1
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Webber QMR, Laforge MP, Bonar M, Vander Wal E. The adaptive value of density-dependent habitat specialization and social network centrality. Nat Commun 2024; 15:4423. [PMID: 38789438 PMCID: PMC11126670 DOI: 10.1038/s41467-024-48657-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Density dependence is a fundamental ecological process. In particular, animal habitat selection and social behavior often affect fitness in a density-dependent manner. The Ideal Free Distribution (IFD) and niche variation hypothesis (NVH) present distinct predictions associated with Optimal Foraging Theory about how the effect of habitat selection on fitness varies with population density. Using caribou (Rangifer tarandus) in Canada as a model system, we test competing hypotheses about how habitat specialization, social behavior, and annual reproductive success (co)vary across a population density gradient. Within a behavioral reaction norm framework, we estimate repeatability, behavioral plasticity, and covariance among social behavior and habitat selection to investigate the adaptive value of sociality and habitat selection. In support of NVH, but not the IFD, we find that at high density habitat specialists had higher annual reproductive success than generalists, but were also less social than generalists, suggesting the possibility that specialists were less social to avoid competition. Our study supports niche variation as a mechanism for density-dependent habitat specialization.
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Affiliation(s)
- Quinn M R Webber
- Cognitive and Behavioural Ecology Interdisciplinary Program, Memorial University of Newfoundland, St. John's, NF, Canada.
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada.
| | - Michel P Laforge
- Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - Maegwin Bonar
- Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Eric Vander Wal
- Cognitive and Behavioural Ecology Interdisciplinary Program, Memorial University of Newfoundland, St. John's, NF, Canada
- Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada
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2
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McLatchie MJ, Emmerson L, Wotherspoon S, Southwell C. Delay in Adélie penguin nest occupation restricts parental investment in nest construction and reduces reproductive output. Ecol Evol 2024; 14:e10988. [PMID: 38476703 PMCID: PMC10928351 DOI: 10.1002/ece3.10988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 01/12/2024] [Accepted: 01/25/2024] [Indexed: 03/14/2024] Open
Abstract
Reproductive success is an important demographic parameter that can be driven by environmental and behavioural factors operating on various spatio-temporal scales. As seabirds breed on land and forage in the ocean, processes occurring in both environments can influence their reproductive success. At various locations around East Antarctica, Adélie penguins' (Pygoscelis adeliae) reproductive success has been negatively linked to extensive sea-ice. In contrast, our study site in the Windmill Islands has limited fast ice present during the breeding season, allowing us to examine drivers of reproductive success under vastly different marine environmental conditions. Here, we examined the reproductive success of 450 Adélie penguin nests over a 10-year period using images obtained from remotely operated cameras. We analysed nest survival in relation to marine and climatic factors, environmental conditions at the camera site and immediately around the nest, and behavioural attributes reflecting parental investment and phenological timing. Our key result was a strong positive association between nest structure and chick survival, particularly when ground moisture and snow cover around the nest were high. Earlier nesting birds were more likely to build bigger nests, although it is unclear whether this is due to more time available to build nests or whether early arrival and high-quality nests are complementary traits. This intrinsic activity is likely to become more important if future predictions of increased snowfall in this region manifest.
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Affiliation(s)
- Madi J. McLatchie
- Department of Climate Change, Energy, the Environment and WaterAustralian Antarctic DivisionKingstonTasmaniaAustralia
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Louise Emmerson
- Department of Climate Change, Energy, the Environment and WaterAustralian Antarctic DivisionKingstonTasmaniaAustralia
| | - Simon Wotherspoon
- Department of Climate Change, Energy, the Environment and WaterAustralian Antarctic DivisionKingstonTasmaniaAustralia
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Colin Southwell
- Department of Climate Change, Energy, the Environment and WaterAustralian Antarctic DivisionKingstonTasmaniaAustralia
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3
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Webber QMR, Albery GF, Farine DR, Pinter-Wollman N, Sharma N, Spiegel O, Vander Wal E, Manlove K. Behavioural ecology at the spatial-social interface. Biol Rev Camb Philos Soc 2023; 98:868-886. [PMID: 36691262 DOI: 10.1111/brv.12934] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/25/2023]
Abstract
Spatial and social behaviour are fundamental aspects of an animal's biology, and their social and spatial environments are indelibly linked through mutual causes and shared consequences. We define the 'spatial-social interface' as intersection of social and spatial aspects of individuals' phenotypes and environments. Behavioural variation at the spatial-social interface has implications for ecological and evolutionary processes including pathogen transmission, population dynamics, and the evolution of social systems. We link spatial and social processes through a foundation of shared theory, vocabulary, and methods. We provide examples and future directions for the integration of spatial and social behaviour and environments. We introduce key concepts and approaches that either implicitly or explicitly integrate social and spatial processes, for example, graph theory, density-dependent habitat selection, and niche specialization. Finally, we discuss how movement ecology helps link the spatial-social interface. Our review integrates social and spatial behavioural ecology and identifies testable hypotheses at the spatial-social interface.
