new suitable habitats is crucial for species survival at evolutionary scale under changing environmental conditions. However, colonisation potential may be limited by philopatry that facilitates exploiting successful habitats across generations. We examine the mechanisms of long distance dispersal of the philopatric loggerhead sea turtle (Caretta caretta) by analysing 40 sporadic nesting events in the western Mediterranean. The analysis of a fragment of the mitochondrial DNA and 7 microsatellites of 121 samples from 18 of these nesting events revealed that these nests were colonising events associated with juveniles from distant populations feeding in nearby foraging grounds. Considering the temperature-dependent sex determination of the species, we simulated the effect of the incubation temperature and propagule pressure on a potential colonisation scenario. Our results indicated that colonisation will succeed if warm temperature conditions, already existing in some of the beaches in the area, extend to the whole western Mediterranean. We hypothesize that the sporadic nesting events in developmental foraging grounds may be a mechanism to overcome philopatry limitations thus increasing the dispersal capabilities of the species and the adaptability to changing environments. Sporadic nesting in the western Mediterranean can be viewed as potential new populations in a scenario of rising temperatures.
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Affiliation(s)
- Carlos Carreras
- Department of Genetics, Microbiology and Statistics and IRBio, University of Barcelona, Av.Diagonal 643, E-08028, Barcelona, Spain.
- Centre for Ecology and Conservation, University of Exeter, Cornwall Campus, Penryn, TR10 9EZ, UK.
| | - Marta Pascual
- Department of Genetics, Microbiology and Statistics and IRBio, University of Barcelona, Av.Diagonal 643, E-08028, Barcelona, Spain
| | - Jesús Tomás
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Apdo. 22085, E-46071, Valencia, Spain
| | - Adolfo Marco
- Estación Biológica de Doñana, CSIC, c/ Américo Vespucio s/n, E-41092, Sevilla, Spain
| | - Sandra Hochscheid
- Marine Turtle Research Centre, Department RIMAR, Stazione Zoologica Anton Dohrn, Via Nuova Macello, 80055, Portici, Italy
| | - Juan José Castillo
- CREMA (Centro de Recuperación de Especies Marinas Amenazadas), Aula del Mar de Málaga-Consejería de Medio Ambiente de la Junta de Andalucía, c/Pacífico 80, E-29004, Málaga, Spain
| | - Patricia Gozalbes
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Apdo. 22085, E-46071, Valencia, Spain
| | - Mariluz Parga
- Submon Marine Conservation, Rabassa 49, E-08024, Barcelona, Spain
- Marine Animal Rescue Center (CRAM), Passeig de la Platja 28-30, E-08820, El Prat de Llobregat, Spain
| | - Susanna Piovano
- Dipartimento di Biologia Animale e dell'Uomo, University of Torino, Via Accademia Albertina 13, 10123, Turin, Italy
- School of Marine Studies, The University of the South Pacific, Laucala Campus, Prive Mail Bag, Suva, Fiji
| | - Luis Cardona
- Department of Evolutionary Biology, Ecology and Environmental Sciences and IRBIo, University of Barcelona, Avda. Diagonal 643, E-08028, Barcelona, Spain
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25
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Noreikiene K, Öst M, Seltmann M, Boner W, Monaghan P, Jaatinen K. Nest cover and faecal glucocorticoid metabolites are linked to hatching success and telomere length in breeding Common Eiders (Somateria mollissima). CAN J ZOOL 2017. [DOI: 10.1139/cjz-2016-0242] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Habitat-associated crypsis may affect perceived predation vulnerability, selecting for different predator avoidance strategies. Glucocorticoids could mediate the adjustment of escape responses to the extent of crypsis, introducing an overlooked source of variation in glucocorticoid–fitness relationships. However, prolonged exposure to elevated glucocorticoids may be costly, leading to accelerated telomere loss and, consequently, senescence. Here, we examined how nest cover and immunoreactive faecal glucocorticoid metabolite (fGCM) levels are linked to hatching success and telomere length in breeding female Common Eiders (Somateria mollissima (L., 1758)). We hypothesized that the degree of nest crypsis, reflecting differences in perceived predation risk, would moderate the relationship between reproductive success and fGCM levels. We also expected that telomere length would be shorter in birds with higher glucocorticoid concentration. Results showed that individuals with high fGCM levels had higher hatching success in nests with low cover, while low fGCM levels were more successful in well-concealed nests. We found that shorter telomeres were associated with high fGCM in nesting sites offering little cover and with low fGCM in well-concealed ones. This study provides the first evidence of habitat-dependent moderation of the relationships between stress physiology, telomere length and hatching success.
