1
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Webber QMR, Laforge MP, Bonar M, Vander Wal E. The adaptive value of density-dependent habitat specialization and social network centrality. Nat Commun 2024; 15:4423. [PMID: 38789438 PMCID: PMC11126670 DOI: 10.1038/s41467-024-48657-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Density dependence is a fundamental ecological process. In particular, animal habitat selection and social behavior often affect fitness in a density-dependent manner. The Ideal Free Distribution (IFD) and niche variation hypothesis (NVH) present distinct predictions associated with Optimal Foraging Theory about how the effect of habitat selection on fitness varies with population density. Using caribou (Rangifer tarandus) in Canada as a model system, we test competing hypotheses about how habitat specialization, social behavior, and annual reproductive success (co)vary across a population density gradient. Within a behavioral reaction norm framework, we estimate repeatability, behavioral plasticity, and covariance among social behavior and habitat selection to investigate the adaptive value of sociality and habitat selection. In support of NVH, but not the IFD, we find that at high density habitat specialists had higher annual reproductive success than generalists, but were also less social than generalists, suggesting the possibility that specialists were less social to avoid competition. Our study supports niche variation as a mechanism for density-dependent habitat specialization.
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Affiliation(s)
- Quinn M R Webber
- Cognitive and Behavioural Ecology Interdisciplinary Program, Memorial University of Newfoundland, St. John's, NF, Canada.
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada.
| | - Michel P Laforge
- Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | - Maegwin Bonar
- Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, USA
| | - Eric Vander Wal
- Cognitive and Behavioural Ecology Interdisciplinary Program, Memorial University of Newfoundland, St. John's, NF, Canada
- Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada
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2
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Hatton IA, Mazzarisi O, Altieri A, Smerlak M. Diversity begets stability: Sublinear growth and competitive coexistence across ecosystems. Science 2024; 383:eadg8488. [PMID: 38484074 DOI: 10.1126/science.adg8488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 02/07/2024] [Indexed: 03/19/2024]
Abstract
The worldwide loss of species diversity brings urgency to understanding how diverse ecosystems maintain stability. Whereas early ecological ideas and classic observations suggested that stability increases with diversity, ecological theory makes the opposite prediction, leading to the long-standing "diversity-stability debate." Here, we show that this puzzle can be resolved if growth scales as a sublinear power law with biomass (exponent <1), exhibiting a form of population self-regulation analogous to models of individual ontogeny. We show that competitive interactions among populations with sublinear growth do not lead to exclusion, as occurs with logistic growth, but instead promote stability at higher diversity. Our model realigns theory with classic observations and predicts large-scale macroecological patterns. However, it makes an unsettling prediction: Biodiversity loss may accelerate the destabilization of ecosystems.
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Affiliation(s)
- Ian A Hatton
- Max Planck Institute for Mathematics in the Sciences, 04103 Leipzig, Germany
- Department of Earth and Planetary Sciences, McGill University, Montreal, QC H3A 0E8, Canada
| | - Onofrio Mazzarisi
- Max Planck Institute for Mathematics in the Sciences, 04103 Leipzig, Germany
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045, USA
- The Abdus Salam International Centre for Theoretical Physics (ICTP), 34014 Trieste, Italy
- National Institute of Oceanography and Applied Geophysics (OGS), 34014 Trieste, Italy
| | - Ada Altieri
- Laboratoire Matière et Systèmes Complexes (MSC), Université Paris Cité CNRS, 75013 Paris, France
| | - Matteo Smerlak
- Max Planck Institute for Mathematics in the Sciences, 04103 Leipzig, Germany
- Laboratoire de Biophysique et Evolution, UMR 8231 CBI, ESPCI Paris, PSL Research University, 75005 Paris, France
- Capital Fund Management, 75007 Paris, France
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3
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Faull J, Conteddu K, Griffin LL, Amin B, Smith AF, Haigh A, Ciuti S. Do human-wildlife interactions predict offspring hiding strategies in peri-urban fallow deer? ROYAL SOCIETY OPEN SCIENCE 2024; 11:231470. [PMID: 38511083 PMCID: PMC10951722 DOI: 10.1098/rsos.231470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 02/08/2024] [Accepted: 02/16/2024] [Indexed: 03/22/2024]
Abstract
Human activities can induce significant behavioural changes in wildlife. Often explored through extractive interactions (e.g. hunting) that can favour certain behavioural traits, the implications of non-extractive ones, such as wildlife feeding, remain understudied. Research shows that people tend to favour bolder individuals within populations despite their dynamics and consequences being unclear. Using fallow deer in a peri-urban environment, we studied whether mothers that show reduced fear of humans and consistently approach them for food adopt weaker anti-predator strategies by selecting less concealed fawning bedsites closer to human hotspots. This would provide the advantage of additional feeding opportunities in comparison with shyer mothers while keeping their fawns close. Our dataset encompassed 281 capture events of 172 fawns from 110 mothers across 4 years. Surprisingly, mothers that regularly accepted food from humans selected more concealed bedsites farther from human hotspots, giving their offspring better protection while also benefitting from additional food during lactation. Our results show behavioural adaptations by a subset of females and, for the first time, link the tendency to approach humans and strategies to protect offspring. Given previous findings that these begging females also deliver heavier fawns at birth, our research further investigates human-wildlife feeding interactions and their behavioural implications.