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Affiliation(s)
- Quinn M R Webber
- Department of Integrative Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada
| | - Gregory F Albery
- Department of Biology, Georgetown University, 37th and O Streets, Washington, DC, 20007, USA.,Wissenschaftskolleg zu Berlin, Wallotstraße 19, 14193, Berlin, Germany.,Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, 12587, Berlin, Germany
| | - Damien R Farine
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.,Department of Collective Behavior, Max Planck Institute of Animal Behavior, Universitatsstraße 10, 78464, Constance, Germany.,Division of Ecology and Evolution, Research School of Biology, Australian National University, 46 Sullivans Creek Road, Canberra, ACT, 2600, Australia
| | - Noa Pinter-Wollman
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Nitika Sharma
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Orr Spiegel
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Eric Vander Wal
- Department of Biology, Memorial University, St. John's, NL, A1C 5S7, Canada
| | - Kezia Manlove
- Department of Wildland Resources and Ecology Center, Utah State University, 5200 Old Main Hill, Logan, UT, 84322, USA
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4
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Włodarczyk R, Bouwhuis S, Bichet C, Podlaszczuk P, Chyb A, Indykiewicz P, Dulisz B, Betleja J, Janiszewski T, Minias P. Contrasting haemoparasite prevalence in larid species with divergent ecological niches and migration patterns. Parasitology 2022; 149:1479-1486. [PMID: 35768413 PMCID: PMC11010501 DOI: 10.1017/s0031182022000920] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/27/2022] [Accepted: 06/22/2022] [Indexed: 11/07/2022]
Abstract
Haemoparasites represent a diverse group of vector-borne parasites that infect a wide range of vertebrate hosts. In birds, haemoparasite infection rates may be associated with various ecological and life history traits, including habitat choice, colony size and migration distance. Here, we molecularly assessed the prevalence of 3 main haemoparasite genera (Plasmodium, Haemoproteus and Leucocytozoon) in 2 bird species with different habitat preferences and migratory behaviour: black-headed gulls (Chroicocephalus ridibundus) and common terns (Sterna hirundo). We found that gulls showed a much higher prevalence and diversity of Plasmodium or Haemoproteus (ca. 60% of individuals infected) than terns (zero prevalence). The prevalence of Leucocytozoon was low in both species (<3%). The differences in haemoparasite prevalences may be primarily driven by varying vector encounter rate resulting from different habitat preferences, as black-headed gulls mainly use vector-rich vegetated freshwater habitats, whereas common terns often use vector-poor coastal and brackish habitats. Since common terns migrate further than black-headed gulls, our results did not provide support for an association between haemoparasite prevalence and migratory distance. In gulls, we found a negative association between colony size and infection rates, suggestive of an ideal despotic distribution, and phylogenetic analyses of detected haemoparasite lineages provided evidence for higher host specificity in Haemoproteus than Plasmodium. Our results suggest that the preference for coastal areas and less vegetated habitats in terns may reduce haemoparasite infection rates compared to other larids, regardless of their migratory distance, emphasizing the role of ecological niches in parasite exposure.
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Affiliation(s)
- Radosław Włodarczyk
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237 Łódź, Poland
| | | | - Coraline Bichet
- Centre d'Etudes Biologiques de Chizé, UMR 7372, CNRS-La Rochelle Université, Villiers-en-Bois, France
| | - Patrycja Podlaszczuk
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237 Łódź, Poland
| | - Amelia Chyb
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237 Łódź, Poland
| | - Piotr Indykiewicz
- Department of Biology and Animal Environment, Faculty of Animal Breeding and Biology, Bydgoszcz University of Science and Technology, Mazowiecka 28, 85-084 Bydgoszcz, Poland
| | - Beata Dulisz
- Department of Ecology and Environmental Protection, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Plac Łódzki 3, 10-727 Olsztyn, Poland
| | - Jacek Betleja
- Department of Natural History, Upper Silesian Museum, Plac Jana III Sobieskiego 2, 41-902 Bytom, Poland
| | - Tomasz Janiszewski
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237 Łódź, Poland
| | - Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Banacha 1/3, 90-237 Łódź, Poland
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5
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Schmidt AE, Ballard G, Lescroël A, Dugger KM, Jongsomjit D, Elrod ML, Ainley DG. The influence of subcolony-scale nesting habitat on the reproductive success of Adélie penguins. Sci Rep 2021; 11:15380. [PMID: 34321573 PMCID: PMC8319293 DOI: 10.1038/s41598-021-94861-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 05/13/2021] [Indexed: 11/14/2022] Open
Abstract
Group-size variation is common in colonially breeding species, including seabirds, whose breeding colonies can vary in size by several orders of magnitude. Seabirds are some of the most threatened marine taxa and understanding the drivers of colony size variation is more important than ever. Reproductive success is an important demographic parameter that can impact colony size, and it varies in association with a number of factors, including nesting habitat quality. Within colonies, seabirds often aggregate into distinct groups or subcolonies that may vary in quality. We used data from two colonies of Adélie penguins 73 km apart on Ross Island, Antarctica, one large and one small to investigate (1) How subcolony habitat characteristics influence reproductive success and (2) How these relationships differ at a small (Cape Royds) and large (Cape Crozier) colony with different terrain characteristics. Subcolonies were characterized using terrain attributes (elevation, slope aspect, slope steepness, wind shelter, flow accumulation), as well group characteristics (area/size, perimeter-to-area ratio, and proximity to nest predators). Reproductive success was higher and less variable at the larger colony while subcolony characteristics explained more of the variance in reproductive success at the small colony. The most important variable influencing subcolony quality at both colonies was perimeter-to-area ratio, likely reflecting the importance of nest predation by south polar skuas along subcolony edges. The small colony contained a higher proportion of edge nests thus higher potential impact from skua nest predation. Stochastic environmental events may facilitate smaller colonies becoming “trapped” by nest predation: a rapid decline in the number of breeding individuals may increase the proportion of edge nests, leading to higher relative nest predation and hindering population recovery. Several terrain covariates were retained in the final models but which variables, the shapes of the relationships, and importance varied between colonies.
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Affiliation(s)
| | - Grant Ballard
- Point Blue Conservation Science, Petaluma, CA, 94954, USA
| | | | - Katie M Dugger
- U.S. Geological Survey, Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, 97331, USA
| | | | - Megan L Elrod
- Point Blue Conservation Science, Petaluma, CA, 94954, USA
| | - David G Ainley
- H.T. Harvey & Associates Ecological Consultants, Los Gatos, CA, 95032, USA
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6
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Niederhauser JM, Slevin MC, Noonburg EG, Anderson RC. Body size, habitat quality, and territory defense in Bachman’s sparrow. BEHAVIOUR 2021. [DOI: 10.1163/1568539x-bja10079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Many wild populations of animals conform to the ideal despotic distribution (IDD) in which more competitive individuals exclude less competitive individuals from high quality resources. Body size and aggressiveness are two important traits for resource defense, and they positively covary so that larger individuals are usually more aggressive. Using Bachman’s sparrows, we tested the hypothesis that larger birds are more aggressive and are thus able to compete for the best quality territories. We found that larger males were more aggressive, and more aggressive birds fledged at least one young. However, we did not find consistent relationships between aggressiveness and habitat characteristics. Our results suggest that Bachman’s sparrows meet most of the predictions of the IDD. Frequent ecological disturbances, such as fires, might disrupt the IDD or make it difficult to detect. Additional studies are needed to test for relationships between ecological disturbances and territorial behaviour.