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Affiliation(s)
- K. Noreikiene
- Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki, P.O. Box 65, FI-00014 Helsinki, Finland
| | - M. Öst
- Environmental and Marine Biology, Faculty of Science and Engineering, Åbo Akademi University, Artillerigatan 6, FI-20520 Turku, Finland; Novia University of Applied Sciences, Raseborgsvägen 9, FI-10600 Ekenäs, Finland
| | - M.W. Seltmann
- Department of Biology, University of Turku, FI-20014 Turku, Finland
| | - W. Boner
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - P. Monaghan
- Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, Graham Kerr Building, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - K. Jaatinen
- Tvärminne Zoological Station, University of Helsinki, J.A. Palménin tie 260, 10900 Hanko, Finland
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26
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Abstract
Ecological traps, which occur when animals mistakenly prefer habitats where their fitness is lower than in other available habitats following rapid environmental change, have important conservation and management implications. Empirical research has focused largely on assessing the behavioural effects of traps, by studying a small number of geographically close habitat patches. Traps, however, have also been defined in terms of their population-level effects (i.e. as preferred habitats of sufficiently low quality to cause population declines), and this is the scale most relevant for management. We systematically review the ecological traps literature to (i) describe the geographical and taxonomic distribution of efforts to study traps, (ii) examine how different traps vary in the strength of their effects on preference and fitness, (iii) evaluate the robustness of methods being used to identify traps, and (iv) determine whether the information required to assess the population-level consequences of traps has been considered. We use our results to discuss key knowledge gaps, propose improved methods to study traps, and highlight fruitful avenues for future research.
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Affiliation(s)
- Robin Hale
- School of BioSciences, University of Melbourne, Parkville 3010, Australia
| | - Stephen E Swearer
- School of BioSciences, University of Melbourne, Parkville 3010, Australia
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27
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Morosinotto C, Villers A, Thomson RL, Varjonen R, Korpimäki E. Competitors and predators alter settlement patterns and reproductive success of an intraguild prey. ECOL MONOGR 2017. [DOI: 10.1002/ecm.1238] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Chiara Morosinotto
- Department of Biology; Section of Ecology; University of Turku; FI-20014 Turku Finland
| | - Alexandre Villers
- Department of Biology; Section of Ecology; University of Turku; FI-20014 Turku Finland
- Centre d'Etudes Biologiques de Chizé; UMR7372; CNRS - Université de la Rochelle; 79360 Villiers en Bois France
| | - Robert L. Thomson
- Department of Biology; Section of Ecology; University of Turku; FI-20014 Turku Finland
- FitzPatrick Institute of African Ornithology; DST-NRF Centre of Excellence; University of Cape Town; Rondebosch 7701 Cape Town South Africa
| | - Rauno Varjonen
- Department of Biology; Section of Ecology; University of Turku; FI-20014 Turku Finland
| | - Erkki Korpimäki
- Department of Biology; Section of Ecology; University of Turku; FI-20014 Turku Finland
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28
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Andersson M. Helping Relatives Survive and Reproduce: Inclusive Fitness and Reproductive Value in Brood Parasitism. Am Nat 2016; 189:138-152. [PMID: 28107054 DOI: 10.1086/689991] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Costly help can raise a relative's reproduction, survival, and reproductive value and increase the inclusive fitness of the donor of help. Donor fitness is explored here in conspecific brood parasitism. In this alternative reproductive tactic, some females, "parasites," lay eggs in nests of other females of the same species, "hosts," suppliers of help that alone take care of the offspring. Modeling shows that hosts can gain inclusive fitness if parasitized by relatives whose reproduction or survival is thereby increased. These predictions are explored in waterfowl with frequent brood parasitism, female-biased philopatry, and neighbor relatedness. Approximate estimates based on waterfowl reproductive and life-history data show that host inclusive-fitness gain is often possible with related parasites. The largest gains can be achieved through increased reproduction, but gain is also possible through higher survival of parasites that avoid increased predation and other risks of nesting. Inclusive fitness depends on parasite reproductive value and can be highest for a host parasitized by her mother and for old, senescent hosts with low fecundity, helping young related parasites. These results and observed levels of host-parasite relatedness suggest that being "parasitized" in waterfowl is sometimes neutral or even advantageous because of inclusive-fitness benefits, contributing to evolution of frequent conspecific brood parasitism in this group.