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Affiliation(s)
- Jane Faull
- Laboratory of Wildlife Ecology and Behaviour, SBES, University College Dublin, Dublin4, Ireland
| | - Kimberly Conteddu
- Laboratory of Wildlife Ecology and Behaviour, SBES, University College Dublin, Dublin4, Ireland
| | - Laura L. Griffin
- Laboratory of Wildlife Ecology and Behaviour, SBES, University College Dublin, Dublin4, Ireland
- Department of Forest Resources Management, University of British Columbia, 2424 Main, Mall, VancouverV6T 1Z4, Canada
| | - Bawan Amin
- Laboratory of Wildlife Ecology and Behaviour, SBES, University College Dublin, Dublin4, Ireland
| | - Adam F. Smith
- The Frankfurt Zoological Society, Frankfurt, Germany
- Faculty of Environment and Natural Resources, Department of Wildlife Ecology and Management, University of Freiburg, Freiburg, Germany
| | - Amy Haigh
- Laboratory of Wildlife Ecology and Behaviour, SBES, University College Dublin, Dublin4, Ireland
| | - Simone Ciuti
- Laboratory of Wildlife Ecology and Behaviour, SBES, University College Dublin, Dublin4, Ireland
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4
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Hin V, de Roos AM, Benoit-Bird KJ, Claridge DE, DiMarzio N, Durban JW, Falcone EA, Jacobson EK, Jones-Todd CM, Pirotta E, Schorr GS, Thomas L, Watwood S, Harwood J. Using individual-based bioenergetic models to predict the aggregate effects of disturbance on populations: A case study with beaked whales and Navy sonar. PLoS One 2023; 18:e0290819. [PMID: 37651444 PMCID: PMC10470956 DOI: 10.1371/journal.pone.0290819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 08/16/2023] [Indexed: 09/02/2023] Open
Abstract
Anthropogenic activities can lead to changes in animal behavior. Predicting population consequences of these behavioral changes requires integrating short-term individual responses into models that forecast population dynamics across multiple generations. This is especially challenging for long-lived animals, because of the different time scales involved. Beaked whales are a group of deep-diving odontocete whales that respond behaviorally when exposed to military mid-frequency active sonar (MFAS), but the effect of these nonlethal responses on beaked whale populations is unknown. Population consequences of aggregate exposure to MFAS was assessed for two beaked whale populations that are regularly present on U.S. Navy training ranges where MFAS is frequently used. Our approach integrates a wide range of data sources, including telemetry data, information on spatial variation in habitat quality, passive acoustic data on the temporal pattern of sonar use and its relationship to beaked whale foraging activity, into an individual-based model with a dynamic bioenergetic module that governs individual life history. The predicted effect of disturbance from MFAS on population abundance ranged between population extinction to a slight increase in population abundance. These effects were driven by the interaction between the temporal pattern of MFAS use, baseline movement patterns, the spatial distribution of prey, the nature of beaked whale behavioral response to MFAS and the top-down impact of whale foraging on prey abundance. Based on these findings, we provide recommendations for monitoring of marine mammal populations and highlight key uncertainties to help guide future directions for assessing population impacts of nonlethal disturbance for these and other long-lived animals.
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Affiliation(s)
- Vincent Hin
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- Wageningen Marine Research, IJmuiden, The Netherlands
| | - André M. de Roos
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- Santa Fe Institute, Santa Fe, New Mexico, United States of America
| | - Kelly J. Benoit-Bird
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | | | - Nancy DiMarzio
- Naval Undersea Warfare Center, Newport, Rhode Island, United States of America
| | | | - Erin A. Falcone
- Marine Ecology and Telemetry Research, Seabeck, Washington, United States of America
| | - Eiren K. Jacobson
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, United Kingdom
| | | | - Enrico Pirotta
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, United Kingdom
| | - Gregory S. Schorr
- Marine Ecology and Telemetry Research, Seabeck, Washington, United States of America
| | - Len Thomas
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, United Kingdom
| | - Stephanie Watwood
- Naval Undersea Warfare Center, Newport, Rhode Island, United States of America
| | - John Harwood
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, United Kingdom
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5
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Brushett A, Whittington J, Macbeth B, Fryxell JM. Changes in movement, habitat use, and response to human disturbance accompany parturition events in bighorn sheep (Ovis canadensis). MOVEMENT ECOLOGY 2023; 11:36. [PMID: 37403172 DOI: 10.1186/s40462-023-00404-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/27/2023] [Indexed: 07/06/2023]
Abstract