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Affiliation(s)
| | - Morgan C. Slevin
- Department of Biological Sciences, Florida Atlantic University, Davie, FL 33314, USA
| | - Erik G. Noonburg
- Department of Biological Sciences, Florida Atlantic University, Davie, FL 33314, USA
| | - Rindy C. Anderson
- Department of Biological Sciences, Florida Atlantic University, Davie, FL 33314, USA
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7
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Minias P, Gach K, Włodarczyk R, Bartos M, Drzewińska-Chańko J, Rembowski M, Jakubas D, Janiszewski T. Colony size as a predictor of breeding behaviour in a common waterbird. PLoS One 2020; 15:e0241602. [PMID: 33137151 PMCID: PMC7605668 DOI: 10.1371/journal.pone.0241602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 10/17/2020] [Indexed: 11/21/2022] Open
Abstract
The choice of colony size may have profound consequences for individual fitness in colonially breeding birds, but at the same time it may require certain behavioural adaptations. Here, we aimed to examine behavioural divergence of common terns Sterna hirundo nesting in colonies of different size. For this purpose, we promoted establishment of small (<35 pairs) and large (>100 pairs) tern colonies under uniform ecological and environmental conditions by providing attractive patches of nesting substrate (floating rafts) at a single site. We combined video recording and GPS-tracking to assess communal and individual defence initiation rate, intra-specific aggression rate, and foraging flight characteristics. We found that birds from larger colonies more frequently engaged in communal defence and they performed longer foraging flights, while terns from smaller colonies more frequently showed individual defence behaviours. Also, intra-specific aggression rate was higher in smaller colonies, but this effect was primarily attributed to a higher proportion of edge breeding pairs, which were more aggressive. Our results suggest that various colony sizes may be associated with different behavioural syndromes, which comprise of diverse personality traits, such as social responsiveness, social tolerance, or propensity for aggression. It remains to be tested whether these behavioural differences reflect processes of phenotypic sorting among colonies of different size or whether they are a result of behavioural plasticity under different social contexts.
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Affiliation(s)
- Piotr Minias
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
- * E-mail:
| | - Kamila Gach
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
| | - Radosław Włodarczyk
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
| | - Maciej Bartos
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
| | - Joanna Drzewińska-Chańko
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
| | - Miłosz Rembowski
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
| | - Dariusz Jakubas
- Department of Vertebrate Ecology and Zoology, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Tomasz Janiszewski
- Department of Biodiversity Studies and Bioeducation, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
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8
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O'Neil ST, Vucetich JA, Beyer DE, Hoy SR, Bump JK. Territoriality drives preemptive habitat selection in recovering wolves: Implications for carnivore conservation. J Anim Ecol 2020; 89:1433-1447. [PMID: 32145068 DOI: 10.1111/1365-2656.13199] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 02/05/2020] [Indexed: 11/29/2022]
Abstract
According to the ideal-free distribution (IFD), individuals within a population are free to select habitats that maximize their chances of success. Assuming knowledge of habitat quality, the IFD predicts that average fitness will be approximately equal among individuals and between habitats, while density varies, implying that habitat selection will be density dependent. Populations are often assumed to follow an IFD, although this assumption is rarely tested with empirical data, and may be incorrect when territoriality indicates habitat selection tactics that deviate from the IFD (e.g. ideal-despotic distribution or ideal-preemptive distribution). When territoriality influences habitat selection, species' density will not directly reflect components of fitness such as reproductive success or survival. In such cases, assuming an IFD can lead to false conclusions about habitat quality. We tested theoretical models of density-dependent habitat selection on a species known to exhibit territorial behaviour in order to determine whether commonly applied habitat models are appropriate under these circumstances. We combined long-term radiotelemetry and census data from grey wolves Canis lupus in the Upper Peninsula of Michigan, USA to relate spatiotemporal variability in wolf density to underlying classifications of habitat within a hierarchical state-space modelling framework. We then iteratively applied isodar analysis to evaluate which distribution of habitat selection best described this recolonizing wolf population. The wolf population in our study expanded by >1,000% during our study (~50 to >600 individuals), and density-dependent habitat selection was most consistent with the ideal-preemptive distribution, as opposed to the ideal-free or ideal-despotic alternatives. Population density of terrestrial carnivores may not be positively correlated with the fitness value of their habitats, and density-dependent habitat selection patterns may help to explain complex predator-prey dynamics and cascading indirect effects. Source-sink population dynamics appear likely when species exhibit rapid growth and occupy interspersed habitats of contrasting quality. These conditions are likely and have implications for large carnivores in many systems, such as areas in North America and Europe where large predator species are currently recolonizing their former ranges.
