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Bond ML, Lee DE, Paniw M. Extinction risks and mitigation for a megaherbivore, the giraffe, in a human-influenced landscape under climate change. GLOBAL CHANGE BIOLOGY 2023; 29:6693-6712. [PMID: 37819148 DOI: 10.1111/gcb.16970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 09/20/2023] [Accepted: 09/20/2023] [Indexed: 10/13/2023]
Abstract
Megaherbivores play "outsized" roles in ecosystem functioning but are vulnerable to human impacts such as overhunting, land-use changes, and climate extremes. However, such impacts-and combinations of these impacts-on population dynamics are rarely examined using empirical data. To guide effective conservation actions under increasing global-change pressures, we developed a socially structured individual-based model (IBM) using long-term demographic data from female giraffes (Giraffa camelopardalis) in a human-influenced landscape in northern Tanzania, the Tarangire Ecosystem. This unfenced system includes savanna habitats with a wide gradient of anthropogenic pressures, from national parks, a wildlife ranch and community conservation areas, to unprotected village lands. We then simulated and projected over 50 years how realistic environmental and land-use management changes might affect this metapopulation of female giraffes. Scenarios included: (1) anthropogenic land-use changes including roads and agricultural/urban expansion; (2) reduction or improvement in wildlife law enforcement measures; (3) changes in populations of natural predators and migratory alternative prey; and (4) increases in rainfall as predicted for East Africa. The factor causing the greatest risk of rapid declines in female giraffe abundance in our simulations was a reduction in law enforcement leading to more poaching. Other threats decreased abundances of giraffes, but improving law enforcement in both of the study area's protected areas mitigated these impacts: a 0.01 increase in giraffe survival probability from improved law enforcement mitigated a 25% rise in heavy rainfall events by increasing abundance 19%, and mitigated the expansion of towns and blockage of dispersal movements by increasing abundance 22%. Our IBM enabled us to further quantify fine-scale abundance changes among female giraffe social communities, revealing potential source-sink interactions within the metapopulation. This flexible methodology can be adapted to test additional ecological questions in this landscape, or to model populations of giraffes or other species in different ecosystems.
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Affiliation(s)
- Monica L Bond
- Department of Conservation Biology, Estación Biológica de Doñana (EBD-CSIC), Seville, Spain
- Wild Nature Institute, Concord, New Hampshire, USA
| | - Derek E Lee
- Wild Nature Institute, Concord, New Hampshire, USA
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Maria Paniw
- Department of Conservation Biology, Estación Biológica de Doñana (EBD-CSIC), Seville, Spain
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2
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Rödel HG, Ibler B, Ozogány K, Kerekes V. Age-specific effects of density and weather on body condition and birth rates in a large herbivore, the Przewalski's horse. Oecologia 2023; 203:435-451. [PMID: 37971561 PMCID: PMC10684615 DOI: 10.1007/s00442-023-05477-9] [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: 05/30/2023] [Accepted: 11/05/2023] [Indexed: 11/19/2023]
Abstract
Reproduction in young females can show a particularly sensitive response to environmental challenges, although empirical support from individual-based long-term studies is scarce. Based on a 20-year data set from a free-roaming Przewalski's horse population (Equus ferus przewalskii), we studied effects of large-herbivore density (horses + cattle) and weather conditions experienced during different life stages on females' annual birth rates. Foaling probability was very low in 2-year-olds, reaching maximum values in 5 to 10-year-olds, followed by a decrease in older females indicating reproductive senescence. Mother's previous reproductive investment affected her current reproduction; young and old mothers (as opposed to middle-aged ones), which had nursed a foal for at least 60 days during the previous year, reproduced with a lower probability. Foaling probability and body condition of young females were lower when large-herbivore density was high. Reproduction was also influenced by interactive weather effects during different life stages. Low late-summer precipitation during the females' year of birth was associated with a pronounced decrease in foaling probability in response to harsh late-winter temperatures prior to the mating season. In turn, increased amounts of late-summer rain during this early age together with more late-summer rain during the females' current pregnancy led to an increased reproductive probability in 2-3-year-olds. These results were corroborated by the ameliorating effects of late-summer rain on body condition in such females. In conclusion, our findings highlight the interactive importance of weather conditions experienced during early life, and of density and weather during current pregnancy on foaling probability, particularly in young females.
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Affiliation(s)
- Heiko G Rödel
- Laboratoire d'Ethologie Expérimentale et Comparée UR 4443 (LEEC), Université Sorbonne Paris Nord, 93430, Villetaneuse, France.
| | - Benjamin Ibler
- Heimat-Tierpark Olderdissen (Bielefeld Zoo), Dornberger Straße 149a, 33619, Bielefeld, Germany
| | - Katalin Ozogány
- HUN-REN-UD Behavioural Ecology Research Group, University of Debrecen, Egyetem tér 1, 4032, Debrecen, Hungary
- Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egyetem tér 1, 4032, Debrecen, Hungary
| | - Viola Kerekes
- Department of Evolutionary Zoology and Human Biology, University of Debrecen, Egyetem tér 1, 4032, Debrecen, Hungary.
- Hortobágy National Park Directorate, Sumen utca. 2, 4024, Debrecen, Hungary.
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3
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Larios L, Hallett LM. Incorporating temporal dynamics to enhance grazing management outcomes for a long‐lived species. J Appl Ecol 2022. [DOI: 10.1111/1365-2664.14283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Loralee Larios
- Department of Botany and Plant Sciences University of California Riverside CA USA
| | - Lauren M. Hallett
- Department of Biology and Environmental Studies Program University of Oregon Eugene OR USA
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4
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Healy BD, Budy P, Conner MM, Omana Smith EC. Life and death in a dynamic environment: Invasive trout, floods, and intraspecific drivers of translocated populations. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022. [PMID: 35403769 DOI: 10.6084/m9.figshare.c.5805593.v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Understanding the relative strengths of intrinsic and extrinsic factors regulating populations is a long-standing focus of ecology and critical to advancing conservation programs for imperiled species. Conservation could benefit from an increased understanding of factors influencing vital rates (somatic growth, recruitment, survival) in small, translocated populations, which is lacking owing to difficulties in long-term monitoring of rare species. Translocations, here defined as the transfer of wild-captured individuals from source populations to new habitats, are widely used for species conservation, but outcomes are often minimally monitored, and translocations that are monitored often fail. To improve our understanding of how translocated populations respond to environmental variation, we developed and tested hypotheses related to intrinsic (density dependent) and extrinsic (introduced rainbow trout Oncorhynchus mykiss, stream flow and temperature regime) causes of vital rate variation in endangered humpback chub (Gila cypha) populations translocated to Colorado River tributaries in the Grand Canyon (GC), USA. Using biannual recapture data from translocated populations over 10 years, we tested hypotheses related to seasonal somatic growth, and recruitment and population growth rates with linear mixed-effects models and temporal symmetry mark-recapture models. We combined data from recaptures and resights of dispersed fish (both physical captures and continuously recorded antenna detections) from throughout GC to test survival hypotheses, while accounting for site fidelity, using joint live-recapture/live-resight models. While recruitment only occurred in one site, which also drove population growth (relative to survival), evidence supported hypotheses related to density dependence in growth, survival, and recruitment, and somatic growth and recruitment were further limited by introduced trout. Mixed-effects models explained between 67% and 86% of the variation in somatic growth, which showed increased growth rates with greater flood-pulse frequency during monsoon season. Monthly survival was 0.56-0.99 and 0.80-0.99 in the two populations, with lower survival during periods of higher intraspecific abundance and low flood frequency. Our results suggest translocations can contribute toward the recovery of large-river fishes, but continued suppression of invasive fishes to enhance recruitment may be required to ensure population resilience. Furthermore, we demonstrate the importance of flooding to population demographics in food-depauperate, dynamic, invaded systems.