Parturition and the early neonatal period are critical life history stages in ungulates with considerable implications for population growth and persistence. Understanding the changes in behaviour induced by ungulate parturition is important for supporting effective population management, but reliably identifying birth sites and dates presents a challenge for managers. Rocky Mountain bighorn sheep (Ovis canadensis canadensis) are one such highly valued and ecologically important species in montane and subalpine ecosystems of Western North America. In the face of changing patterns of anthropogenic land use, wildlife managers increasingly require site-specific knowledge of the movement and habitat selection characteristics of periparturient sheep to better inform land use planning initiatives and ensure adequate protections for lambing habitat. We used movement data from GPS collared parturient (n = 13) and non-parturient (n = 8) bighorn sheep in Banff National Park, Canada to (1) identify lambing events based on changes in key movement metrics, and (2) investigate how resource selection and responses to human use change during the periparturient period. We fit a hidden Markov model (HMM) to a multivariate characterization of sheep movement (step length, daily home range area, residence time) to predict realistic lambing dates for the animals in our study system. Leave-one-out cross validation of our model resulted in a 93% success rate for parturient females. Our model, which we parameterized using data from known parturient females, also predicted lambing events in 25% of known non-parturient ewes in a test dataset. Using a latent selection difference function and resource selection functions, we tested for postpartum changes in habitat use, as well as seasonal differences in habitat selection. Immediately following lambing, ewes preferentially selected high-elevation sites on solar aspects that were more rugged, closer to escape terrain, and further from roads. Within-home range habitat selection was similar between individuals in different reproductive states, but parturient ewes had stronger selection for low snow depth, sites closer to barren ground, and sites further from trails. We propose that movement-based approaches such as HMMs are a valuable tool for identifying critical parturition habitat in species with complex movement patterns and may have particular utility in study areas without access to extensive field observations or vaginal implant transmitters. Furthermore, our results suggest that managers should minimize human disturbance in lambing areas to avoid interfering with maternal behaviour and ensure access to a broad range of suitable habitat in the periparturient period.
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Affiliation(s)
- Aidan Brushett
- Parks Canada, Banff National Park Resource Conservation, PO Box 900, Banff, AB, T1L 1K2, Canada.
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
| | - Jesse Whittington
- Parks Canada, Banff National Park Resource Conservation, PO Box 900, Banff, AB, T1L 1K2, Canada
| | - Bryan Macbeth
- Parks Canada, Banff National Park Resource Conservation, PO Box 900, Banff, AB, T1L 1K2, Canada
| | - John M Fryxell
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
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6
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Conquet E, Ozgul A, Blumstein DT, Armitage KB, Oli MK, Martin JGA, Clutton-Brock TH, Paniw M. Demographic consequences of changes in environmental periodicity. Ecology 2023; 104:e3894. [PMID: 36208282 DOI: 10.1002/ecy.3894] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 07/27/2022] [Accepted: 08/04/2022] [Indexed: 01/24/2023]
Abstract
The fate of natural populations is mediated by complex interactions among vital rates, which can vary within and among years. Although the effects of random, among-year variation in vital rates have been studied extensively, relatively little is known about how periodic, nonrandom variation in vital rates affects populations. This knowledge gap is potentially alarming as global environmental change is projected to alter common periodic variations, such as seasonality. We investigated the effects of changes in vital-rate periodicity on populations of three species representing different forms of adaptation to periodic environments: the yellow-bellied marmot (Marmota flaviventer), adapted to strong seasonality in snowfall; the meerkat (Suricata suricatta), adapted to inter-annual stochasticity as well as seasonal patterns in rainfall; and the dewy pine (Drosophyllum lusitanicum), adapted to fire regimes and periodic post-fire habitat succession. To assess how changes in periodicity affect population growth, we parameterized periodic matrix population models and projected population dynamics under different scenarios of perturbations in the strength of vital-rate periodicity. We assessed the effects of such perturbations on various metrics describing population dynamics, including the stochastic growth rate, log λS . Overall, perturbing the strength of periodicity had strong effects on population dynamics in all three study species. For the marmots, log λS decreased with increased seasonal differences in adult survival. For the meerkats, density dependence buffered the effects of perturbations of periodicity on log λS . Finally, dewy pines were negatively affected by changes in natural post-fire succession under stochastic or periodic fire regimes with fires occurring every 30 years, but were buffered by density dependence from such changes under presumed more frequent fires or large-scale disturbances. We show that changes in the strength of vital-rate periodicity can have diverse but strong effects on population dynamics across different life histories. Populations buffered from inter-annual vital-rate variation can be affected substantially by changes in environmentally driven vital-rate periodic patterns; however, the effects of such changes can be masked in analyses focusing on inter-annual variation. As most ecosystems are affected by periodic variations in the environment such as seasonality, assessing their contributions to population viability for future global-change research is crucial.