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Affiliation(s)
- Shawn T O'Neil
- School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Dr., Houghton, MI, USA
| | - John A Vucetich
- School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Dr., Houghton, MI, USA
| | - Dean E Beyer
- School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Dr., Houghton, MI, USA.,Wildlife Division, Michigan Department of Natural Resources, 1990 U.S. Hwy 41 So, Marquette, MI, USA
| | - Sarah R Hoy
- School of Forest Resources and Environmental Science, Michigan Technological University, 1400 Townsend Dr., Houghton, MI, USA
| | - Joseph K Bump
- Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, 2003 Upper Buford Circle, St. Paul, MN, USA
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9
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Zapata P, Ballesteros-Cano R, Colomer P, Bertolero A, Viana P, Lacorte S, Santos FJ. Presence and impact of Stockholm Convention POPs in gull eggs from Spanish and Portuguese natural and national parks. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 633:704-715. [PMID: 29597164 DOI: 10.1016/j.scitotenv.2018.03.081] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 03/07/2018] [Accepted: 03/08/2018] [Indexed: 06/08/2023]
Abstract
The aim of the present work was to comparatively assess the occurrence and impact of persistent organic pollutants (POPs) in nine natural and national parks from Spain and Portugal using gull eggs (Larus michahellis and L. audouinii) as bioindicators of environmental contamination. Sampling was performed during the breeding season of 2016. Compounds studied include polychlorinated biphenyls (PCBs), organochlorinated pesticides (OC pesticides), perfluorooctane sulfonic acid (PFOS) and polybrominated diphenyl ethers (PBDEs), and were analyzed using mass spectrometric based techniques. The results showed a high contamination by PCBs in all colonies, with total levels ranging from 59 to 1278ng/g wet weight (ww), despite their use is not currently authorized. OC pesticides were also present in all colonies, with a high incidence of 4,4'-DDE in gull eggs at levels up to 218±50ng/g ww in L. michahellis and 760±412ng/g ww in L. audouinii from the Ebro Delta natural park. PBDEs and PFOS were also detected at levels up to 91.7±21.3ng/g ww, which can be attributed to a more recent use. Except for PBDEs, the POP levels in eggs from L. audouinii were higher than in L. michahellis, presumably associated to the fish-based diet of the former. Finally, the effect of POP levels on eggshell parameters (volume, eggshell thickness and desiccation index) were investigated for each colony and gull species in order to evaluate the egg viability and, therefore, the reproduction success.
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Affiliation(s)
- Pablo Zapata
- Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Catalonia, Spain
| | - Rubèn Ballesteros-Cano
- Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Catalonia, Spain
| | - Pere Colomer
- Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Catalonia, Spain
| | - Albert Bertolero
- Associació Ornitològica Picampall de les Terres de l'Ebre, Amposta, Spain
| | - Paula Viana
- Divisao de Qualidade da Água, Instituto da Água I.P., Av. Almirante Gago Coutinho, 30, 1049-066 Lisboa, Portugal
| | - Silvia Lacorte
- Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Catalonia, Spain.
| | - Francisco Javier Santos
- Department of Analytical Chemistry, University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain
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10
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Martínez‐Abraín A, Jiménez J, Oro D. Pax Romana: ‘refuge abandonment’ and spread of fearless behavior in a reconciling world. Anim Conserv 2018. [DOI: 10.1111/acv.12429] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - J. Jiménez
- Servicio de Vida Silvestre Generalitat Valenciana Valencia Spain
| | - D. Oro
- Instituto Mediterráneo de Estudios Avanzados (CSIC‐UIB) Esporles Spain
- Centro de Estudios Avanzados de Blanes (CSIC) Girona Spain
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11
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Kawaguchi T, Desrochers A. A time-lagged effect of conspecific density on habitat selection by snowshoe hare. PLoS One 2018; 13:e0190643. [PMID: 29320564 PMCID: PMC5761860 DOI: 10.1371/journal.pone.0190643] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 12/18/2017] [Indexed: 11/29/2022] Open
Abstract
Ideal free distribution theory predicts that increased conspecific density redistributes individuals to low-density, suboptimal habitat. However, possible lags in response to population density remain poorly documented. Snowshoe hares (Lepus americanus) may exhibit density-dependent habitat selection due to its marked variation in population density. Based on 11 years (2004–2014) of snow tracking in Quebec (Canada), we investigated snowshoe hares’ short-term and delayed habitat selection responses to population density. We predicted that at high densities, hare distribution expands into low-density habitat, thus weakening the association between hares and high-density habitat. We surveyed hare tracks along 95 km of transects on average each year and georeferenced 14,240 tracks. We used Generalized Estimating Equations for track count per 100 m transect segment as a function of the proportion of different forest age classes (0–20 y, 20–40 y and 40–80 y) within 50 m of the segments. We used model coefficients for each age class as a measure of habitat preference, and modeled those coefficients as a function of a population density index in current and previous winters. Coefficients for 20- to 40-y-old forests were positive each year, indicating that this habitat was preferred. The association between track counts and 20- to 40-y-old forest significantly declined with density during the previous winter, suggesting that hare spread from preferred forest with a lagged response to density. To our knowledge, no previous empirical studies have documented a lagged habitat selection response to population density. Time lags offer possible explanation for documented deviations from ideal free distribution models.
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Affiliation(s)
- Toshinori Kawaguchi
- Centre d’étude de la forêt, and Département des sciences du bois et de la forêt, Université Laval, Québec, Québec, Canada
- * E-mail:
| | - André Desrochers
- Centre d’étude de la forêt, and Département des sciences du bois et de la forêt, Université Laval, Québec, Québec, Canada
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12
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Fay R, Barbraud C, Delord K, Weimerskirch H. From early life to senescence: individual heterogeneity in a long-lived seabird. ECOL MONOGR 2017; 88:60-73. [PMID: 30122788 PMCID: PMC6084314 DOI: 10.1002/ecm.1275] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 06/01/2017] [Accepted: 06/13/2017] [Indexed: 01/20/2023]
Abstract
Although population studies have long assumed that all individuals of a given sex and age are identical, ignoring among‐individual differences may strongly bias our perception of eco‐evolutionary processes. Individual heterogeneity, often referred to as individual quality, has received increasing research attention in the last decades. However, there are still substantial gaps in our current knowledge. For example, there is little information on how individual heterogeneity influences various life‐history traits simultaneously, and studies describing individual heterogeneity in wild populations are generally not able to jointly identify possible sources of this variation. Here, based on a mark–recapture data set of 9,685 known‐aged Wandering Albatrosses (Diomedea exulans), we investigated the existence of individual quality over the entire life cycle of this species, from early life to senescence. Using finite mixture models, we investigated the expression of individual heterogeneity in various demographic traits, and examined the origin of these among‐individual differences by considering the natal environmental conditions. We found that some individuals consistently outperformed others during most of their life. In old age, however, the senescence rate was stronger in males that showed high demographic performance at younger ages. Variation in individual quality seemed strongly affected by extrinsic factors experienced during the ontogenetic period. We found that individuals born in years with high population density tended to have lower performances during their lifespan, suggesting delayed density dependence effects through individual quality. Our study showed that among‐individual differences could be important in structuring individual life history trajectories, with substantial consequences at higher ecological levels such as population dynamics.