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Affiliation(s)
- Brian D Healy
- Department of Watershed Sciences and the Ecology Center, Utah State University, Logan, Utah, USA
- Native Fish Ecology and Conservation Program, Division of Science and Resource Management, Grand Canyon National Park, National Park Service, Flagstaff, Arizona, USA
| | - Phaedra Budy
- Department of Watershed Sciences and the Ecology Center, Utah State University, Logan, Utah, USA
- United States Geological Survey, Utah Cooperative Fish and Wildlife Research Unit, Department of Watershed Sciences, Utah State University, Logan, Utah, USA
| | - Mary M Conner
- Department of Wildland Resources and the Ecology Center, Utah State University, Logan, Utah, USA
| | - Emily C Omana Smith
- Native Fish Ecology and Conservation Program, Division of Science and Resource Management, Grand Canyon National Park, National Park Service, Flagstaff, Arizona, USA
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5
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Healy BD, Budy P, Conner MM, Omana Smith EC. Life and death in a dynamic environment: Invasive trout, floods, and intraspecific drivers of translocated populations. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2635. [PMID: 35403769 PMCID: PMC9541007 DOI: 10.1002/eap.2635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 01/25/2022] [Accepted: 02/24/2022] [Indexed: 05/14/2023]
Abstract
Understanding the relative strengths of intrinsic and extrinsic factors regulating populations is a long-standing focus of ecology and critical to advancing conservation programs for imperiled species. Conservation could benefit from an increased understanding of factors influencing vital rates (somatic growth, recruitment, survival) in small, translocated populations, which is lacking owing to difficulties in long-term monitoring of rare species. Translocations, here defined as the transfer of wild-captured individuals from source populations to new habitats, are widely used for species conservation, but outcomes are often minimally monitored, and translocations that are monitored often fail. To improve our understanding of how translocated populations respond to environmental variation, we developed and tested hypotheses related to intrinsic (density dependent) and extrinsic (introduced rainbow trout Oncorhynchus mykiss, stream flow and temperature regime) causes of vital rate variation in endangered humpback chub (Gila cypha) populations translocated to Colorado River tributaries in the Grand Canyon (GC), USA. Using biannual recapture data from translocated populations over 10 years, we tested hypotheses related to seasonal somatic growth, and recruitment and population growth rates with linear mixed-effects models and temporal symmetry mark-recapture models. We combined data from recaptures and resights of dispersed fish (both physical captures and continuously recorded antenna detections) from throughout GC to test survival hypotheses, while accounting for site fidelity, using joint live-recapture/live-resight models. While recruitment only occurred in one site, which also drove population growth (relative to survival), evidence supported hypotheses related to density dependence in growth, survival, and recruitment, and somatic growth and recruitment were further limited by introduced trout. Mixed-effects models explained between 67% and 86% of the variation in somatic growth, which showed increased growth rates with greater flood-pulse frequency during monsoon season. Monthly survival was 0.56-0.99 and 0.80-0.99 in the two populations, with lower survival during periods of higher intraspecific abundance and low flood frequency. Our results suggest translocations can contribute toward the recovery of large-river fishes, but continued suppression of invasive fishes to enhance recruitment may be required to ensure population resilience. Furthermore, we demonstrate the importance of flooding to population demographics in food-depauperate, dynamic, invaded systems.
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Affiliation(s)
- Brian D. Healy
- Department of Watershed Sciences and the Ecology CenterUtah State UniversityLoganUtahUSA
- Native Fish Ecology and Conservation Program, Division of Science and Resource ManagementGrand Canyon National Park, National Park ServiceFlagstaffArizonaUSA
| | - Phaedra Budy
- Department of Watershed Sciences and the Ecology CenterUtah State UniversityLoganUtahUSA
- United States Geological Survey, Utah Cooperative Fish and Wildlife Research Unit, Department of Watershed SciencesUtah State UniversityLoganUtahUSA
| | - Mary M. Conner
- Department of Wildland Resources and the Ecology CenterUtah State UniversityLoganUtahUSA
| | - Emily C. Omana Smith
- Native Fish Ecology and Conservation Program, Division of Science and Resource ManagementGrand Canyon National Park, National Park ServiceFlagstaffArizonaUSA
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6
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Wightman NE, Howe E, Satura A, Northrup JM. Factors affecting age at primiparity in black bears. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Noah E. Wightman
- Biology Department Trent University 2140 East Bank Drive Peterborough Ontario K9L 1Z8 Canada
| | - Eric Howe
- Ontario Ministry of Northern Development, Mines Natural Resources and Forestry 2140 East Bank Drive Peterborough Ontario K9L 1Z8 Canada
| | - Abbygail Satura
- Ontario Ministry of Northern Development, Mines Natural Resources and Forestry 2140 East Bank Drive Peterborough Ontario K9L 1Z8 Canada
| | - Joseph M. Northrup
- Ontario Ministry of Northern Development, Mines Natural Resources and Forestry 2140 East Bank Drive Peterborough Ontario K9L 1Z8 Canada
- Environmental and Life Sciences Graduate Program Trent University 2140 East Bank Drive Peterborough Ontario K9L 1Z8 Canada
- IUCN Bear Specialist Group‐member North American Bears Expert Team
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7
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Busana M, Childs DZ, Burke TA, Komdeur J, Richardson DS, Dugdale HL. Population level consequences of facultatively cooperative behaviour in a stochastic environment. J Anim Ecol 2021; 91:224-240. [PMID: 34704272 PMCID: PMC9299144 DOI: 10.1111/1365-2656.13618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 10/14/2021] [Indexed: 11/27/2022]
Abstract
The social environment in which individuals live affects their fitness and in turn population dynamics as a whole. Birds with facultative cooperative breeding can live in social groups with dominants, subordinate helpers that assist with the breeding of others, and subordinate non-helpers. Helping behaviour benefits dominants through increased reproductive rates and reduced extrinsic mortality, such that cooperative breeding might have evolved in response to unpredictable, harsh conditions affecting reproduction and/or survival of the dominants. Additionally, there may be different costs and benefits to both helpers and non-helpers, depending on the time-scale. For example, early-life costs might be compensated by later-life benefits. These differential effects are rarely analysed in the same study. We examined whether helping behaviour affects population persistence in a stochastic environment and whether there are direct fitness consequences of different life-history tactics adopted by helpers and non-helpers. We parameterised a matrix population model describing the population dynamics of female Seychelles warblers Acrocephalus sechellensis, birds that display facultative cooperative breeding. The stochastic density-dependent model is defined by a (st)age structure that includes life-history differences between helpers and non-helpers and thus can estimate the demographic mechanisms of direct benefits of helping behaviour. We found that population dynamics are strongly influenced by stochastic variation in the reproductive rates of the dominants, that helping behaviour promotes population persistence and that there are only early-life differences in the direct fitness of helpers and non-helpers. Through a matrix population model, we captured multiple demographic rates simultaneously and analysed their relative importance in determining population dynamics of these cooperative breeders. Disentangling early-life versus lifetime effects of individual tactics sheds new light on the costs and benefits of helping behaviour. For example, the finding that helpers and non-helpers have similar lifetime reproductive outputs and that differences in reproductive values between the two life-history tactics arise only in early life suggests that overall, helpers and non-helpers have a similar balance of costs and benefits when analysing direct benefits. We recommend analysing the consequence of different life-history tactics, during both early life and over the lifetime, as analyses of these different time frames may produce conflicting results.
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Affiliation(s)
- Michela Busana
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Dylan Z Childs
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Terrence A Burke
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Jan Komdeur
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - David S Richardson
- School of Biological Sciences, University of East-Anglia, Norfolk, UK.,Nature Seychelles, Mahè, Republic of Seychelles
| | - Hannah L Dugdale
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.,School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
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8
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Long C, Tordiffe A, Sauther M, Cuozzo F, Millette J, Ganswindt A, Scheun J. Seasonal drivers of faecal glucocorticoid metabolite concentrations in an African strepsirrhine primate, the thick-tailed greater galago ( Otolemur crassicaudatus). CONSERVATION PHYSIOLOGY 2021; 9:coab081. [PMID: 34707874 PMCID: PMC8543700 DOI: 10.1093/conphys/coab081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/14/2021] [Accepted: 09/30/2021] [Indexed: 06/13/2023]
Abstract
As global non-human primate populations show dramatic declines due to climate change, land transformation and other anthropogenic stressors, it has become imperative to study physiological responses to environmental change in order to understand primate adaptability and enhance species conservation strategies. We examined the effects of seasonality on faecal glucocorticoid metabolite (fGCM) concentrations of free-ranging male and female thick-tailed greater galagos (Otolemur crassicaudatus) in an Afromontane habitat. To do so, we established an enzyme immunoassay (EIA) for monitoring fGCM concentrations in the species using a biological validation. Following this, faecal samples were collected each month over the course of a year from free-ranging males and females situated in the Soutpansberg Mountains, Limpopo, South Africa. Multivariate analyses revealed lactation period was a driver of fGCM levels, whereas sex and food availability mostly influenced seasonal fGCM concentrations in the total population. Thus far, the results of this study show that drivers of fGCM levels, an indication of increased adrenocortical activity, in O. crassicaudatus are numerous and complex within the natural environment. The species may be adapted to such conditions and an extreme change to any one component may result in elevated fGCM levels. This increases our understanding of strepsirrhine primate physiology and offers initial insights into species adaptability to a challenging environment.