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Affiliation(s)
- Eva Conquet
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Daniel T Blumstein
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, California, USA.,The Rocky Mountain Biological Laboratory, Crested Butte, Colorado, USA
| | - Kenneth B Armitage
- Department of Ecology and Evolutionary Biology, The University of Kansas, Lawrence, Kansas, USA
| | - Madan K Oli
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, USA
| | - Julien G A Martin
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.,School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Tim H Clutton-Brock
- Department of Zoology, University of Cambridge, Cambridge, UK.,Kalahari Research Trust, Kuruman River Reserve, Northern Cape, South Africa.,Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Maria Paniw
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Department of Conservation and Global Change, Doñana Biological Station (EBD-CSIC), Seville, Spain
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7
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Bergeron R, Pigeon G, Forsyth DM, King WJ, Festa-Bianchet M. Post-weaning survival in kangaroos is high and constant until senescence: Implications for population dynamics. Ecology 2023; 104:e3963. [PMID: 36545886 DOI: 10.1002/ecy.3963] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 10/28/2022] [Accepted: 11/22/2022] [Indexed: 12/24/2022]
Abstract
Large herbivores typically have consistently high prime-aged adult survival and lower, more variable, juvenile, and senescent survival. Many kangaroo populations undergo greater fluctuations in density compared with other large herbivores, but age- and sex-specific survival of kangaroos and their response to environmental variation remain poorly estimated. We used long-term capture-mark-recapture data on 920 individuals to investigate the survival component of eastern grey kangaroo (Macropus giganteus) population dynamics. Forage availability and population density were monitored quarterly and included as predictors of survival in Bayesian Cormack-Jolly-Seber models. Annual survival probabilities were estimated for five age classes: 0 years (juveniles), 1-2 years (subadults), 3-6 years (prime-aged adults), 7-9 years (presenescent adults), and ≥10 years (senescent adults). Survival of juveniles varied widely during our 12-year study, ranging from 0.07 to 0.90 for females and 0.05-0.92 for males. Subadult survival was 0.80-0.93 for females and 0.75-0.85 for males, while that of prime-aged adults was ≥0.94 for females and ≥0.83 for males, despite large fluctuations in forage and density. The survival of presenescent adults spanned 0.86-0.93 for females and 0.60-0.86 for males. Senescent survival was variable, at 0.49-0.90 for females and 0.49-0.80 for males. Male survival was significantly lower than female survival in prime-aged and presenescent adults, but not in other age classes. Although most of the models supported by Watanabe-Akaike Information Criterion selection included at least one environmental covariate, none of these covariates individually had a discernible effect on survival. Temporal variability in overall survival appeared mostly due to changes in the survival of juvenile and senescent kangaroos. Kangaroo survival patterns are similar to those of ungulates, suggesting a strong role of sex-age structure on population dynamics.
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Affiliation(s)
- Rachel Bergeron
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Gabriel Pigeon
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, Québec, Canada
| | - David M Forsyth
- New South Wales Department of Primary Industries, Orange, New South Wales, Australia
| | - Wendy J King
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Marco Festa-Bianchet
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada.,Research School of Biology, The Australian National University, Acton, Australian Capital Territory, Australia
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8
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Abstract
Large brains provide adaptive cognitive benefits but require unusually high, near-constant energy inputs and become fully functional well after their growth is completed. Consequently, young of most larger-brained endotherms should not be able to independently support the growth and development of their own brains. This paradox is solved if the evolution of extended parental provisioning facilitated brain size evolution. Comparative studies indeed show that extended parental provisioning coevolved with brain size and that it may improve immature survival. The major role of extended parental provisioning supports the idea that the ability to sustain the costs of brains limited brain size evolution.
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9
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Milleret C, Dey S, Dupont P, Brøseth H, Turek D, de Valpine P, Bischof R. Estimating spatially variable and density-dependent survival using open-population spatial capture-recapture models. Ecology 2023; 104:e3934. [PMID: 36458376 PMCID: PMC10078101 DOI: 10.1002/ecy.3934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 10/07/2022] [Indexed: 12/05/2022]
Abstract
Open-population spatial capture-recapture (OPSCR) models use the spatial information contained in individual detections collected over multiple consecutive occasions to estimate not only occasion-specific density, but also demographic parameters. OPSCR models can also estimate spatial variation in vital rates, but such models are neither widely used nor thoroughly tested. We developed a Bayesian OPSCR model that not only accounts for spatial variation in survival using spatial covariates but also estimates local density-dependent effects on survival within a unified framework. Using simulations, we show that OPSCR models provide sound inferences on the effect of spatial covariates on survival, including multiple competing sources of mortality, each with potentially different spatial determinants. Estimation of local density-dependent survival was possible but required more data due to the greater complexity of the model. Not accounting for spatial heterogeneity in survival led to up to 10% positive bias in abundance estimates. We provide an empirical demonstration of the model by estimating the effect of country and density on cause-specific mortality of female wolverines (Gulo gulo) in central Sweden and Norway. The ability to make population-level inferences on spatial variation in survival is an essential step toward a fully spatially explicit OPSCR model capable of disentangling the role of multiple spatial drivers of population dynamics.