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Affiliation(s)
- Rémi Fay
- Centre d'Etudes Biologiques de Chizé UMR 7372 CNRS/Univ La Rochelle 79360 Villiers-en-Bois France
| | - Christophe Barbraud
- Centre d'Etudes Biologiques de Chizé UMR 7372 CNRS/Univ La Rochelle 79360 Villiers-en-Bois France
| | - Karine Delord
- Centre d'Etudes Biologiques de Chizé UMR 7372 CNRS/Univ La Rochelle 79360 Villiers-en-Bois France
| | - Henri Weimerskirch
- Centre d'Etudes Biologiques de Chizé UMR 7372 CNRS/Univ La Rochelle 79360 Villiers-en-Bois France
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Strickland BA, Vilella FJ, Belant JL. Scale-Dependent Habitat Selection and Size-Based Dominance in Adult Male American Alligators. PLoS One 2016; 11:e0161814. [PMID: 27588947 PMCID: PMC5010255 DOI: 10.1371/journal.pone.0161814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 08/12/2016] [Indexed: 11/18/2022] Open
Abstract
Habitat selection is an active behavioral process that may vary across spatial and temporal scales. Animals choose an area of primary utilization (i.e., home range) then make decisions focused on resource needs within patches. Dominance may affect the spatial distribution of conspecifics and concomitant habitat selection. Size-dependent social dominance hierarchies have been documented in captive alligators, but evidence is lacking from wild populations. We studied habitat selection for adult male American alligators (Alligator mississippiensis; n = 17) on the Pearl River in central Mississippi, USA, to test whether habitat selection was scale-dependent and individual resource selectivity was a function of conspecific body size. We used K-select analysis to quantify selection at the home range scale and patches within the home range to determine selection congruency and important habitat variables. In addition, we used linear models to determine if body size was related to selection patterns and strengths. Our results indicated habitat selection of adult male alligators was a scale-dependent process. Alligators demonstrated greater overall selection for habitat variables at the patch level and less at the home range level, suggesting resources may not be limited when selecting a home range for animals in our study area. Further, diurnal habitat selection patterns may depend on thermoregulatory needs. There was no relationship between resource selection or home range size and body size, suggesting size-dependent dominance hierarchies may not have influenced alligator resource selection or space use in our sample. Though apparent habitat suitability and low alligator density did not manifest in an observed dominance hierarchy, we hypothesize that a change in either could increase intraspecific interactions, facilitating a dominance hierarchy. Due to the broad and diverse ecological roles of alligators, understanding the factors that influence their social dominance and space use can provide great insight into their functional role in the ecosystem.
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Affiliation(s)
- Bradley A. Strickland
- Department of Wildlife, Fisheries, and Aquaculture, Mississippi State University, Mississippi State, Mississippi, United States of America
- * E-mail:
| | - Francisco J. Vilella
- U.S. Geological Survey, Mississippi Cooperative Fish and Wildlife Research Unit, Mississippi State University, Mississippi State, Mississippi, United States of America
| | - Jerrold L. Belant
- Carnivore Ecology Laboratory, Forest and Wildlife Research Center, Mississippi State University, Mississippi State, Mississippi, United States of America
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Rebstock GA, Boersma PD, García-Borboroglu P. Changes in habitat use and nesting density in a declining seabird colony. POPUL ECOL 2015. [DOI: 10.1007/s10144-015-0523-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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15
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Release of constraints on nest-site selection in burrow-nesting petrels following invasive rat eradication. Biol Invasions 2014. [DOI: 10.1007/s10530-014-0807-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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16
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Circulation of a Meaban-like virus in yellow-legged gulls and seabird ticks in the western Mediterranean basin. PLoS One 2014; 9:e89601. [PMID: 24625959 PMCID: PMC3953012 DOI: 10.1371/journal.pone.0089601] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 01/21/2014] [Indexed: 12/23/2022] Open
Abstract
In recent years, a number of zoonotic flaviviruses have emerged worldwide, and wild birds serve as their major reservoirs. Epidemiological surveys of bird populations at various geographical scales can clarify key aspects of the eco-epidemiology of these viruses. In this study, we aimed at exploring the presence of flaviviruses in the western Mediterranean by sampling breeding populations of the yellow-legged gull (Larus michahellis), a widely distributed, anthropophilic, and abundant seabird species. For 3 years, we sampled eggs from 19 breeding colonies in Spain, France, Algeria, and Tunisia. First, ELISAs were used to determine if the eggs contained antibodies against flaviviruses. Second, neutralization assays were used to identify the specific flaviviruses present. Finally, for colonies in which ELISA-positive eggs had been found, chick serum samples and potential vectors, culicid mosquitoes and soft ticks (Ornithodoros maritimus), were collected and analyzed using serology and PCR, respectively. The prevalence of flavivirus-specific antibodies in eggs was highly spatially heterogeneous. In northeastern Spain, on the Medes Islands and in the nearby village of L'Escala, 56% of eggs had antibodies against the flavivirus envelope protein, but were negative for neutralizing antibodies against three common flaviviruses: West Nile, Usutu, and tick-borne encephalitis viruses. Furthermore, little evidence of past flavivirus exposure was obtained for the other colonies. A subset of the Ornithodoros ticks from Medes screened for flaviviral RNA tested positive for a virus whose NS5 gene was 95% similar to that of Meaban virus, a flavivirus previously isolated from ticks of Larus argentatus in western France. All ELISA-positive samples subsequently tested positive for Meaban virus neutralizing antibodies. This study shows that gulls in the western Mediterranean Basin are exposed to a tick-borne Meaban-like virus, which underscores the need of exploring the spatial and temporal distribution of this flavivirus as well as its potential pathogenicity for animals and humans.