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29
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Milton GR, Iverson SA, Smith PA, Tomlik MD, Parsons GJ, Mallory ML. Sex-specific survival of adult common eiders in Nova Scotia, Canada. J Wildl Manage 2016. [DOI: 10.1002/jwmg.21135] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- G. Randy Milton
- Department of Natural Resources; 136 Exhibition Street Kentville NS B4N 4E5 Canada
| | - Samuel A. Iverson
- Canadian Wildlife Service, Environment Canada; 335 River Road Ottawa ON K1A 0H3 Canada
| | - Paul A. Smith
- Wildlife Research Division; Environment Canada; National Wildlife Research Centre, Raven Road; Carleton University; Ottawa ON K1A 0H3 Canada
| | - Molly D. Tomlik
- Department of Biology; Acadia University; Wolfville NS B4P 2R6 Canada
| | - Glen J. Parsons
- Department of Natural Resources; 136 Exhibition Street Kentville NS B4N 4E5 Canada
| | - Mark L. Mallory
- Department of Biology; Acadia University; Wolfville NS B4P 2R6 Canada
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30
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Jaatinen K, Öst M, Hobson KA. State-dependent capital and income breeding: a novel approach to evaluating individual strategies with stable isotopes. Front Zool 2016; 13:24. [PMID: 27284285 PMCID: PMC4899916 DOI: 10.1186/s12983-016-0157-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/30/2016] [Indexed: 11/23/2022] Open
Abstract
Background Species-specific strategies for financing the costs of reproduction are well understood, forming a continuum ranging from high to low reliance on stored nutrients. Animals relying mostly on stored reserves are termed ‘capital breeders’, whereas ‘income breeders’ rely mostly on concurrent intake when financing the costs of reproduction. The role and adaptive value of individual variation in these strategies remain elusive. Life-history theory posits that capital breeding should be favoured when offspring reproductive value peaks, typically occurring early in the season, and that current income should increasingly be used with progressing season. Because resource limitation may hamper flexible resource allocation, a corollary prediction is that only good-condition individuals may show the expected seasonal shift in resource use. To test this prediction, we examined stable isotopes (δ13C and δ15N) in blood and lipid-free egg yolk of breeding eider females (Somateria mollissima) from the Baltic Sea to assess the role of individual variation in the use of proteins from local diet vs. stored reserves. Results We show for the first time that individuals from a single population differ in their utilization of stored reserves and concurrent intake to finance the costs of reproduction. Consistent with our prediction, heavy females predominantly used stored reserves for producing egg yolks early in the season, increasingly relying on local feeding with later onset of breeding, whereas light females showed no seasonal change in allocation strategy. Conclusions Stable isotope profiling at the individual level is a powerful tool for monitoring relative changes in investment strategies through time, showing promise as an early warning indicator of ecological change in food webs.