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Affiliation(s)
- Cyril Milleret
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Soumen Dey
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Pierre Dupont
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Henrik Brøseth
- Norwegian Institute for Nature Research (NINA), Trondheim, Norway
| | - Daniel Turek
- Department of Mathematics and Statistics, Williams College, Williamstown, Massachusetts, USA
| | - Perry de Valpine
- Department of Environmental Science, Policy and Management, University of California Berkeley, Berkeley, California, USA
| | - Richard Bischof
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
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10
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Bonenfant C, Rutschmann A, Burton J, Boyles R, García F, Tilker A, Schütz E. Cast away on Mindoro island: lack of space limits population growth of the endangered tamaraw. Anim Conserv 2023. [DOI: 10.1111/acv.12842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- C. Bonenfant
- UMR CNRS 5558, Laboratoire “Biométrie et Biologie Évolutive”, Université Lyon 1 Villeurbanne France
| | - A. Rutschmann
- School of Biological Sciences University of Auckland Auckland New Zealand
| | - J. Burton
- IUCN SSC Asian Wild Cattle Specialist Group Chester Zoo Chester UK
- Re:wild Austin TX USA
| | - R. Boyles
- Department of Environment and Natural Resources of the Philippines Barangay Payompon Occidental Mindoro Philippines
| | - F. García
- D'Aboville Foundation and Demo Farm, Inc. Manila Philippines
| | - A. Tilker
- Re:wild Austin TX USA
- Leibniz Institute for Zoo and Wildlife Research Berlin Germany
| | - E. Schütz
- D'Aboville Foundation and Demo Farm, Inc. Manila Philippines
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11
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Bluhm H, Diserens TA, Engleder T, Heising K, Heurich M, Janík T, Jirků M, Klich D, König HJ, Kowalczyk R, Kuijper D, Maślanko W, Michler F, Neumann W, Oeser J, Olech W, Perzanowski K, Ratkiewicz M, Romportl D, Šálek M, Kuemmerle T. Widespread habitat for Europe's largest herbivores, but poor connectivity limits recolonization. DIVERS DISTRIB 2023. [DOI: 10.1111/ddi.13671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Hendrik Bluhm
- Geography Department Humboldt‐Universität zu Berlin Berlin Germany
| | - Tom A. Diserens
- Mammal Research Institute Polish Academy of Sciences Białowieża Poland
- Faculty of Biology University of Warsaw Warsaw Poland
| | | | - Kaja Heising
- Wisent‐Welt Wittgenstein e.V Bad Berleburg Germany
| | - Marco Heurich
- Chair of Wildlife Ecology and Wildlife Management University of Freiburg Freiburg Germany
- Department of Visitor Management and National Park Monitoring Bavarian Forest National Park Grafenau Germany
- Institute for Forest and Wildlife Management Inland Norway University of Applied Sciences Koppang Norway
| | - Tomáš Janík
- Department of Physical Geography and Geoecology, Faculty of Science Charles University Praha Czechia
- Department of Spatial Ecology The Silva Tarouca Research Institute for Landscape and Ornamental Gardening (VÚKOZ) Průhonice Czechia
| | - Miloslav Jirků
- Institute of Parasitology, Biology Centre Czech Academy of Sciences České Budějovice Czech Republic
| | - Daniel Klich
- Department of Animal Genetics and Conservation Warsaw University of Life Sciences Warsaw Poland
| | - Hannes J. König
- Junior Research Group Human‐Wildlife Conflict and Coexistence Leibniz Centre for Agricultural Landscape Research (ZALF) Müncheberg Germany
| | - Rafał Kowalczyk
- Mammal Research Institute Polish Academy of Sciences Białowieża Poland
| | - Dries Kuijper
- Mammal Research Institute Polish Academy of Sciences Białowieża Poland
| | - Weronika Maślanko
- Department of Animal Ethology and Wildlife Management University of Life Sciences in Lublin Lublin Poland
| | - Frank‐Uwe Michler
- Faculty of Forest and Environment Eberswalde University for Sustainable Development Eberswalde Germany
| | - Wiebke Neumann
- Department of Wildlife, Fish and Environmental Studies Swedish University of Agricultural Sciences
| | - Julian Oeser
- Geography Department Humboldt‐Universität zu Berlin Berlin Germany
| | - Wanda Olech
- Department of Animal Genetics and Conservation Warsaw University of Life Sciences Warsaw Poland
| | - Kajetan Perzanowski
- Institute of Biological Sciences Catholic University of Lublin Lublin Poland
| | | | - Dušan Romportl
- Department of Physical Geography and Geoecology, Faculty of Science Charles University Praha Czechia
- Department of Spatial Ecology The Silva Tarouca Research Institute for Landscape and Ornamental Gardening (VÚKOZ) Průhonice Czechia
| | - Martin Šálek
- Czech Academy of Sciences Institute of Vertebrate Biology Brno Czech Republic
- Faculty of Environmental Sciences Czech University of Life Sciences Prague Suchdol Czech Republic
| | - Tobias Kuemmerle
- Geography Department Humboldt‐Universität zu Berlin Berlin Germany
- Integrative Research Institute on Transformation in Human‐Environment Systems (IRI THESys) Humboldt‐Universität zu Berlin Berlin Germany
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12
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Aguirrebengoa M, Müller C, Hambäck PA, González-Megías A. Density-Dependent Effects of Simultaneous Root and Floral Herbivory on Plant Fitness and Defense. PLANTS (BASEL, SWITZERLAND) 2023; 12:283. [PMID: 36678999 PMCID: PMC9867048 DOI: 10.3390/plants12020283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/23/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
Plants are attacked by multiple herbivores, and depend on a precise regulation of responses to cope with a wide range of antagonists. Simultaneous herbivory can occur in different plant compartments, which may pose a serious threat to plant growth and reproduction. In particular, plants often face co-occurring root and floral herbivory, but few studies have focused on such interactions. Here, we investigated in the field the combined density-dependent effects of root-chewing cebrionid beetle larvae and flower-chewing pierid caterpillars on the fitness and defense of a semiarid Brassicaceae herb. We found that the fitness impact of both herbivore groups was independent and density-dependent. Increasing root herbivore density non-significantly reduced plant fitness, while the relationship between increasing floral herbivore density and the reduction they caused in both seed number and seedling emergence was non-linear. The plant defensive response was non-additive with regard to the different densities of root and floral herbivores; high floral herbivore density provoked compensatory investment in reproduction, and this tolerance response was combined with aboveground chemical defense induction when also root herbivore density was high. Plants may thus prioritize specific trait combinations in response to varying combined below- and aboveground herbivore densities to minimize negative impacts on fitness.