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Affiliation(s)
- Channen Long
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110, South Africa
- National Zoological Garden, South African National Biodiversity Institute, Pretoria, 0001, South Africa
| | - Adrian Tordiffe
- Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110, South Africa
| | - Michelle Sauther
- Department of Anthropology, University of Colorado, Boulder, CO 80309, USA
| | - Frank Cuozzo
- Lajuma Research Centre, Louis Trichardt (Makhado), 0920, South Africa
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 0028, South Africa
| | - James Millette
- Department of Anthropology, University of Colorado, Boulder, CO 80309, USA
| | - Andre Ganswindt
- National Zoological Garden, South African National Biodiversity Institute, Pretoria, 0001, South Africa
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 0028, South Africa
| | - Juan Scheun
- National Zoological Garden, South African National Biodiversity Institute, Pretoria, 0001, South Africa
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, 0028, South Africa
- Department of Life and Consumer Sciences, University of South Africa, Johannesburg, 1710, South Africa
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9
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Saunders SP, Piper W, Farr MT, Bateman BL, Michel NL, Westerkam H, Wilsey CB. Interrelated impacts of climate and land-use change on a widespread waterbird. J Anim Ecol 2021; 90:1165-1176. [PMID: 33754380 DOI: 10.1111/1365-2656.13444] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 02/02/2021] [Indexed: 11/27/2022]
Abstract
Together climate and land-use change play a crucial role in determining species distribution and abundance, but measuring the simultaneous impacts of these processes on current and future population trajectories is challenging due to time lags, interactive effects and data limitations. Most approaches that relate multiple global change drivers to population changes have been based on occurrence or count data alone. We leveraged three long-term (1995-2019) datasets to develop a coupled integrated population model-Bayesian population viability analysis (IPM-BPVA) to project future survival and reproductive success for common loons Gavia immer in northern Wisconsin, USA, by explicitly linking vital rates to changes in climate and land use. The winter North Atlantic Oscillation (NAO), a broad-scale climate index, immediately preceding the breeding season and annual changes in developed land cover within breeding areas both had strongly negative influences on adult survival. Local summer rainfall was negatively related to fecundity, though this relationship was mediated by a lagged interaction with the winter NAO, suggesting a compensatory population-level response to climate variability. We compared population viability under 12 future scenarios of annual land-use change, precipitation and NAO conditions. Under all scenarios, the loon population was expected to decline, yet the steepest declines were projected under positive NAO trends, as anticipated with ongoing climate change. Thus, loons breeding in the northern United States are likely to remain affected by climatic processes occurring thousands of miles away in the North Atlantic during the non-breeding period of the annual cycle. Our results reveal that climate and land-use changes are differentially contributing to loon population declines along the southern edge of their breeding range and will continue to do so despite natural compensatory responses. We also demonstrate that concurrent analysis of multiple data types facilitates deeper understanding of the ecological implications of anthropogenic-induced change occurring at multiple spatial scales. Our modelling approach can be used to project demographic responses of populations to varying environmental conditions while accounting for multiple sources of uncertainty, an increasingly pressing need in the face of unprecedented global change.
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Affiliation(s)
| | - Walter Piper
- Schmid College of Science & Technology, Chapman University, Orange, CA, USA
| | - Matthew T Farr
- Department of Integrative Biology, Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, MI, USA
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10
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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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11
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Milligan MC, Berkeley LI, McNew LB. Survival of Sharp‐Tailed Grouse Under Variable Livestock Grazing Management. J Wildl Manage 2020. [DOI: 10.1002/jwmg.21909] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Megan C. Milligan
- Department of Animal and Range SciencesMontana State University 103 Animal Biosciences Building Bozeman MT 59717‐2900 USA
| | - Lorelle I. Berkeley
- Wildlife Division, Montana Department of Fish Wildlife, and Parks, P.O. Box 200701 Helena MT 59601 USA
| | - Lance B. McNew
- Department of Animal and Range SciencesMontana State University 103 Animal Biosciences Building Bozeman MT 59717‐2900 USA
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12
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The Demographic Buffering Hypothesis: Evidence and Challenges. Trends Ecol Evol 2020; 35:523-538. [PMID: 32396819 DOI: 10.1016/j.tree.2020.02.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 01/27/2020] [Accepted: 02/06/2020] [Indexed: 11/20/2022]
Abstract
In (st)age-structured populations, the long-run population growth rate is negatively affected by temporal variation in vital rates. In most cases, natural selection should minimize temporal variation in the vital rates to which the long-run population growth is most sensitive, resulting in demographic buffering. By reviewing empirical studies on demographic buffering in wild populations, we found overall support for this hypothesis. However, we also identified issues when testing for demographic buffering. In particular, solving scaling problems for decomposing, measuring, and comparing stochastic variation in vital rates and accounting for density dependence are required in future tests of demographic buffering. In the current context of climate change, demographic buffering may mitigate the negative impact of environmental variation and help populations to persist in an increasingly variable environment.
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13
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Modelling pest dynamics under uncertainty in pest detection: the case of the red palm weevil. Biol Invasions 2020. [DOI: 10.1007/s10530-020-02208-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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14
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Smout S, King R, Pomeroy P. Environment-sensitive mass changes influence breeding frequency in a capital breeding marine top predator. J Anim Ecol 2019; 89:384-396. [PMID: 31749170 DOI: 10.1111/1365-2656.13128] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/23/2019] [Indexed: 01/21/2023]
Abstract
The trade-off between survival and reproduction in resource-limited iteroparous animals can result in some individuals missing some breeding opportunities. In practice, even with the best observation regimes, deciding whether 'missed' years represent real pauses in breeding or failures to detect breeding can be difficult, posing problems for the estimation of individual reproductive output and overall population fecundity. We corrected fecundity estimates by determining whether breeding had occurred in skipped years, using long-term capture-recapture observation datasets with parallel longitudinal mass measurements, based on informative underlying relationships between individuals' mass, breeding status and environmental drivers in a capital breeding phocid, the grey seal. Bayesian modelling considered interacting processes jointly: temporal changes in a phenotypic covariate (mass); relationship of mass to breeding probability; effects of maternal breeding state and mark type on resighting. Full reproductive histories were imputed, with the status of unobserved animals estimated as breeding or non-breeding, accounting for local environmental variation. Overall fecundity was then derived for Scottish breeding colonies with contrasting pup production trends. Maternal mass affected breeding likelihood. Mothers with low body mass at the end of breeding were less likely to bear a pup the following year. Successive breeding episodes incurred a cost in reduced body mass which was more pronounced for North Rona, Outer Hebrides (NR) mothers. Skipping breeding increased subsequent pupping probability substantially for low mass females. Poor environmental conditions were associated with declines in breeding probability at both colonies. Seal mass gain between breeding seasons was (a) negatively associated with lagged North Atlantic Oscillation for seals at NR and (b) positively associated with an index of seal prey (Ammodytes spp) abundance at Isle of May, Firth of Forth (IM). Overall fecundity was marginally greater at IM (increasing/stable pup production) than at NR (decreasing). No effects of mass were detected on maternal survival. Skipping breeding in female grey seals appears to be an individual mass-dependent constraint moderated by previous reproductive output and local environmental conditions. Different demographic trends at breeding colonies were consistent with the fecundities estimated using this method, which is general and adaptable to other situations.
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Affiliation(s)
| | - Ruth King
- School of Mathematics, University of Edinburgh, James Clark Maxwell Building, The King's Buildings, Edinburgh, UK
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15
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Champagnon J, Lebreton JD, Drummond H, Anderson DJ. Pacific Decadal and El Niño oscillations shape survival of a seabird. Ecology 2019; 99:1063-1072. [PMID: 29714830 DOI: 10.1002/ecy.2179] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 01/18/2018] [Accepted: 01/25/2018] [Indexed: 11/11/2022]
Abstract
Understanding and modeling population change is urgently needed to predict effects of climate change on biodiversity. High trophic-level organisms are influenced by fluctuations of prey quality and abundance, which themselves may depend on climate oscillations. Modeling effects of such fluctuations is challenging because prey populations may vary with multiple climate oscillations occurring at different time scales. The analysis of a 28-yr time series of capture-recapture data of a tropical seabird, the Nazca Booby (Sula granti), in the Galápagos, Ecuador, allowed us to test for demographic effects of two major ocean oscillations occurring at distinct time-scales: the inter-annual El Niño Southern Oscillation (ENSO) and inter-decadal oscillations. As expected for a tropical seabird, survival of fledgling birds was highly affected by extreme ENSO events; by contrast, neither recruitment nor breeding participation were affected by either ENSO or decadal oscillations. More interesting, adult survival, a demographic trait that canalizes response to environmental variations, was unaffected by inter-annual ENSO oscillations yet was shaped by the Pacific Decadal Oscillation and small pelagic fish regime. Adult survival decreased during oceanic conditions associated with higher breeding success, an association probably mediated in this species by costs of reproduction that reduce survival when breeding attempts end later. To our knowledge, this is the first study suggesting that survival of a vertebrate can be vulnerable to a natural multidecadal oscillation.