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Affiliation(s)
- Kim Jaatinen
- Novia University of Applied Sciences, Coastal Zone Research Team, Raseborgsvägen 9, FI-10600 Ekenäs, Finland
| | - Markus Öst
- Novia University of Applied Sciences, Coastal Zone Research Team, Raseborgsvägen 9, FI-10600 Ekenäs, Finland ; Environmental and Marine Biology, Faculty of Science and Engineering, Åbo Akademi University, Artillerigatan 6, FI-20520 Turku, Finland
| | - Keith A Hobson
- Environment Canada, 11 Innovation Blvd., Saskatoon, S7N 3H5 Canada ; Department of Biology, University of Western Ontario, 1151 Richmond St., London, ON N6A 5B7 Canada
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Neggazi SA, Noreikiene K, Öst M, Jaatinen K. Reproductive investment is connected to innate immunity in a long-lived animal. Oecologia 2016; 182:347-56. [PMID: 27215635 DOI: 10.1007/s00442-016-3657-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 05/11/2016] [Indexed: 02/07/2023]
Abstract
Life-history theory predicts that organisms optimize their resource allocation strategy to maximize lifetime reproductive success. Individuals can flexibly reallocate resources depending on their life-history stage, and environmental and physiological factors, which lead to variable life-history strategies even within species. Physiological trade-offs between immunity and reproduction are particularly relevant for long-lived species that need to balance current reproduction against future survival and reproduction, but their underlying mechanisms are poorly understood. A major unresolved issue is whether the first-line innate immune function is suppressed by reproductive investment. In this paper, we tested if reproductive investment is associated with the suppression of innate immunity, and how this potential trade-off is resolved depending on physiological state and residual reproductive value. We used long-lived capital-breeding female eiders (Somateria mollissima) as a model. We showed that the innate immune response, measured by plasma bacteria-killing capacity (BKC), was negatively associated with increasing reproductive investment, i.e., with increasing clutch size and advancing incubation stage. Females in a better physiological state, as indexed by low heterophil-to-lymphocyte (H/L) ratios, showed higher BKC during early incubation, but this capacity decreased as incubation progressed, whereas females in poorer state showed low BKC capacity throughout incubation. Although plasma BKC generally declined with increasing H/L ratios, this decrease was most pronounced in young females. Our results demonstrate that reproductive investment can suppress constitutive first-line immune defence in a long-lived bird, but the degree of immunosuppression depends on physiological state and age.
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Affiliation(s)
- Sara A Neggazi
- Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki, Viikinkaari 1, 00014, Helsinki, Finland
| | - Kristina Noreikiene
- Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki, Viikinkaari 1, 00014, Helsinki, Finland.
| | - Markus Öst
- Environmental and Marine Biology, Faculty of Science and Engineering, Åbo Akademi University, Artillerigatan 6, 20520, Turku, Finland.,Coastal Zone Research Team, Novia University of Applied Sciences, Raseborgsvägen 9, 10600, Ekenäs, Finland
| | - Kim Jaatinen
- Coastal Zone Research Team, Novia University of Applied Sciences, Raseborgsvägen 9, 10600, Ekenäs, Finland
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Small-scale spatial and temporal variation in the demographic processes underlying the large-scale decline of eiders in the Baltic Sea. POPUL ECOL 2015. [DOI: 10.1007/s10144-015-0517-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Fox AD, Jónsson JE, Aarvak T, Bregnballe T, Christensen TK, Clausen KK, Clausen P, Dalby L, Holm TE, Pavón-Jordan D, Laursen K, Lehikoinen A, Lorentsen SH, Møller AP, Nordström M, Öst M, Söderquist P, Roland Therkildsen O. Current and Potential Threats to Nordic Duck Populations — A Horizon Scanning Exercise. ANN ZOOL FENN 2015. [DOI: 10.5735/086.052.0404] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Öst M, Jaatinen K. Smart and safe? Antipredator behavior and breeding success are related to head size in a wild bird. Behav Ecol 2015. [DOI: 10.1093/beheco/arv093] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Personality, body condition and breeding experience drive sociality in a facultatively social bird. Anim Behav 2015. [DOI: 10.1016/j.anbehav.2014.12.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Jaatinen K, Seltmann MW, Öst M. Context-dependent stress responses and their connections to fitness in a landscape of fear. J Zool (1987) 2014. [DOI: 10.1111/jzo.12169] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- K. Jaatinen
- Aronia Coastal Zone Research Team; Åbo Akademi University and Novia University of Applied Sciences; Ekenäs Finland