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Affiliation(s)
| | - Caroline Müller
- Department of Chemical Ecology, Bielefeld University, 33615 Bielefeld, Germany
| | - Peter A. Hambäck
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden
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13
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Mysterud A, Langvatn R, Meisingset EL, Rivrud IM. Agricultural grasslands buffer density effects in red deer populations. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Atle Mysterud
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences University of Oslo P.O. Box 1066 Blindern NO‐0316 Oslo Norway
| | | | - Erling L. Meisingset
- Department of Forestry and Forestry Resources Norwegian Institute of Bioeconomy Research Tingvoll gard NO‐6630 Tingvoll Norway
| | - Inger Maren Rivrud
- Norwegian Institute for Nature Research (NINA) Sognsveien 68 NO‐0855 Oslo Norway
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14
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McFarlane S, Manseau M, Jones TB, Pouliot D, Mastromonaco G, Pittoello G, Wilson PJ. Identification of familial networks reveals sex-specific density dependence in the dispersal and reproductive success of an endangered ungulate. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.956834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Density is an important demographic parameter that is commonly overlooked in studies of wild populations. Here, we examined the effects of variable spatially explicit density on a range of demographic parameters in a wild population of a cryptic ungulate, boreal woodland caribou (Rangifer tarandus caribou). Using non-invasive genetic sampling, we applied spatial capture–recapture methods with landscape covariates to estimate the density of boreal woodland caribou across a 108,806 km2 study area. We then created a familial network from the reconstructed parent–offspring relationships to determine whether spatial density influenced sex-specific individual reproductive success, female pregnancy status, and dispersal distance. We found that animal density varied greatly in response to land cover types and disturbance; animal density was most influenced by landscape composition and distance to roads varying from 0 in areas with >20% deciduous cover to 270 caribou per 1,000 km2 in areas presenting contiguous older coniferous cover. We found that both male and female reproductive success varied with density, with males showing a higher probability of having offspring in higher-density areas, and the opposite for females. No differences were found in female pregnancy rates occurring in high- and low-density areas. Dispersal distances varied with density, with offspring moving shorter distances when parents were found in higher-density areas. Familial networks showed lower-closeness centrality and lower-degree centrality for females in higher-density areas, indicating that females found in higher-density areas tend to be less broadly associated with animals across the range. Although high-density areas do reflect good-quality caribou habitat, the observed decreased closeness and degree centrality measures, dispersal rates, and lower female recruitment rates suggest that remnant habitat patches across the landscape may create population sinks.
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15
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F. Millán M, Carranza J, Seoane JM, Pérez-González J. Forage quality of consecutive years interact to affect body condition, reproductive rate and rut phenology in Iberian red deer. PLoS One 2022; 17:e0278367. [PMID: 36454913 PMCID: PMC9714875 DOI: 10.1371/journal.pone.0278367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 11/15/2022] [Indexed: 12/03/2022] Open
Abstract
Body condition for reproduction in capital breeders such as the red deer (Cervus elaphus) is mostly determined by their stored energy reserves. Thus, environmental conditions and resource availability may affect reproductive performance and breeding success. In warm Mediterranean regions, current climate change is driving to a hotter and drier scenario that is expected to affect the biology and dynamics of many populations. We examined the impact of these local climate variations on red deer body condition and the relationship with female reproductive phenology and breeding success. We used satellite information of landscape vegetation along with a 22-year data series of direct field behavioural observations during the rutting season in Doñana National Park (SW Spain). We analyzed faecal nitrogen content (FN) from faeces collected during the rut. We found that poor vegetation availability in drier years was related to worse body condition of deer (measured by FN) and a delay in the rutting season, which associated with lower reproductive rates (measured by the proportion of females with calves observed the next year). We also evidenced an interesting interaction between environmental conditions in consecutive years on the timing of breeding season, with timing of breeding being more delayed when previous year resource availability was high and many females bred, and the consecutive one was poor, so females hardly recovered condition and the rut occurred later. These findings highlight the carry-over effect of reproduction in capital breeders and the potential impact of climate-change conditions on red deer breeding.