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Evidence for density-dependent habitat occupancy at varying scales in an expanding bird population. POPUL ECOL 2014. [DOI: 10.1007/s10144-014-0435-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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18
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Evolution of within-colony distribution patterns of birds in response to habitat structure. Behav Ecol Sociobiol 2014; 68:851-859. [PMID: 24771961 PMCID: PMC3986900 DOI: 10.1007/s00265-014-1697-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/14/2014] [Accepted: 02/17/2014] [Indexed: 11/14/2022]
Abstract
It has long been suggested that habitat structure affects how colonial birds are distributed within their nesting aggregations, but this hypothesis has never been formally tested. The aim of this study was to test for a correlated evolution between habitat heterogeneity and within-colony distributions of Ciconiiformes by using Pagel’s general method of comparative analysis for discrete variables. The analysis indicated that central-periphery gradients of distribution (high-quality individuals occupying central nesting locations) prevail in species breeding in homogeneous habitats. These were mainly ground-nesting larids and spheniscids, where clear central-periphery patterns were recorded in ca. 80 % of the taxa. Since homogeneous habitats provide little variation in the physical quality of nest sites, central nesting locations should be largely preferred because they give better protection against predators by means of more efficient predator detection and deterrence. By contrast, central-periphery gradients tended to be disrupted in heterogeneous habitats, where 75 % of colonial Ciconiiform species showed uniform patterns of distribution. Under this model of distribution, edge nest sites of high physical quality confer higher fitness benefits in comparison to low-quality central sites, and thus, high-quality pairs are likely to choose nest sites irrespectively of their within-colony location. Breeding in homogeneous habitats and uniform distribution patterns were identified as probable ancestral states in Ciconiiformes, but there was a significant transition rate from uniform to central-periphery distributions in species occupying homogeneous habitats.
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LaMontagne JM, Williams CT, Donald JL, Humphries MM, McAdam AG, Boutin S. Linking intraspecific variation in territory size, cone supply, and survival of North American red squirrels. J Mammal 2013. [DOI: 10.1644/12-mamm-a-245.1] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Gueijman A, Ayali A, Ram Y, Hadany L. Dispersing away from bad genotypes: the evolution of Fitness-Associated Dispersal (FAD) in homogeneous environments. BMC Evol Biol 2013; 13:125. [PMID: 23777293 PMCID: PMC3704926 DOI: 10.1186/1471-2148-13-125] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 05/15/2013] [Indexed: 11/10/2022] Open
Abstract
Background Dispersal is a major factor in ecological and evolutionary dynamics. Although empirical evidence shows that the tendency to disperse varies among individuals in many organisms, the evolution of dispersal patterns is not fully understood. Previous theoretical studies have shown that condition-dependent dispersal may evolve as a means to move to a different environment when environments are heterogeneous in space or in time. However, dispersal is also a means to genetically diversify offspring, a genetic advantage that might be particularly important when the individual fitness is low. We suggest that plasticity in dispersal, in which fit individuals are less likely to disperse (Fitness-Associated Dispersal, or FAD), can evolve due to its evolutionary advantages even when the environment is homogeneous and stable, kin competition is weak, and the cost of dispersal is high. Results Using stochastic simulations we show that throughout the parameter range, selection favors FAD over uniform dispersal (in which all individuals disperse with equal probability). FAD also has significant long-term effects on the mean fitness and genotypic variance of the population. Conclusions We show that FAD evolves under a very wide parameter range, regardless of its effects on the population mean fitness. We predict that individuals of low quality will have an increased tendency for dispersal, even when the environment is homogeneous, there is no direct competition with neighbors, and dispersal carries significant costs.
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Affiliation(s)
- Ariel Gueijman
- Department of Molecular Biology and Ecology of Plants, Tel Aviv University, Tel-Aviv 69978, Israel
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21
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Loehle C. Differential sorting of individuals in territorial species affects apparent habitat quality. J Wildl Manage 2013. [DOI: 10.1002/jwmg.574] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Craig Loehle
- National Council for Air and Stream Improvement, Inc.; 552 S Washington Street, Suite 224 Naperville IL 60540 USA
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Cardador L, Carrete M, Mañosa S. Inter-individual variability and conspecific densities: consequences for population regulation and range expansion. PLoS One 2012; 7:e33375. [PMID: 22479391 PMCID: PMC3314022 DOI: 10.1371/journal.pone.0033375] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 02/14/2012] [Indexed: 12/03/2022] Open
Abstract
The presence of conspecifics can strongly modulate the quality of a breeding site. Both positive and negative effects of conspecifics can act on the same individuals, with the final balance between its costs and benefits depending on individual characteristics. A particular case of inter-individual variation found in many avian species is chromatic variability. Among birds, plumage coloration can co-vary with morphology, physiology and behavior as well as with age. These relationships suggest that cost-benefit balances of conspecific presence may be different for individuals with different colorations. We investigated whether inter-individual variability affects population regulation and expansion processes by analyzing potential differences in density-dependent productivity and settlement patterns in relation to plumage coloration in a population of a long-lived avian species recently undergoing a notable increase in numbers and distribution range. Our results show strong variation in the effect of density on productivity of breeding pairs depending on plumage coloration of their members. Productivity of dark birds decreased along the breeding density gradient while that of lighter breeders remained unchanged with conspecific density. In a similar way, our results showed an uneven occupation of localities by individuals with different plumage coloration in relation to local densities, with the breeding of lighter harriers more aggregated than that of dark-brown ones. At a population scale, darker birds had higher probability of colonization of the most isolated, empty sites. Explanations for species range expansion and population regulation usually make the inferred assumption that species traits are similar among individuals. However, in most species, there could be individual variation in niche requirements or dispersal propensities among individuals with different traits. Our results contribute to the growing appreciation that the individual traits, but not the average trait at the level of species, are important during population regulation and expansion processes.
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Affiliation(s)
- Laura Cardador
- Departament de Biologia Animal, Universitat de Barcelona, Barcelona, Spain.