| | - M. W. Seltmann
- Aronia Coastal Zone Research Team; Åbo Akademi University and Novia University of Applied Sciences; Ekenäs Finland
| | - M. Öst
- Aronia Coastal Zone Research Team; Åbo Akademi University and Novia University of Applied Sciences; Ekenäs Finland
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Managing hunted populations through sex-specific season lengths: a case of the Common Eider in the Baltic-Wadden Sea flyway population. EUR J WILDLIFE RES 2014. [DOI: 10.1007/s10344-014-0840-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Stojanovic D, Webb MH, Alderman R, Porfirio LL, Heinsohn R. Discovery of a novel predator reveals extreme but highly variable mortality for an endangered migratory bird. DIVERS DISTRIB 2014. [DOI: 10.1111/ddi.12214] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Dejan Stojanovic
- Fenner School of Environment and Society Australian National University Canberra ACT 0200 Australia
| | - Matthew H. Webb
- Fenner School of Environment and Society Australian National University Canberra ACT 0200 Australia
- Threatened Species and Marine Section Department of Primary Industries, Parks, Water and EnvironmentHobart Tas. 7001 Australia
| | - Rachael Alderman
- Threatened Species and Marine Section Department of Primary Industries, Parks, Water and EnvironmentHobart Tas. 7001 Australia
| | - Luciana L. Porfirio
- Fenner School of Environment and Society Australian National University Landscapes and Policy Hub (NERP) Canberra ACT 0200Australia
| | - Robert Heinsohn
- Fenner School of Environment and Society Australian National University Canberra ACT 0200 Australia
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Guillemain M, Pöysä H, Fox AD, Arzel C, Dessborn L, Ekroos J, Gunnarsson G, Holm TE, Christensen TK, Lehikoinen A, Mitchell C, Rintala J, Møller AP. Effects of climate change on European ducks: what do we know and what do we need to know? WILDLIFE BIOLOGY 2013. [DOI: 10.2981/12-118] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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40
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Seltmann MW, Jaatinen K, Steele BB, Öst M. Boldness and Stress Responsiveness as Drivers of Nest-Site Selection in a Ground-Nesting Bird. Ethology 2013. [DOI: 10.1111/eth.12181] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martin W. Seltmann
- ARONIA Coastal Zone Research Team; Åbo Akademi University & Novia University of Applied Sciences; Ekenäs Finland
| | - Kim Jaatinen
- Evolution, Ecology & Genetics; Research School of Biology; ANU College of Medicine, Biology & Environment; The Australian National University; Canberra Australia
| | | | - Markus Öst
- ARONIA Coastal Zone Research Team; Åbo Akademi University & Novia University of Applied Sciences; Ekenäs Finland
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Jaatinen K, Seltmann MW, Hollmén T, Atkinson S, Mashburn K, Öst M. Context dependency of baseline glucocorticoids as indicators of individual quality in a capital breeder. Gen Comp Endocrinol 2013; 191:231-8. [PMID: 23851039 DOI: 10.1016/j.ygcen.2013.06.022] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 06/17/2013] [Accepted: 06/23/2013] [Indexed: 11/23/2022]
Abstract
Identifying markers of individual quality is a central goal of life-history theory and conservation biology. The 'corticosterone (CORT)-fitness hypothesis' postulates that low fitness signals impaired ability to cope with the environment, resulting in elevated baseline CORT levels. CORT can, however, be negatively, positively or neutrally related to fitness, depending on the context. In order to clarify this controversial issue, we elucidate the utility of using baseline CORT as a correlate of individual fitness in incubating female eiders across variable environments. An increase in serum CORT with decreasing body condition was evident in older, more experienced breeders, while increased clutch mass was associated with elevated serum CORT in females breeding late in the season. For faecal CORT, the expected negative association with body condition was observed only in early breeders. We found a strong increase in faecal CORT with increasing baseline body temperature, indicating the utility of body temperature as a complementary stress indicator. Females in good body condition had a lower baseline body temperature, but this effect was only observed on open islands, a harsher breeding habitat less buffered against weather variability. Females with higher reproductive investment also maintained a lower baseline body temperature. Nest success strongly decreased with increasing serum and faecal CORT concentrations, and individual stress hormone and body temperature profiles were repeatable over years. Although our data support the tenet that baseline CORT is negatively related to fitness, the complex context-dependent effects call for cautious interpretation of relationships between stress physiology and phenotypic quality.