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Affiliation(s)
- Marina F. Millán
- Wildlife Research Unit (UIRCP), Universidad de Córdoba, Córdoba, Spain
- * E-mail: (MFM); (JC)
| | - Juan Carranza
- Wildlife Research Unit (UIRCP), Universidad de Córdoba, Córdoba, Spain
- * E-mail: (MFM); (JC)
| | - José M. Seoane
- Wildlife Research Unit (UIRCP), Universidad de Córdoba, Córdoba, Spain
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16
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Flesch AD. Landcover change and habitat quality mediate impacts of temperature and precipitation on population dynamics of a threatened aridland predator. Anim Conserv 2022. [DOI: 10.1111/acv.12836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- A. D. Flesch
- School of Natural Resources and the Environment University of Arizona Tucson AZ USA
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17
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Monson DH, Taylor RL, Hilderbrand GV, Erlenbach JA, Coletti HA, Kloecker KA, Esslinger GG, Bodkin JL. Brown bear–sea otter interactions along the Katmai coast: terrestrial and nearshore communities linked by predation. J Mammal 2022. [DOI: 10.1093/jmammal/gyac095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Sea otters were extirpated throughout much of their range by the maritime fur trade in the 18th and 19th centuries, including the coast of Katmai National Park and Preserve in southcentral Alaska. Brown bears are an important component of the Katmai ecosystem where they are the focus of a thriving ecotourism bear-viewing industry as they forage in sedge meadows and dig clams in the extensive tidal flats that exist there. Sea otters began reoccupying Katmai in the 1970s where their use of intertidal clam resources overlapped that of brown bears. By 2008, the Katmai sea otter population had grown to an estimated 7,000 animals and was likely near carrying capacity; however, in 2006–2015, the age-at-death distribution (AADD) of sea otter carcasses collected at Katmai included a higher-than-expected proportion of prime-age animals compared to most other sea otter populations in Alaska. The unusual AADD warranted scientific investigation, particularly because the Katmai population is part of the Threatened southwest sea otter stock. Brown bears in Katmai are known to prey on marine mammals and sea otters, but depredation rates are unknown; thus, we investigated carnivore predation, especially by brown bears, as a potential explanation for abnormally high prime-age otter mortality. We installed camera traps at two island-based marine mammal haulout sites within Katmai to gather direct evidence that brown bears prey on seals and sea otters. Over a period of two summers, we gathered photo evidence of brown bears making 22 attempts to prey on sea otters of which nine (41%) were successful and 12 attempts to prey on harbor seals of which one (8%) was successful. We also developed a population model based on the AADD to determine if the living population is declining, as suggested by the high proportion of prime-age animals in the AADD. We found that the population trend predicted by the modeled AADDs was contradictory to aerial population surveys that indicated the population was not in steep decline but was consistent with otter predation. Future work should focus on the direct and indirect effects these top-level predators have on each other and the coastal community that connects them.
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Affiliation(s)
- Daniel H Monson
- U.S. Geological Survey, Alaska Science Center , 4210 University Avenue, Anchorage, Alaska 99508 , USA
| | - Rebecca L Taylor
- U.S. Geological Survey, Alaska Science Center , 4210 University Avenue, Anchorage, Alaska 99508 , USA
| | - Grant V Hilderbrand
- National Park Service, Alaska Regional Office , 240 W. 5th Avenue, Anchorage, Alaska 99501 , USA
| | - Joy A Erlenbach
- School of Biological Sciences, Washington State University , Pullman, Washington 99164 , USA
| | - Heather A Coletti
- National Park Service, Southwest Alaska Inventory and Monitoring Program , 4175 Geist Road, Fairbanks, Alaska 99709 , USA
| | - Kimberly A Kloecker
- U.S. Geological Survey, Alaska Science Center , 4210 University Avenue, Anchorage, Alaska 99508 , USA
| | - George G Esslinger
- U.S. Geological Survey, Alaska Science Center , 4210 University Avenue, Anchorage, Alaska 99508 , USA
| | - James L Bodkin
- U.S. Geological Survey, Alaska Science Center , 4210 University Avenue, Anchorage, Alaska 99508 , USA
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Riecke TV, Lohman MG, Sedinger BS, Arnold TW, Feldheim CL, Koons DN, Rohwer FC, Schaub M, Williams PJ, Sedinger JS. Density-dependence produces spurious relationships among demographic parameters in a harvested species. J Anim Ecol 2022; 91:2261-2272. [PMID: 36054772 PMCID: PMC9826280 DOI: 10.1111/1365-2656.13807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 08/10/2022] [Indexed: 01/11/2023]
Abstract
Harvest of wild organisms is an important component of human culture, economy, and recreation, but can also put species at risk of extinction. Decisions that guide successful management actions therefore rely on the ability of researchers to link changes in demographic processes to the anthropogenic actions or environmental changes that underlie variation in demographic parameters. Ecologists often use population models or maximum sustained yield curves to estimate the impacts of harvest on wildlife and fish populations. Applications of these models usually focus exclusively on the impact of harvest and often fail to consider adequately other potential, often collinear, mechanistic drivers of the observed relationships between harvest and demographic rates. In this study, we used an integrated population model and long-term data (1973-2016) to examine the relationships among hunting and natural mortality, the number of hunters, habitat conditions, and population size of blue-winged teal Spatula discors, an abundant North American dabbling duck with a relatively fast-paced life history strategy. Over the last two and a half decades of the study, teal abundance tripled, hunting mortality probability increased slightly ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics><mml:mrow><mml:mo><</mml:mo> <mml:mn>0.02</mml:mn></mml:mrow> </mml:semantics> </mml:math> ), and natural mortality probability increased substantially ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics><mml:mrow><mml:mo>></mml:mo> <mml:mn>0.1</mml:mn></mml:mrow> </mml:semantics> </mml:math> ) at greater population densities. We demonstrate strong density-dependent effects on natural mortality and fecundity as population density increased, indicative of compensatory harvest mortality and compensatory natality. Critically, an analysis that only assessed the relationship between survival and hunting mortality would spuriously indicate depensatory mortality due to multicollinearity between abundance, natural mortality and hunting mortality. Our findings demonstrate that models that only consider the direct effect of hunting on survival or natural mortality can fail to accurately assess the mechanistic impact of hunting on population dynamics due to multicollinearity among demographic drivers. This multicollinearity limits inference and may have strong impacts on applied management actions globally.