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Affiliation(s)
- Jocelyn Champagnon
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, AP 70275, México DF, 04510, México.,CEFE UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919 Route de Mende, 34293, Montpellier, France.,Institut de Recherche de la Tour du Valat, Le Sambuc, 13200, Arles, France
| | - Jean-Dominique Lebreton
- CEFE UMR 5175, CNRS, Université de Montpellier, Université Paul-Valéry Montpellier, EPHE, 1919 Route de Mende, 34293, Montpellier, France
| | - Hugh Drummond
- Departamento de Ecología Evolutiva, Instituto de Ecología, Universidad Nacional Autónoma de México, AP 70275, México DF, 04510, México
| | - David J Anderson
- Department of Biology, Wake Forest University, Winston-Salem, North Carolina, 27109, USA
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16
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Millon A, Lambin X, Devillard S, Schaub M. Quantifying the contribution of immigration to population dynamics: a review of methods, evidence and perspectives in birds and mammals. Biol Rev Camb Philos Soc 2019; 94:2049-2067. [DOI: 10.1111/brv.12549] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 07/10/2019] [Accepted: 07/17/2019] [Indexed: 02/04/2023]
Affiliation(s)
- Alexandre Millon
- Aix Marseille Université, CNRS, IRD, Avignon Université, IMBE, Institut Méditerranéen de Biodiversité et d'Ecologie marine et continentale, Technopôle Arbois‐Méditerranée, Bât. Villemin – BP 80 F‐13545 Aix‐en‐Provence cedex 04 France
| | - Xavier Lambin
- School of Biological SciencesUniversity of Aberdeen Tillydrone Avenue, Zoology Building, University of Aberdeen, AB24 2TZ Aberdeen U.K
| | - Sébastien Devillard
- Université de Lyon, Université Claude Bernard Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Evolutive F‐69100 Villeurbanne France
| | - Michael Schaub
- Swiss Ornithological Institute Seerose 1, 6204 Sempach Switzerland
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17
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Kadin M, Frederiksen M, Niiranen S, Converse SJ. Linking demographic and food-web models to understand management trade-offs. Ecol Evol 2019; 9:8587-8600. [PMID: 31410264 PMCID: PMC6686646 DOI: 10.1002/ece3.5385] [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: 02/27/2019] [Revised: 05/13/2019] [Accepted: 05/18/2019] [Indexed: 11/17/2022] Open
Abstract
Alternatives in ecosystem-based management often differ with respect to trade-offs between ecosystem values. Ecosystem or food-web models and demographic models are typically employed to evaluate alternatives, but the approaches are rarely integrated to uncover conflicts between values. We applied multistate models to a capture-recapture dataset on common guillemots Uria aalge breeding in the Baltic Sea to identify factors influencing survival. The estimated relationships were employed together with Ecopath-with-Ecosim food-web model simulations to project guillemot survival under six future scenarios incorporating climate change. The scenarios were based on management alternatives for eutrophication and cod fisheries, issues considered top priority for regional management, but without known direct effects on the guillemot population. Our demographic models identified prey quantity (abundance and biomass of sprat Sprattus sprattus) as the main factor influencing guillemot survival. Most scenarios resulted in projections of increased survival, in the near (2016-2040) and distant (2060-2085) future. However, in the scenario of reduced nutrient input and precautionary cod fishing, guillemot survival was projected to be lower in both future periods due to lower sprat stocks. Matrix population models suggested a substantial decline of the guillemot population in the near future, 24% per 10 years, and a smaller reduction, 1.1% per 10 years, in the distant future. To date, many stakeholders and Baltic Sea governments have supported reduced nutrient input and precautionary cod fishing and implementation is underway. Negative effects on nonfocal species have previously not been uncovered, but our results show that the scenario is likely to negatively impact the guillemot population. Linking model results allowed identifying trade-offs associated with management alternatives. This information is critical to thorough evaluation by decision-makers, but not easily obtained by food-web models or demographic models in isolation. Appropriate datasets are often available, making it feasible to apply a linked approach for better-informed decisions in ecosystem-based management.
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Affiliation(s)
- Martina Kadin
- School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
- Swedish Museum of Natural HistoryStockholmSweden
| | | | - Susa Niiranen
- Stockholm Resilience CentreStockholm UniversityStockholmSweden
| | - Sarah J. Converse
- U.S. Geological SurveyWashington Cooperative Fish and Wildlife Research Unit, School of Environmental and Forest Sciences (SEFS) and School of Aquatic and Fishery Sciences (SAFS)University of WashingtonSeattleWashingtonUSA
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18
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Jansen DYM, Pradel R, Mares R, Doutrelant C, Spottiswoode CN, Covas R, Altwegg R. An integrated population model sheds light on the complex population dynamics of a unique colonial breeder. POPUL ECOL 2019. [DOI: 10.1002/1438-390x.12010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Dorine Y. M. Jansen
- Centre for Statistics in Ecology, Environment and Conservation, Department of Statistical Sciences University of Cape Town Rondebosch South Africa
- Applied Biodiversity Research Division, South African National Biodiversity Institute Claremont South Africa
| | - Roger Pradel
- CEFE, CNRS Université de Montpellier, Université Paul Valéry Montpellier 3, EPHE, IRD Montpellier France
| | - Rafael Mares
- CIBIO Research Centre in Biodiversity and Genetic Resources Vairão Portugal
| | - Claire Doutrelant
- CEFE, CNRS Université de Montpellier, Université Paul Valéry Montpellier 3, EPHE, IRD Montpellier France
- DST‐NRF Centre of Excellence, FitzPatrick Institute of African Ornithology University of Cape Town Rondebosch South Africa
| | - Claire N. Spottiswoode
- DST‐NRF Centre of Excellence, FitzPatrick Institute of African Ornithology University of Cape Town Rondebosch South Africa
- Department of Zoology University of Cambridge Cambridge UK
| | - Rita Covas
- CIBIO Research Centre in Biodiversity and Genetic Resources Vairão Portugal
- DST‐NRF Centre of Excellence, FitzPatrick Institute of African Ornithology University of Cape Town Rondebosch South Africa
| | - Res Altwegg
- Centre for Statistics in Ecology, Environment and Conservation, Department of Statistical Sciences University of Cape Town Rondebosch South Africa
- Applied Biodiversity Research Division, South African National Biodiversity Institute Claremont South Africa
- African Climate and Development Initiative University of Cape Town Rondebosch South Africa
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19
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Tomasek BJ, Burghardt LT, Shriver RK. Filling in the gaps in survival analysis: using field data to infer plant responses to environmental stressors. Ecology 2019; 100:e02778. [PMID: 31168840 DOI: 10.1002/ecy.2778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 01/28/2019] [Accepted: 04/26/2019] [Indexed: 11/11/2022]
Abstract
Elucidating how organismal survival depends on the environment is a core component of ecological and evolutionary research. To reconcile high-frequency covariates with lower-frequency demographic censuses, many statistical tools involve aggregating environmental conditions over long periods, potentially obscuring the importance of fluctuating conditions in driving mortality. Here, we introduce a flexible model designed to infer how survival probabilities depend on changing environmental covariates. Specifically, the model (1) quantifies effects of environmental covariates at a higher frequency than the census intervals, and (2) allows partitioning of environmental drivers of individual survival into acute (short-term) and chronic (accumulated) effects. By applying our method to a long-term observational data set of eight annual plant species, we show we can accurately infer daily survival probabilities as temperature and moisture levels change. Next, we show that a species' water use efficiency, known to mediate annual plant population dynamics, is positively correlated with the importance of "chronic stress" inferred by the model. This suggests that model parameters can reflect underlying physiological mechanisms. This method is also applicable to other binary responses (hatching, phenology) or systems (insects, nestlings). Once known, environmental sensitivities can be used for ecological forecasting even when the frequency or variability of environments are changing.
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Affiliation(s)
- Bradley J Tomasek
- Program in Ecology, Biological Sciences Building, 130 Science Drive, Duke University, Durham, North Carolina, USA.,Nicholas School of the Environment, Duke University, Durham, North Carolina, 27708, USA.,2000 W. Lincoln St. Mount Prospect, IL 60056
| | - Liana T Burghardt
- Department of Biology, Biological Sciences Building, 130 Science Drive, Duke University, Durham, North Carolina, USA.,Department of Plant and Microbial Biology, University of Minnesota, 1479 Gortner Avenue, St. Paul, Minnesota, 55108, USA
| | - Robert K Shriver
- Program in Ecology, Biological Sciences Building, 130 Science Drive, Duke University, Durham, North Carolina, USA.,Department of Biology, Biological Sciences Building, 130 Science Drive, Duke University, Durham, North Carolina, USA
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20
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Kelt DA, Heske EJ, Lambin X, Oli MK, Orrock JL, Ozgul A, Pauli JN, Prugh LR, Sollmann R, Sommer S. Advances in population ecology and species interactions in mammals. J Mammal 2019. [DOI: 10.1093/jmammal/gyz017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
AbstractThe study of mammals has promoted the development and testing of many ideas in contemporary ecology. Here we address recent developments in foraging and habitat selection, source–sink dynamics, competition (both within and between species), population cycles, predation (including apparent competition), mutualism, and biological invasions. Because mammals are appealing to the public, ecological insight gleaned from the study of mammals has disproportionate potential in educating the public about ecological principles and their application to wise management. Mammals have been central to many computational and statistical developments in recent years, including refinements to traditional approaches and metrics (e.g., capture-recapture) as well as advancements of novel and developing fields (e.g., spatial capture-recapture, occupancy modeling, integrated population models). The study of mammals also poses challenges in terms of fully characterizing dynamics in natural conditions. Ongoing climate change threatens to affect global ecosystems, and mammals provide visible and charismatic subjects for research on local and regional effects of such change as well as predictive modeling of the long-term effects on ecosystem function and stability. Although much remains to be done, the population ecology of mammals continues to be a vibrant and rapidly developing field. We anticipate that the next quarter century will prove as exciting and productive for the study of mammals as has the recent one.