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Affiliation(s)
- Kim Jaatinen
- Evolution, Ecology & Genetics, Research School of Biology, ANU College of Medicine, Biology & Environment, The Australian National University, Canberra ACT 0200, Australia.
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Robertson BA, Rehage JS, Sih A. Ecological novelty and the emergence of evolutionary traps. Trends Ecol Evol 2013; 28:552-60. [PMID: 23756104 DOI: 10.1016/j.tree.2013.04.004] [Citation(s) in RCA: 244] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 04/11/2013] [Accepted: 04/25/2013] [Indexed: 11/25/2022]
Abstract
Human-induced rapid environmental change (HIREC; e.g., climate change or exotic species) has caused global species declines. Although behavioral plasticity has buffered some species against HIREC, maladaptive behavioral scenarios called 'evolutionary traps' are increasingly common, threatening the persistence of affected species. Here, we review examples of evolutionary traps to identify their anthropogenic causes, behavioral mechanisms, and evolutionary bases, and to better forecast forms of HIREC liable to trigger traps. We summarize a conceptual framework for explaining the susceptibility of animals to traps that integrates the cost-benefit approach of standard behavioral ecology with an evolutionary approach (reaction norms) to understanding cue-response systems (signal detection). Finally, we suggest that a significant revision of conceptual thinking in wildlife conservation and management is needed to effectively eliminate and mitigate evolutionary traps.
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Affiliation(s)
- Bruce A Robertson
- Division of Science, Mathematics, and Computing, Bard College, Annandale-on-Hudson, NY 12504, USA.
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Öst M, Jaatinen K. Relative importance of social status and physiological need in determining leadership in a social forager. PLoS One 2013; 8:e64778. [PMID: 23691258 PMCID: PMC3655176 DOI: 10.1371/journal.pone.0064778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 04/18/2013] [Indexed: 11/19/2022] Open
Abstract
Group decisions on the timing of mutually exclusive activities pose a dilemma: monopolized decision-making by a single leader compromises the optimal timing of activities by the others, while independent decision-making by all group members undermines group coherence. Theory suggests that initiation of foraging should be determined by physiological demand in social foragers, thereby resolving the dilemma of group coordination. However, empirical support is scant, perhaps because intrinsic qualities predisposing individuals to leadership (social status, experience or personality), or their interactions with satiation level, have seldom been simultaneously considered. Here, we examine which females initiated foraging in eider (Somateria mollissima) brood-rearing coalitions, characterized by female dominance hierarchies and potentially large individual differences in energy requirements due to strenuous breeding effort. Several physiological and social factors, except for female breeding experience and boldness towards predators, explained foraging initiation. Initiators spent a larger proportion of time submerged during foraging bouts, had poorer body condition and smaller structural size, but they were also aggressive and occupied central positions. Initiation probability also declined with female group size as expected given random assignment of initiators. However, the relative importance of physiological predictors of leadership propensity (active foraging time, body condition, structural size) exceeded those of social predictors (aggressiveness, spatial position) by an order of magnitude. These results confirm recent theoretical work suggesting that 'leading according to need' is an evolutionary viable strategy regardless of group heterogeneity or underlying dominance structure.
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Affiliation(s)
- Markus Öst
- Aronia Coastal Zone Research Team, Åbo Akademi University and Novia University of Applied Sciences, Ekenäs, Finland.
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Stress responsiveness, age and body condition interactively affect flight initiation distance in breeding female eiders. Anim Behav 2012. [DOI: 10.1016/j.anbehav.2012.07.012] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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