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Spatially varying density dependence drives a shifting mosaic of survival in a recovering apex predator (Canis lupus)

Understanding landscape patterns in mortality risk is crucial for promoting recovery of threatened and endangered species. Humans affect mortality risk in large carnivores such as wolves (Canis lupus), but spatiotemporally varying density dependence can significantly influence the landscape of survi...

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Autores principales: O'Neil, Shawn T., Bump, Joseph K., Beyer, Dean E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5696399/
https://www.ncbi.nlm.nih.gov/pubmed/29187986
http://dx.doi.org/10.1002/ece3.3463
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author O'Neil, Shawn T.
Bump, Joseph K.
Beyer, Dean E.
author_facet O'Neil, Shawn T.
Bump, Joseph K.
Beyer, Dean E.
author_sort O'Neil, Shawn T.
collection PubMed
description Understanding landscape patterns in mortality risk is crucial for promoting recovery of threatened and endangered species. Humans affect mortality risk in large carnivores such as wolves (Canis lupus), but spatiotemporally varying density dependence can significantly influence the landscape of survival. This potentially occurs when density varies spatially and risk is unevenly distributed. We quantified spatiotemporal sources of variation in survival rates of gray wolves (C. lupus) during a 21‐year period of population recovery in the Upper Peninsula of Michigan, USA. We focused on mapping risk across time using Cox Proportional Hazards (CPH) models with time‐dependent covariates, thus exploring a shifting mosaic of survival. Extended CPH models and time‐dependent covariates revealed influences of seasonality, density dependence and experience, as well as individual‐level factors and landscape predictors of risk. We used results to predict the shifting landscape of risk at the beginning, middle, and end of the wolf recovery time series. Survival rates varied spatially and declined over time. Long‐term change was density‐dependent, with landscape predictors such as agricultural land cover and edge densities contributing negatively to survival. Survival also varied seasonally and depended on individual experience, sex, and resident versus transient status. The shifting landscape of survival suggested that increasing density contributed to greater potential for human conflict and wolf mortality risk. Long‐term spatial variation in key population vital rates is largely unquantified in many threatened, endangered, and recovering species. Variation in risk may indicate potential for source‐sink population dynamics, especially where individuals preemptively occupy suitable territories, which forces new individuals into riskier habitat types as density increases. We encourage managers to explore relationships between adult survival and localized changes in population density. Density‐dependent risk maps can identify increasing conflict areas or potential habitat sinks which may persist due to high recruitment in adjacent habitats.
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spelling pubmed-56963992017-11-29 Spatially varying density dependence drives a shifting mosaic of survival in a recovering apex predator (Canis lupus) O'Neil, Shawn T. Bump, Joseph K. Beyer, Dean E. Ecol Evol Original Research Understanding landscape patterns in mortality risk is crucial for promoting recovery of threatened and endangered species. Humans affect mortality risk in large carnivores such as wolves (Canis lupus), but spatiotemporally varying density dependence can significantly influence the landscape of survival. This potentially occurs when density varies spatially and risk is unevenly distributed. We quantified spatiotemporal sources of variation in survival rates of gray wolves (C. lupus) during a 21‐year period of population recovery in the Upper Peninsula of Michigan, USA. We focused on mapping risk across time using Cox Proportional Hazards (CPH) models with time‐dependent covariates, thus exploring a shifting mosaic of survival. Extended CPH models and time‐dependent covariates revealed influences of seasonality, density dependence and experience, as well as individual‐level factors and landscape predictors of risk. We used results to predict the shifting landscape of risk at the beginning, middle, and end of the wolf recovery time series. Survival rates varied spatially and declined over time. Long‐term change was density‐dependent, with landscape predictors such as agricultural land cover and edge densities contributing negatively to survival. Survival also varied seasonally and depended on individual experience, sex, and resident versus transient status. The shifting landscape of survival suggested that increasing density contributed to greater potential for human conflict and wolf mortality risk. Long‐term spatial variation in key population vital rates is largely unquantified in many threatened, endangered, and recovering species. Variation in risk may indicate potential for source‐sink population dynamics, especially where individuals preemptively occupy suitable territories, which forces new individuals into riskier habitat types as density increases. We encourage managers to explore relationships between adult survival and localized changes in population density. Density‐dependent risk maps can identify increasing conflict areas or potential habitat sinks which may persist due to high recruitment in adjacent habitats. John Wiley and Sons Inc. 2017-10-28 /pmc/articles/PMC5696399/ /pubmed/29187986 http://dx.doi.org/10.1002/ece3.3463 Text en © 2017 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution (http://creativecommons.org/licenses/by/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Research
O'Neil, Shawn T.
Bump, Joseph K.
Beyer, Dean E.
Spatially varying density dependence drives a shifting mosaic of survival in a recovering apex predator (Canis lupus)
title Spatially varying density dependence drives a shifting mosaic of survival in a recovering apex predator (Canis lupus)
title_full Spatially varying density dependence drives a shifting mosaic of survival in a recovering apex predator (Canis lupus)
title_fullStr Spatially varying density dependence drives a shifting mosaic of survival in a recovering apex predator (Canis lupus)
title_full_unstemmed Spatially varying density dependence drives a shifting mosaic of survival in a recovering apex predator (Canis lupus)
title_short Spatially varying density dependence drives a shifting mosaic of survival in a recovering apex predator (Canis lupus)
title_sort spatially varying density dependence drives a shifting mosaic of survival in a recovering apex predator (canis lupus)
topic Original Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5696399/
https://www.ncbi.nlm.nih.gov/pubmed/29187986
http://dx.doi.org/10.1002/ece3.3463
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