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Affiliation(s)
- Douglas A Kelt
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, USA
| | - Edward J Heske
- Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM, USA
| | - Xavier Lambin
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Madan K Oli
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | - John L Orrock
- Department of Integrative Biology, University of Wisconsin, Madison, WI, USA
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Jonathan N Pauli
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI, USA
| | - Laura R Prugh
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA
| | - Rahel Sollmann
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, USA
| | - Stefan Sommer
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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21
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Vincenzi S, Jesenšek D, Crivelli AJ. Estimates of vital rates and predictions of population dynamics change along a long‐term monitoring program. POPUL ECOL 2019. [DOI: 10.1002/1438-390x.1031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Simone Vincenzi
- Institute of Marine SciencesUniversity of California Santa Cruz California
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22
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Badia‐Boher JA, Sanz‐Aguilar A, Riva M, Gangoso L, Overveld T, García‐Alfonso M, Luzardo OP, Suarez‐Pérez A, Donázar JA. Evaluating European
LIFE
conservation projects: Improvements in survival of an endangered vulture. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13350] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jaume Adrià Badia‐Boher
- Animal Demography and Ecology UnitIMEDEA (CSIC‐UIB) Esporles Spain
- Estación Biológica de Doñana Sevilla Spain
- Department of BiologyLund University Lund Sweden
| | - Ana Sanz‐Aguilar
- Animal Demography and Ecology UnitIMEDEA (CSIC‐UIB) Esporles Spain
| | | | - Laura Gangoso
- Estación Biológica de Doñana Sevilla Spain
- Institute for Biodiversity and Ecosystem Dynamics (IBED)University of Amsterdam Amsterdam The Netherlands
| | | | | | - Octavio P. Luzardo
- Toxicology UnitIUIBSLas Palmas de Gran Canaria University Las Palmas de Gran Canaria Spain
- Spanish Biomedical Research Center in Physiopathology of Obesity and Nutrition (CIBERObn) Madrid Spain
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23
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Cheney BJ, Thompson PM, Cordes LS. Increasing trends in fecundity and calf survival of bottlenose dolphins in a marine protected area. Sci Rep 2019; 9:1767. [PMID: 30741983 PMCID: PMC6370779 DOI: 10.1038/s41598-018-38278-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 12/21/2018] [Indexed: 11/09/2022] Open
Abstract
Estimates of temporal variation in demographic rates are critical for identifying drivers of population change and supporting conservation. However, for inconspicuous wide-ranging species, births may be missed and fecundity rates underestimated. We address this issue using photo-identification data and a novel robust design multistate model to investigate changes in bottlenose dolphin fecundity and calf survival. The model allows for uncertainty in breeding status, and seasonal effects. The best model estimated an increase in the proportion of females with newborn calves from 0.16 (95% CI = 0.11-0.24) in 2001 to 0.28 (95% CI = 0.22-0.36) in 2016. First year calf survival also increased over this period from 0.78 (95% CI = 0.53-0.92) to 0.93 (95% CI = 0.82-0.98). Second year calf survival remained lower, but also showed an increase from 0.32 (95% CI = 0.19-0.48) to 0.55 (95% CI = 0.44-0.65). Females with newborn calves had a slightly higher mortality than those with older calves, but further work is required to evaluate potential costs of reproduction. This study presents a rare example of empirical evidence of a positive trend in reproduction and survival for a cetacean population using a Marine Protected Area.
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Affiliation(s)
- Barbara J Cheney
- University of Aberdeen, Institute of Biological and Environmental Science, Lighthouse Field Station, Cromarty, IV11 8YL, UK.
| | - Paul M Thompson
- University of Aberdeen, Institute of Biological and Environmental Science, Lighthouse Field Station, Cromarty, IV11 8YL, UK
| | - Line S Cordes
- Bangor University, School of Ocean Sciences, Menai Bridge, LL59 5AB, UK
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24
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Pacoureau N, Authier M, Delord K, Barbraud C. Population response of an apex Antarctic consumer to its prey and climate fluctuations. Oecologia 2018; 189:279-291. [PMID: 30116877 DOI: 10.1007/s00442-018-4249-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/10/2018] [Indexed: 10/28/2022]
Abstract
A fundamental endeavor in population ecology is to identify the drivers of population dynamics. A few empirical studies included the effect of prey abundance when investigating simultaneously the effects of density-dependence and climate factors on marine top-predator population dynamics. Our aim was to unravel the mechanisms forcing population dynamics of an apex consumer seabird, the south polar skua, using long-term climatic and population time series of the consumer and its prey in Terre Adélie, Antarctica. Influences of density-dependence, climatic factors, and prey abundance with lag effects were tested on the breeding population dynamics with a Bayesian multi-model inference approach. We evidenced a negative trend in breeding population growth rate when density increased. Lagged effects of sea-ice concentration and air temperature in spring and a contemporary effect of prey resources were supported. Remarkably, results outline a reverse response of the south polar skua and one of its main preys to the same environmental factor (sea-ice concentration), suggesting a strong link between skua and penguin dynamics. The causal mechanisms may involve competition for food and space through territorial behavior as well as local climate and prey availability, which probably operate on breeding parameters (breeding propensity, breeding success, or recruitment) rather than on adult survival. Our results provide new insights on the relative importance of factors forcing the population dynamics of an apex consumer including density-dependence, local climate conditions, and direct and indirect effects of prey abundance.
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Affiliation(s)
- Nathan Pacoureau
- Centre d'Études Biologiques de Chizé, UMR-CNRS 7372, 79360, Villiers-en-Bois, France.
| | - Matthieu Authier
- Observatoire PELAGIS, UMS-CNRS 3462, Université de la Rochelle, allée 4 de l'Océan, 17000, La Rochelle, France
| | - Karine Delord
- Centre d'Études Biologiques de Chizé, UMR-CNRS 7372, 79360, Villiers-en-Bois, France
| | - Christophe Barbraud
- Centre d'Études Biologiques de Chizé, UMR-CNRS 7372, 79360, Villiers-en-Bois, France
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25
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Nater CR, van Benthem KJ, Canale CI, Schradin C, Ozgul A. Density feedbacks mediate effects of environmental change on population dynamics of a semidesert rodent. J Anim Ecol 2018; 87:1534-1546. [PMID: 30058150 DOI: 10.1111/1365-2656.12888] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 07/22/2018] [Indexed: 11/29/2022]
Abstract
Population dynamics are the result of an interplay between extrinsic and intrinsic environmental drivers. Predicting the effects of environmental change on wildlife populations therefore requires a thorough understanding of the mechanisms through which different environmental drivers interact to generate changes in population size and structure. In this study, we disentangled the roles of temperature, food availability and population density in shaping short- and long-term population dynamics of the African striped mouse, a small rodent inhabiting a semidesert with high intra- and interannual variation in environmental conditions. We parameterized a female-only stage-structured matrix population model with vital rates depending on temperature, food availability and population density, using monthly mark-recapture data from 1609 mice trapped over 9 years (2005-2014). We then applied perturbation analyses to determine relative strengths and demographic pathways of these drivers in affecting population dynamics. Furthermore, we used stochastic population projections to gain insights into how three different climate change scenarios might affect size, structure and persistence of this population. We identified food availability, acting through reproduction, as the main driver of changes in both short- and long-term population dynamics. This mechanism was mediated by strong density feedbacks, which stabilized the population after high peaks and allowed it to recover from detrimental crashes. Density dependence thus buffered the population against environmental change, and even adverse climate change scenarios were predicted to have little effect on population persistence (extinction risk over 100 years <5%) despite leading to overall lower abundances. Explicitly linking environment-demography relationships to population dynamics allowed us to accurately capture past population dynamics. It further enabled establishing the roles and relative importances of extrinsic and intrinsic environmental drivers, and we conclude that doing this is essential when investigating impacts of climate change on wildlife populations.
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Affiliation(s)
- Chloé R Nater
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, Oslo, Norway
| | - Koen J van Benthem
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Cindy I Canale
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Carsten Schradin
- IPHC, UNISTRA, CNRS, Strasbourg, France.,School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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26
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Kosterman MK, Squires JR, Holbrook JD, Pletscher DH, Hebblewhite M. Forest structure provides the income for reproductive success in a southern population of Canada lynx. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2018; 28:1032-1043. [PMID: 29457298 DOI: 10.1002/eap.1707] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 12/08/2017] [Accepted: 02/05/2018] [Indexed: 06/08/2023]
Abstract
Understanding intrinsic and extrinsic drivers of reproductive success is central to advancing animal ecology and characterizing critical habitat. Unfortunately, much of the work examining drivers of reproductive success is biased toward particular groups of organisms (e.g., colonial birds, large herbivores, capital breeders). Long-lived mammalian carnivores that are of conservation concern, solitary, and territorial present an excellent situation to examine intrinsic and extrinsic drivers of reproductive success, yet they have received little attention. Here, we used a Canada lynx (Lynx canadensis) data set, from the southern periphery of their range, to determine if reproductive success in a solitary carnivore was consistent with capital or income breeding. We radio-marked and monitored 36 female Canada lynx for 98 lynx years. We evaluated how maternal characteristics and indices of food supply (via forest structure) in core areas influenced variation in body condition and reproductive success. We characterized body condition as mass/length and reproductive success as whether a female produced a litter of kittens for a given breeding season. Consistent with life-history theory, we documented a positive effect of maternal age on body condition and reproductive success. In contrast to predictions of capital breeding, we observed no effect of pre-pregnancy body condition on reproductive success in Canada lynx. However, we demonstrated statistical effects of forest structure on reproductive success in Canada lynx, consistent with predictions of income breeding. The forest characteristics that defined high success included (1) abundant and connected mature forest and (2) intermediate amounts of small-diameter regenerating forest. These attributes are consistent with providing abundant, temporally stable, and accessible prey resources (i.e., snowshoe hares; Lepus americanus) for lynx and reinforce the bottom-up mechanisms influencing Canada lynx populations. Collectively, our results suggest that lynx on the southern range periphery exhibit an income breeding strategy and that forest structure supplies the income important for successful reproduction. More broadly, our insights advance the understanding of carnivore ecology and serve as an important example on integrating long-term field studies with ecological theory to improve landscape management.