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Vicente J, Bertolero A, Meyer J, Viana P, Lacorte S. Distribution of perfluorinated compounds in Yellow-legged gull eggs (Larus michahellis) from the Iberian Peninsula. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 416:468-475. [PMID: 22209369 DOI: 10.1016/j.scitotenv.2011.11.085] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 11/29/2011] [Accepted: 11/30/2011] [Indexed: 05/31/2023]
Abstract
This study is aimed to evaluate the presence and distribution of Perfluorinated Compounds (PFCs) in Yellow-legged gull eggs (Larus michahellis) collected from 8 National or Natural Parks from the Iberian Peninsula. In each colony, 12 eggs were randomly collected and pooled from 3 areas of the colony and analyzed using liquid-solid extraction and liquid chromatography coupled to tandem mass spectrometry. Perfluorooctanate sulfonate (PFOS) was the only compound detected in the eggs and its presence was higher in the colonies situated in NE Iberian Peninsula due to the more industrial and mass urbanization in this area compared to the SW Mediterranean or Atlantic colonies. Accordingly, the Medes site, followed by the Ebro Delta and Columbretes, all situated in the NW Mediterranean coast, contained the highest PFOS levels (40.5-54.0ng/g-ww). In all other colonies, PFOS was detected at levels of 10.1-18.6ng/g-ww. Egg shell biometry was studied and it was found that the presence of PFOS did not affect the development of the egg.
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Affiliation(s)
- Joana Vicente
- Department of Environmental Chemistry, Insitute of Environmental Diagnostics and Water Studies, CSIC, Jordi Girona 18-26, 08034 Barcelona, Catalonia, Spain
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Almaraz P, Oro D. Size-mediated non-trophic interactions and stochastic predation drive assembly and dynamics in a seabird community. Ecology 2011; 92:1948-58. [PMID: 22073786 DOI: 10.1890/11-0181.1] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Theoretical and empirical evidence suggests that body size is a major life-history trait impacting on the structure and functioning of complex food webs. However, long-term analyses of size-dependent interactions within simpler network modules, for instance, competitive guilds, are scant. Here, we model the assembly dynamics of the largest breeding seabird community in the Mediterranean basin during the last 30 years. This unique data set allowed us to test, through a "natural experiment," whether body size drove the assembly and dynamics of an ecological guild growing from very low numbers after habitat protection. Although environmental stochasticity accounted for most of community variability, the population variance explained by interspecific interactions, albeit small, decreased sharply with increasing body size. Since we found a demographic gradient along a body size continuum, in which population density and stability increase with increasing body size, the numerical effects of interspecific interactions were proportionally higher on smaller species than on larger ones. Moreover, we found that the per capita interaction coefficients were larger the higher the size ratio among competing species, but only for the set of interactions in which the species exerting the effect was greater. This provides empirical evidence for long-term asymmetric interspecific competition, which ultimately prompted the local extinction of two small species during the study period. During the assembly process stochastic predation by generalist carnivores further triggered community reorganizations and global decays in population synchrony, which disrupted the pattern of interspecific interactions. These results suggest that the major patterns detected in complex food webs can hold as well for simpler sub-modules of these networks involving non-trophic interactions, and highlight the shifting ecological processes impacting on assembling vs. asymptotic communities.
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Affiliation(s)
- Pablo Almaraz
- Department of Applied Biology, Universidad Miguel Hernández, Carretera de Beniel, km. 3.2, 33012 Orihuela, Alicante, Spain.
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26
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Libal NS, Belant JL, Leopold BD, Wang G, Owen PA. Despotism and risk of infanticide influence grizzly bear den-site selection. PLoS One 2011; 6:e24133. [PMID: 21935378 PMCID: PMC3173359 DOI: 10.1371/journal.pone.0024133] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 08/05/2011] [Indexed: 11/30/2022] Open
Abstract
Given documented social dominance and intraspecific predation in bear populations, the ideal despotic distribution model and sex hypothesis of sexual segregation predict adult female grizzly bears (Ursus arctos) will avoid areas occupied by adult males to reduce risk of infanticide. Under ideal despotic distribution, juveniles should similarly avoid adult males to reduce predation risk. Den-site selection and use is an important component of grizzly bear ecology and may be influenced by multiple factors, including risk from conspecifics. To test the role of predation risk and the sex hypothesis of sexual segregation, we compared adult female (n = 142), adult male (n = 36), and juvenile (n = 35) den locations in Denali National Park and Preserve, Alaska, USA. We measured elevation, aspect, slope, and dominant land cover for each den site, and used maximum entropy modeling to determine which variables best predicted den sites. We identified the global model as the best-fitting model for adult female (area under curve (AUC) = 0.926) and elevation as the best predictive variable for adult male (AUC = 0.880) den sites. The model containing land cover and elevation best-predicted juvenile (AUC = 0.841) den sites. Adult females spatially segregated from adult males, with dens characterized by higher elevations (mean= 1,412 m, SE = 52) and steeper slopes (mean = 21.9°, SE = 1.1) than adult male (elevation: mean = 1,209 m, SE = 76; slope: mean = 15.6°, SE = 1.9) den sites. Juveniles used a broad range of landscape attributes but did not avoid adult male denning areas. Observed spatial segregation by adult females supports the sex hypothesis of sexual segregation and we suggest is a mechanism to reduce risk of infanticide. Den site selection of adult males is likely related to distribution of food resources during spring.
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Affiliation(s)
- Nathan S Libal
- Carnivore Ecology Laboratory, Forest and Wildlife Research Center, Mississippi State University, Mississippi State, Mississippi, United States of America.
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27
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Predicting local population distributions around a central shelter based on a predation risk-growth trade-off. Ecol Modell 2011. [DOI: 10.1016/j.ecolmodel.2011.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Nevoux M, Gimenez O, Arlt D, Nicoll M, Jones C, Norris K. Population regulation of territorial species: both site dependence and interference mechanisms matter. Proc Biol Sci 2010; 278:2173-81. [PMID: 21159674 DOI: 10.1098/rspb.2010.2352] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Spatial patterns of site occupancy are commonly driven by habitat heterogeneity and are thought to shape population dynamics through a site-dependent regulatory mechanism. When examining this, however, most studies have only focused on a single vital rate (reproduction), and little is known about how space effectively contributes to the regulation of population dynamics. We investigated the underlying mechanisms driving density-dependent processes in vital rates in a Mauritius kestrel population where almost every individual was monitored. Different mechanisms acted on different vital rates, with breeding success regulated by site dependence (differential use of space) and juvenile survival by interference (density-dependent competition for resources). Although territorial species are frequently assumed to be regulated through site dependence, we show that interference was the key regulatory mechanism in this population. Our integrated approach demonstrates that the presence of spatial processes regarding one trait does not mean that they necessarily play an important role in regulating population growth, and demonstrates the complexity of the regulatory process.