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Affiliation(s)
- Megan K Kosterman
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, Montana, 59812, USA
| | - John R Squires
- United States Department of Agriculture Forest Service, Rocky Mountain Research Station, 800 E Beckwith, Missoula, Montana, 59801, USA
| | - Joseph D Holbrook
- United States Department of Agriculture Forest Service, Rocky Mountain Research Station, 800 E Beckwith, Missoula, Montana, 59801, USA
- Department of Land Resources and Environmental Sciences, College of Agriculture, Montana State University, P.O. Box 173120, Bozeman, Montana, 59717, USA
| | - Daniel H Pletscher
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, Montana, 59812, USA
| | - Mark Hebblewhite
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation, University of Montana, 32 Campus Drive, Missoula, Montana, 59812, USA
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27
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Vincenzi S, Jesenšek D, Crivelli AJ. A framework for estimating the determinants of spatial and temporal variation in vital rates and inferring the occurrence of unobserved extreme events. ROYAL SOCIETY OPEN SCIENCE 2018; 5:171087. [PMID: 29657746 PMCID: PMC5882670 DOI: 10.1098/rsos.171087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 02/02/2018] [Indexed: 06/08/2023]
Abstract
We develop a general framework that combines long-term tag-recapture data and powerful statistical and modelling techniques to investigate how population, environmental and climate factors determine variation in vital rates and population dynamics in an animal species, using as a case study the population of brown trout living in Upper Volaja (Western Slovenia). This population has been monitored since 2004. Upper Volaja is a sink, receiving individuals from a source population living above a waterfall. We estimate the numerical contribution of the source population on the sink population and test the effects of temperature, population density and extreme events on variation in vital rates among 2647 individually tagged brown trout. We found that individuals dispersing downstream from the source population help maintain high population densities in the sink population despite poor recruitment. The best model of survival for individuals older than juveniles includes additive effects of birth cohort and sampling occasion. Fast growth of older cohorts and higher population densities in 2004-2005 suggest very low population densities in the late 1990s, which we hypothesize were caused by a flash flood that strongly reduced population size and created the habitat conditions for faster individual growth and transient higher population densities after the extreme event.
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Affiliation(s)
- Simone Vincenzi
- Institute of Marine Sciences, University of California, Santa Cruz, CA 95064, USA
| | | | - Alain J. Crivelli
- Station Biologique de la Tour du Valat, Le Sambuc, 13200 Arles, France
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28
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Additive effects of climate and fisheries drive ongoing declines in multiple albatross species. Proc Natl Acad Sci U S A 2017; 114:E10829-E10837. [PMID: 29158390 DOI: 10.1073/pnas.1618819114] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Environmental and anthropogenic factors often drive population declines in top predators, but how their influences may combine remains unclear. Albatrosses are particularly threatened. They breed in fast-changing environments, and their extensive foraging ranges expose them to incidental mortality (bycatch) in multiple fisheries. The albatross community at South Georgia includes globally important populations of three species that have declined by 40-60% over the last 35 years. We used three steps to deeply understand the drivers of such dramatic changes: (i) describe fundamental demographic rates using multievent models, (ii) determine demographic drivers of population growth using matrix models, and (iii) identify environmental and anthropogenic drivers using ANOVAs. Each species was affected by different processes and threats in their foraging areas during the breeding and nonbreeding seasons. There was evidence for two kinds of combined environmental and anthropogenic effects. The first was sequential; in wandering and black-browed albatrosses, high levels of bycatch have reduced juvenile and adult survival, then increased temperature, reduced sea-ice cover, and stronger winds are affecting the population recovery potential. The second was additive; in gray-headed albatrosses, not only did bycatch impact adult survival but also this impact was exacerbated by lower food availability in years following El Niño events. This emphasizes the need for much improved implementation of mitigation measures in fisheries and better enforcement of compliance. We hope our results not only help focus future management actions for these populations but also demonstrate the power of the modelling approach for assessing impacts of environmental and anthropogenic drivers in wild animal populations.
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Campos FA, Morris WF, Alberts SC, Altmann J, Brockman DK, Cords M, Pusey A, Stoinski TS, Strier KB, Fedigan LM. Does climate variability influence the demography of wild primates? Evidence from long-term life-history data in seven species. GLOBAL CHANGE BIOLOGY 2017; 23:4907-4921. [PMID: 28589633 DOI: 10.10.1111/gcb.13754] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 04/04/2017] [Indexed: 05/21/2023]
Abstract
Earth's rapidly changing climate creates a growing need to understand how demographic processes in natural populations are affected by climate variability, particularly among organisms threatened by extinction. Long-term, large-scale, and cross-taxon studies of vital rate variation in relation to climate variability can be particularly valuable because they can reveal environmental drivers that affect multiple species over extensive regions. Few such data exist for animals with slow life histories, particularly in the tropics, where climate variation over large-scale space is asynchronous. As our closest relatives, nonhuman primates are especially valuable as a resource to understand the roles of climate variability and climate change in human evolutionary history. Here, we provide the first comprehensive investigation of vital rate variation in relation to climate variability among wild primates. We ask whether primates are sensitive to global changes that are universal (e.g., higher temperature, large-scale climate oscillations) or whether they are more sensitive to global change effects that are local (e.g., more rain in some places), which would complicate predictions of how primates in general will respond to climate change. To address these questions, we use a database of long-term life-history data for natural populations of seven primate species that have been studied for 29-52 years to investigate associations between vital rate variation, local climate variability, and global climate oscillations. Associations between vital rates and climate variability varied among species and depended on the time windows considered, highlighting the importance of temporal scale in detection of such effects. We found strong climate signals in the fertility rates of three species. However, survival, which has a greater impact on population growth, was little affected by climate variability. Thus, we found evidence for demographic buffering of life histories, but also evidence of mechanisms by which climate change could affect the fates of wild primates.
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Affiliation(s)
- Fernando A Campos
- Department of Anthropology, Tulane University, New Orleans, LA, USA
- Department of Anthropology, University of Calgary, Calgary, AB, Canada
| | | | - Susan C Alberts
- Department of Biology, Duke University, Durham, NC, USA
- Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya
| | - Jeanne Altmann
- Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Diane K Brockman
- Department of Anthropology, University of North Carolina, Charlotte, NC, USA
| | - Marina Cords
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA
| | - Anne Pusey
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Tara S Stoinski
- The Dian Fossey Gorilla Fund International, Atlanta, GA, USA
| | - Karen B Strier
- Department of Anthropology, University of Wisconsin-Madison, Madison, WI, USA
| | - Linda M Fedigan
- Department of Anthropology, University of Calgary, Calgary, AB, Canada
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30
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Campos FA, Morris WF, Alberts SC, Altmann J, Brockman DK, Cords M, Pusey A, Stoinski TS, Strier KB, Fedigan LM. Does climate variability influence the demography of wild primates? Evidence from long-term life-history data in seven species. GLOBAL CHANGE BIOLOGY 2017; 23:4907-4921. [PMID: 28589633 DOI: 10.1111/gcb.13754] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 04/04/2017] [Indexed: 05/22/2023]
Abstract
Earth's rapidly changing climate creates a growing need to understand how demographic processes in natural populations are affected by climate variability, particularly among organisms threatened by extinction. Long-term, large-scale, and cross-taxon studies of vital rate variation in relation to climate variability can be particularly valuable because they can reveal environmental drivers that affect multiple species over extensive regions. Few such data exist for animals with slow life histories, particularly in the tropics, where climate variation over large-scale space is asynchronous. As our closest relatives, nonhuman primates are especially valuable as a resource to understand the roles of climate variability and climate change in human evolutionary history. Here, we provide the first comprehensive investigation of vital rate variation in relation to climate variability among wild primates. We ask whether primates are sensitive to global changes that are universal (e.g., higher temperature, large-scale climate oscillations) or whether they are more sensitive to global change effects that are local (e.g., more rain in some places), which would complicate predictions of how primates in general will respond to climate change. To address these questions, we use a database of long-term life-history data for natural populations of seven primate species that have been studied for 29-52 years to investigate associations between vital rate variation, local climate variability, and global climate oscillations. Associations between vital rates and climate variability varied among species and depended on the time windows considered, highlighting the importance of temporal scale in detection of such effects. We found strong climate signals in the fertility rates of three species. However, survival, which has a greater impact on population growth, was little affected by climate variability. Thus, we found evidence for demographic buffering of life histories, but also evidence of mechanisms by which climate change could affect the fates of wild primates.
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Affiliation(s)
- Fernando A Campos
- Department of Anthropology, Tulane University, New Orleans, LA, USA
- Department of Anthropology, University of Calgary, Calgary, AB, Canada
| | | | - Susan C Alberts
- Department of Biology, Duke University, Durham, NC, USA
- Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya
| | - Jeanne Altmann
- Institute of Primate Research, National Museums of Kenya, Nairobi, Kenya
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Diane K Brockman
- Department of Anthropology, University of North Carolina, Charlotte, NC, USA
| | - Marina Cords
- Department of Ecology, Evolution and Environmental Biology, Columbia University, New York, NY, USA
| | - Anne Pusey
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Tara S Stoinski
- The Dian Fossey Gorilla Fund International, Atlanta, GA, USA
| | - Karen B Strier
- Department of Anthropology, University of Wisconsin-Madison, Madison, WI, USA
| | - Linda M Fedigan
- Department of Anthropology, University of Calgary, Calgary, AB, Canada
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31
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Eriksen LF, Moa PF, Nilsen EB. Quantifying risk of overharvest when implementation is uncertain. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.12992] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lasse F. Eriksen
- Faculty of Biosciences and Aquaculture; Nord University; Steinkjer Norway
- Department of Terrestrial Ecology; Norwegian Institute for Nature Research; Trondheim Norway
- Faculty of Applied Ecology and Agricultural Sciences; Inland Norway University of Applied Sciences; Elverum Norway
| | - Pål F. Moa
- Faculty of Biosciences and Aquaculture; Nord University; Steinkjer Norway
| | - Erlend B. Nilsen
- Department of Terrestrial Ecology; Norwegian Institute for Nature Research; Trondheim Norway
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32
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Winder VL, McNew LB, Pitman JC, Sandercock BK. Effects of rangeland management on survival of female greater prairie-chickens. J Wildl Manage 2017. [DOI: 10.1002/jwmg.21331] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - Lance B. McNew
- Department of Animal and Range Sciences; Montana State University; Bozeman MT 59717 USA
| | - James C. Pitman
- Kansas Department of Wildlife, Parks & Tourism; Emporia KS 66801 USA
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33
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Schofield G, Katselidis KA, Lilley MKS, Reina RD, Hays GC. Detecting elusive aspects of wildlife ecology using drones: New insights on the mating dynamics and operational sex ratios of sea turtles. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12930] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gail Schofield
- Deakin UniversitySchool of Life and Environmental SciencesCentre for Integrative Ecology Warrnambool Vic. Australia
| | | | - Martin K. S. Lilley
- School of Biological and Chemical SciencesQueen Mary University of London London UK
| | - Richard D. Reina
- School of Biological SciencesMonash University Clayton Vic. Australia
| | - Graeme C. Hays
- Deakin UniversitySchool of Life and Environmental SciencesCentre for Integrative Ecology Warrnambool Vic. Australia
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34
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Lester PJ, Haywood J, Archer ME, Shortall CR. The long-term population dynamics of common wasps in their native and invaded range. J Anim Ecol 2017; 86:337-347. [DOI: 10.1111/1365-2656.12622] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 12/02/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Philip J. Lester
- School of Biological Sciences; Victoria University of Wellington; PO Box 600 Wellington New Zealand
| | - John Haywood
- School of Mathematics and Statistics; Victoria University of Wellington; PO Box 600 Wellington New Zealand
| | | | - Chris R. Shortall
- Rothamsted Insect Survey; Department of Agroecology; Rothamsted Research; Harpenden Hertfordshire AL5 2JQ UK
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35
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Plăiaşu R, Ozgul A, Schmidt BR, Băncilă RI. Estimation of apparent survival probability of the harvestman Paranemastoma sillii sillii (Herman, 1871) from two caves. ANIM BIOL 2017. [DOI: 10.1163/15707563-00002529] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Reliable estimates of population parameters are lacking for most cave-dwelling species. This lack of knowledge may hinder the appropriate management of caves and populations of cave-dwelling species. Using monthly capture-recapture data and Cormack-Jolly-Seber models, we (i) estimated the apparent survival of individuals in two cave populations of the harvestman Paranemastoma sillii sillii (Herman, 1871) from the Mehedinti Mountains in south-western Romania; (ii) investigated temporal variation in apparent survival; (iii) tested if surface weather conditions affect apparent survival of cave-dwelling harvestmen through their influence upon cave environmental conditions and (iv) tested for sex differences in apparent survival. Our results show that the apparent monthly survival estimates were high for both studied cave populations and there was a significant sex effect on survival. Males had lower survival than females, and the survival difference between caves was larger in males than in females. Temporal (i.e., monthly) variation in apparent survival was low and the weather conditions at the surface had little influence on apparent survival as the environment inside the caves is well buffered against weather fluctuations outside the caves. Our results indicate that caves stabilize survival of facultative cave-dwelling species and may serve as microrefugia for epigean species. We suggest that caves should be considered for conservation because they may serve as a refuge for some epigean species during harsh weather conditions.
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Affiliation(s)
- Rodica Plăiaşu
- “Emil Racoviţă” Institute of Speleology of Romanian Academy, 13 Septembrie Road, No. 13, 050711 Bucharest, Romania
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Benedikt R. Schmidt
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
- KARCH, Passage Maximilien-de-Meuron 6, CH-2000 Neuchâtel, Switzerland
| | - Raluca I. Băncilă
- “Emil Racoviţă” Institute of Speleology of Romanian Academy, 13 Septembrie Road, No. 13, 050711 Bucharest, Romania
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
- University Ovidius Constanţa, Faculty of Natural Sciences, Al. Universităţii, Corp B, Constanţa, Romania
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36
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Vincenzi S, Mangel M, Jesensˇek D, Garza JC, Crivelli AJ. Within- and among-population variation in vital rates and population dynamics in a variable environment. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:2086-2102. [PMID: 27755735 DOI: 10.1890/15-1808.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 02/25/2016] [Accepted: 03/08/2016] [Indexed: 05/14/2023]
Abstract
Understanding the causes of within- and among-population differences in vital rates, life histories, and population dynamics is a central topic in ecology. To understand how within- and among-population variation emerges, we need long-term studies that include episodic events and contrasting environmental conditions, data to characterize individual and shared variation, and statistical models that can tease apart shared and individual contribution to the observed variation. We used long-term tag-recapture data to investigate and estimate within- and among-population differences in vital rates, life histories, and population dynamics of marble trout Salmo marmoratus, an endemic freshwater salmonid with a narrow range. Only ten populations of pure marble trout persist in headwaters of Alpine rivers in western Slovenia. Marble trout populations are also threatened by floods and landslides, which have already caused the extinction of two populations in recent years. We estimated and determined causes of variation in growth, survival, and recruitment both within and among populations, and evaluated trade-offs between them. Specifically, we estimated the responses of these traits to variation in water temperature, density, sex, early life conditions, and extreme events. We found that the effects of population density on traits were mostly limited to the early stages of life and that growth trajectories were established early in life. We found no clear effects of water temperature on vital rates. Population density varied over time, with flash floods and debris flows causing massive mortalities (>55% decrease in survival with respect to years with no floods) and threatening population persistence. Apart from flood events, variation in population density within streams was largely determined by variation in recruitment, with survival of older fish being relatively constant over time within populations, but substantially different among populations. Marble trout show a fast to slow continuum of life histories, with slow growth associated with higher survival at the population level, possibly determined by food conditions and age at maturity. Our work provides unprecedented insight into the causes of variation in vital rates, life histories, and population dynamics in an endemic species that is teetering on the edge of extinction.
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Affiliation(s)
- Simone Vincenzi
- Department of Applied Mathematics and Statistics, Center for Stock Assessment Research, University of California, 1156 High Street, Santa Cruz, CA, 95064, USA.