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Affiliation(s)
- Marie Nevoux
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Earley Gate, PO Box 237, Reading RG6 6AR, UK.
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Comparing demographic parameters for philopatric and immigrant individuals in a long-lived bird adapted to unstable habitats. Oecologia 2010; 165:935-45. [PMID: 20842380 DOI: 10.1007/s00442-010-1773-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 08/25/2010] [Indexed: 10/19/2022]
Abstract
Theoretical models about the benefits of philopatry predict that immigrant fitness can be higher, lower or similar to that of philopatrics depending on habitat heterogeneity, dispersal costs, distance between patches or population densities. In this study, we compared transience rates, local survival and recruitment among philopatric and immigrant individuals of Audouin's gull Larus audouinii, a long-lived bird with high dispersal capacities. Several previous studies have shown that these capacities were probably the result of adaptation to unstable and highly discrete habitats; hence, we tested the hypothesis that fitness components for philopatrics and immigrants were similar. During 1988-2006, ca. 27,800 chicks were marked in 31 colonies in the western Mediterranean metapopulation, and more than 52,000 resightings were made in a single, high-quality colony, to estimate local demographic parameters by capture-recapture analyses. Results suggest that, even though parameters related to site-tenacity (e.g. recapture rates) were higher for philopatrics than for immigrants, survival and recruitment were fundamentally similar. Small differences between philopatrics and immigrants were probably influenced by a highly suitable habitat at the study site, which reduced dispersal costs for immigrants; furthermore, the similarities in most fitness components were also probably the result of a life-history strategy of a species living in unpredictable, unstable habitats with high emigration rates among local populations, and with a relatively low cost of dispersal.
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Balkiz O, Béchet A, Rouan L, Choquet R, Germain C, Amat JA, Rendón-Martos M, Baccetti N, Nissardi S, Ozesmi U, Pradel R. Experience-dependent natal philopatry of breeding greater flamingos. J Anim Ecol 2010; 79:1045-56. [PMID: 20626499 DOI: 10.1111/j.1365-2656.2010.01721.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Ozge Balkiz
- CEFE-CNRS, Equipe Biométrie et Biologie des Populations, 1919 Route de Mende, 34293 Montpellier, France
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Bonebrake TC, Beissinger SR. Predation and infanticide influence ideal free choice by a parrot occupying heterogeneous tropical habitats. Oecologia 2010; 163:385-93. [PMID: 20135326 PMCID: PMC2871107 DOI: 10.1007/s00442-010-1566-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Accepted: 01/11/2010] [Indexed: 10/27/2022]
Abstract
The ideal free distribution (IFD) predicts that organisms will disperse to sites that maximize their fitness based on availability of resources. Habitat heterogeneity underlies resource variation and influences spatial variation in demography and the distribution of populations. We relate nest site productivity at multiple scales measured over a decade to habitat quality in a box-nesting population of Forpus passerinus (green-rumped parrotlets) in Venezuela to examine critical IFD assumptions. Variation in reproductive success at the local population and neighborhood scales had a much larger influence on productivity (fledglings per nest box per year) than nest site or female identity. Habitat features were reliable cues of nest site quality. Nest sites with less vegetative cover produced greater numbers of fledglings than sites with more cover. However, there was also a competitive cost to nesting in high-quality, low-vegetative cover nest boxes, as these sites experienced the most infanticide events. In the lowland local population, water depth and cover surrounding nest sites were related with F. passerinus productivity. Low vegetative cover and deeper water were associated with lower predation rates, suggesting that predation could be a primary factor driving habitat selection patterns. Parrotlets also demonstrated directional dispersal. Pairs that changed nest sites were more likely to disperse from poor-quality nest sites to high-quality nest sites rather than vice versa, and juveniles were more likely to disperse to, or remain in, the more productive of the two local populations. Parrotlets exhibited three characteristics fundamental to the IFD: habitat heterogeneity within and between local populations, reliable habitat cues to productivity, and active dispersal to sites of higher fitness.
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Affiliation(s)
- Timothy C Bonebrake
- Ecosystem Sciences Division, Department of Environmental Science, Policy, and Management, University of California, 37 Mulford Hall, Berkeley, CA 94720-3114, USA.
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Kempf F, Boulinier T, De Meeûs T, Arnathau C, McCoy KD. Recent evolution of host-associated divergence in the seabird tick Ixodes uriae. Mol Ecol 2009; 18:4450-62. [PMID: 19793353 DOI: 10.1111/j.1365-294x.2009.04356.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Ecological interactions are an important source of rapid evolutionary change and thus may generate a significant portion of novel biodiversity. Such changes may be particularly prevalent in parasites, where hosts can induce strong selection for adaptation. To understand the relative frequency at which host-associated divergences occur, it is essential to examine the evolutionary history of the divergence process, particularly when it is occurring over large geographical scales where both geographical and host-associated isolation may playa part. In this study, we use population genetics and phylogeography to study the evolutionary history of host-associated divergence in the seabird tick Ixodes uriae (Acari, Ixodidae). We compare results from microsatellite markers that reflect more ecological timescales with a conserved mitochondrial gene (COIII) that reflects more ancient divergence events. Population structure based on microsatellites showed clear evidence of host-associated divergence in all colonies examined. However, isolated populations of the same host type did not always group together in overall analyses and the genetic differentiation among sympatric host races was highly variable. In contrast, little host or geographical structure was found for the mitochondrial gene fragment. These results suggest that host race formation in I. uriae is a recent phenomenon, that it may have occurred several times and that local interactions are at different points in the divergence process. Rapid divergence in I. uriae implies a strong interaction with its local host species, an interaction that will alter the ecological dynamics of the system and modify the epidemiological landscape of circulating micropathogens.
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Affiliation(s)
- Florent Kempf
- Génétique et Evolution des Maladies Infectieuses, UMR CNRS-IRD 2724, IRD, BP 64501, 34394 Montpellier Cedex 5, France.
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