- Dipartimento di Elettronica, Informazione e Bioingegneria Politecnico di Milano, Via Ponzio 34/5, I-20133, Milan, Italy.
| | - Marc Mangel
- Department of Applied Mathematics and Statistics, Center for Stock Assessment Research, University of California, 1156 High Street, Santa Cruz, CA, 95064, USA
- Department of Biology, University of Bergen, Bergen, 5020, Norway
| | - Dusˇan Jesensˇek
- Tolmin Angling Association, Trg 1. maja 7, 5220 Tolmin, Slovenia
| | - John C Garza
- Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA and University of California, Santa Cruz 110 Shaffer Rd, Santa Cruz, California, 95060, USA
| | - Alain J Crivelli
- Station Biologique de la Tour du Valat, Le Sambuc, F-13200, Arles, France
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37
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Population viability analysis of plant and animal populations with stochastic integral projection models. Oecologia 2016; 182:1031-1043. [DOI: 10.1007/s00442-016-3704-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 08/10/2016] [Indexed: 10/21/2022]
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38
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Pol M, Bailey LD, McLean N, Rijsdijk L, Lawson CR, Brouwer L. Identifying the best climatic predictors in ecology and evolution. Methods Ecol Evol 2016. [DOI: 10.1111/2041-210x.12590] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Martijn Pol
- Department of Evolution, Ecology & Genetics Research School of Biology The Australian National University Canberra ACT 0200 Australia
- Department of Animal Ecology Netherlands Institute of Ecology (NIOO‐KNAW) Droevendaalsesteeg 10 6708PB Wageningen The Netherlands
- Centre for Avian Population Studies Nijmegen the Netherlands
| | - Liam D. Bailey
- Department of Evolution, Ecology & Genetics Research School of Biology The Australian National University Canberra ACT 0200 Australia
| | - Nina McLean
- Department of Evolution, Ecology & Genetics Research School of Biology The Australian National University Canberra ACT 0200 Australia
| | - Laurie Rijsdijk
- Department of Evolution, Ecology & Genetics Research School of Biology The Australian National University Canberra ACT 0200 Australia
- Department of Animal Ecology Netherlands Institute of Ecology (NIOO‐KNAW) Droevendaalsesteeg 10 6708PB Wageningen The Netherlands
- Department of Animal Ecology and Physiology Radboud University Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Callum R. Lawson
- Department of Animal Ecology Netherlands Institute of Ecology (NIOO‐KNAW) Droevendaalsesteeg 10 6708PB Wageningen The Netherlands
| | - Lyanne Brouwer
- Department of Evolution, Ecology & Genetics Research School of Biology The Australian National University Canberra ACT 0200 Australia
- Department of Animal Ecology Netherlands Institute of Ecology (NIOO‐KNAW) Droevendaalsesteeg 10 6708PB Wageningen The Netherlands
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39
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Gélin U, Coulson G, Festa-Bianchet M. Heterogeneity in reproductive success explained by individual differences in bite rate and mass change. Behav Ecol 2015. [DOI: 10.1093/beheco/arv209] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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40
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Bowlby HD, Gibson AJF. Environmental effects on survival rates: robust regression, recovery planning and endangered Atlantic salmon. Ecol Evol 2015; 5:3450-61. [PMID: 26380677 PMCID: PMC4569039 DOI: 10.1002/ece3.1614] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 06/18/2015] [Accepted: 06/25/2015] [Indexed: 12/03/2022] Open
Abstract
Describing how population-level survival rates are influenced by environmental change becomes necessary during recovery planning to identify threats that should be the focus for future remediation efforts. However, the ways in which data are analyzed have the potential to change our ecological understanding and thus subsequent recommendations for remedial actions to address threats. In regression, distributional assumptions underlying short time series of survival estimates cannot be investigated a priori and data likely contain points that do not follow the general trend (outliers) as well as contain additional variation relative to an assumed distribution (overdispersion). Using juvenile survival data from three endangered Atlantic salmon Salmo salar L. populations in response to hydrological variation, four distributions for the response were compared using lognormal and generalized linear models (GLM). The influence of outliers as well as overdispersion was investigated by comparing conclusions from robust regressions with these lognormal models and GLMs. The analyses strongly supported the use of a lognormal distribution for survival estimates (i.e., modeling the instantaneous rate of mortality as the response) and would have led to ambiguity in the identification of significant hydrological predictors as well as low overall confidence in the predicted relationships if only GLMs had been considered. However, using robust regression to evaluate the effect of additional variation and outliers in the data relative to regression assumptions resulted in a better understanding of relationships between hydrological variables and survival that could be used for population-specific recovery planning. This manuscript highlights how a systematic analysis that explicitly considers what monitoring data represent and where variation is likely to come from is required in order to draw meaningful conclusions when analyzing changes in survival relative to environmental variation to aid in recovery planning.
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Affiliation(s)
- Heather D Bowlby
- Bedford Institute of Oceanography, Fisheries and Oceans, Canada Dartmouth, Nova Scotia, B2Y 4A2, Canada ; Memorial University of Newfoundland, Ocean Sciences Centre St. John's, Newfoundland, A1C 5S7, Canada
| | - A Jamie F Gibson
- Bedford Institute of Oceanography, Fisheries and Oceans, Canada Dartmouth, Nova Scotia, B2Y 4A2, Canada
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41
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Sanz-Aguilar A, Jovani R, Melián CJ, Pradel R, Tella JL. Multi-event capture–recapture analysis reveals individual foraging specialization in a generalist species. Ecology 2015. [DOI: 10.1890/14-0437.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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42
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Szostek KL, Becker PH. Survival and local recruitment are driven by environmental carry-over effects from the wintering area in a migratory seabird. Oecologia 2015; 178:643-57. [PMID: 25864177 DOI: 10.1007/s00442-015-3298-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 03/15/2015] [Indexed: 10/23/2022]
Abstract
We estimated annual apparent survival rates, as well as local recruitment rates in different age groups and for different breeding status in the common tern Sterna hirundo using mark-recapture analysis on a long-term individual-based dataset from a breeding colony in Germany. Strong inter-annual variability in survival rates became apparent, especially in prospectors. Local recruitment also varied strongly between years and age groups. To explain these fluctuations, we linked survival and recruitment estimates to several environmental covariates expected to be limiting during the wintering period and migration, including the global climate indices of North Atlantic Oscillation and Southern Oscillation, fish abundance indices, and marine primary productivity in the West African wintering area. Contrary to expectations, global indices did not seem to be linked strongly to vital rates. Results showed that primary productivity had the strongest effect on annual survival, especially in young and inexperienced individuals. Primary productivity in the wintering area was also strongly associated with the probability of recruitment in the following breeding season, indicating that conditions during winter can have carry-over effects on the life cycle of individuals.
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Affiliation(s)
- K Lesley Szostek
- Institute of Avian Research, Vogelwarte Helgoland, An der Vogelwarte 21, 26386, Wilhelmshaven, Germany,
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43
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Ehrlén J, Morris WF. Predicting changes in the distribution and abundance of species under environmental change. Ecol Lett 2015; 18:303-14. [PMID: 25611188 PMCID: PMC4674973 DOI: 10.1111/ele.12410] [Citation(s) in RCA: 197] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/03/2014] [Accepted: 12/17/2014] [Indexed: 01/22/2023]
Abstract
Environmental changes are expected to alter both the distribution and the abundance of organisms. A disproportionate amount of past work has focused on distribution only, either documenting historical range shifts or predicting future occurrence patterns. However, simultaneous predictions of abundance and distribution across landscapes would be far more useful. To critically assess which approaches represent advances towards the goal of joint predictions of abundance and distribution, we review recent work on changing distributions and on effects of environmental drivers on single populations. Several methods have been used to predict changing distributions. Some of these can be easily modified to also predict abundance, but others cannot. In parallel, demographers have developed a much better understanding of how changing abiotic and biotic drivers will influence growth rate and abundance in single populations. However, this demographic work has rarely taken a landscape perspective and has largely ignored the effects of intraspecific density. We advocate a synthetic approach in which population models accounting for both density dependence and effects of environmental drivers are used to make integrated predictions of equilibrium abundance and distribution across entire landscapes. Such predictions would constitute an important step forward in assessing the ecological consequences of environmental changes.
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Affiliation(s)
- Johan Ehrlén
- Department of Ecology, Environment and Plant Sciences, Stockholm UniversityStockholm, Sweden
| | - William F Morris
- Department of Ecology and Genetics, Uppsala UniversityUppsala, Sweden
- Department of Biology, Duke UniversityDurham, NC, USA
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44
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Molina-Zuluaga C, Restrepo A, Flechas SV, Daza JM. Short-Term Population Dynamics of Three Frog Species in the Northern Andes, Colombia. SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2014. [DOI: 10.2994/sajh-d-14-00009.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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45
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Lahoz-Monfort JJ, Harris MP, Morgan BJT, Freeman SN, Wanless S. Exploring the consequences of reducing survey effort for detecting individual and temporal variability in survival. J Appl Ecol 2014. [DOI: 10.1111/1365-2664.12214] [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)
- José J. Lahoz-Monfort
- National Centre for Statistical Ecology; School of Mathematics, Statistics & Actuarial Science; University of Kent; Canterbury Kent CT2 7NF UK
- Centre for Ecology & Hydrology; Maclean Building Crowmarsh Gifford Wallingford Oxfordshire OX10 8BB UK
- School of Botany; University of Melbourne; Parkville Vic. 3010 Australia
| | - Michael P. Harris
- Centre for Ecology & Hydrology; Bush Estate; Penicuik Midlothian EH26 0QB UK
| | - Byron J. T. Morgan
- National Centre for Statistical Ecology; School of Mathematics, Statistics & Actuarial Science; University of Kent; Canterbury Kent CT2 7NF UK
| | - Stephen N. Freeman
- Centre for Ecology & Hydrology; Maclean Building Crowmarsh Gifford Wallingford Oxfordshire OX10 8BB UK
| | - Sarah Wanless
- Centre for Ecology & Hydrology; Bush Estate; Penicuik Midlothian EH26 0QB UK
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