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Affiliation(s)
- Thomas V. Riecke
- Graduate Program in Ecology, Evolution, and Conservation BiologyUniversity of NevadaRenoNevadaUSA,Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA,Swiss Ornithological InstituteSempachSwitzerland
| | - Madeleine G. Lohman
- Graduate Program in Ecology, Evolution, and Conservation BiologyUniversity of NevadaRenoNevadaUSA,Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA
| | - Benjamin S. Sedinger
- Graduate Program in Ecology, Evolution, and Conservation BiologyUniversity of NevadaRenoNevadaUSA,Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA,University of Wisconsin–Stevens Point, Stevens PointStevens PointWisconsinUSA
| | - Todd W. Arnold
- Department of Fisheries, Wildlife, and Conservation BiologyUniversity of MinnesotaSt. PaulMinnesotaUSA
| | | | - David N. Koons
- Fish, Wildlife, and Conservation Biology & Graduate Degree Program in EcologyColorado State UniversityFt. CollinsColoradoUSA
| | | | | | - Perry J. Williams
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA
| | - James S. Sedinger
- Department of Natural Resources and Environmental ScienceUniversity of NevadaRenoNevadaUSA
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19
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Júnior ECB, Rios VP, Dodonov P, Vilela B, Japyassú HF. Effect of behavioural plasticity and environmental properties on the resilience of communities under habitat loss and fragmentation. Ecol Modell 2022. [DOI: 10.1016/j.ecolmodel.2022.110071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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20
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Johnson HE, Lenart EA, Gustine DD, Adams LG, Barboza PS. Survival and reproduction in Arctic caribou are associated with summer forage and insect harassment. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.899585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Investigators have speculated that the climate-driven “greening of the Arctic” may benefit barren-ground caribou populations, but paradoxically many populations have declined in recent years. This pattern has raised concerns about the influence of summer habitat conditions on caribou demographic rates, and how populations may be impacted in the future. The short Arctic summer provides caribou with important forage resources but is also the time they are exposed to intense harassment by insects, factors which are both being altered by longer, warmer growing seasons. To better understand the effects of summer forage and insect activity on Arctic caribou demographic rates, we investigated the influence of estimated forage biomass, digestible energy (DE), digestible nitrogen (DN), and mosquito activity on the reproductive success and survival of adult females in the Central Arctic Herd on the North Slope of Alaska. We tested the hypotheses that greater early summer DN would increase subsequent reproduction (parturition and late June calving success) while greater biomass and DE would increase adult survival (September–May), and that elevated mosquito activity would reduce both demographic rates. Because the period when abundant forage DN is limited and overlaps with the period of mosquito harassment, we also expected years with low DN and high harassment to synergistically reduce caribou reproductive success. Examining these relationships at the individual-level, using GPS-collared females, and at the population-level, using long-term monitoring data, we generally found support for our expectations. Greater early summer DN was associated with increased subsequent calving success, while greater summer biomass was associated with increased adult survival. Mosquito activity was associated with reductions in adult female parturition, late June calving success, and survival, and in years with low DN, had compounding effects on subsequent late June calving success. Our findings indicate that summer nutrition and mosquito activity collectively influence the demographic rates of Arctic caribou, and may impact the dynamics of populations in the future under changing environmental conditions.
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21
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Mundinger C, Fleischer T, Scheuerlein A, Kerth G. Global warming leads to larger bats with a faster life history pace in the long-lived Bechstein's bat (Myotis bechsteinii). Commun Biol 2022; 5:682. [PMID: 35810175 PMCID: PMC9271042 DOI: 10.1038/s42003-022-03611-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 06/21/2022] [Indexed: 01/22/2023] Open
Abstract
Whether species can cope with environmental change depends considerably on their life history. Bats have long lifespans and low reproductive rates which make them vulnerable to environmental changes. Global warming causes Bechstein’s bats (Myotis bechsteinii) to produce larger females that face a higher mortality risk. Here, we test whether these larger females are able to offset their elevated mortality risk by adopting a faster life history. We analysed an individual-based 25-year dataset from 331 RFID-tagged wild bats and combine genetic pedigrees with data on survival, reproduction and body size. We find that size-dependent fecundity and age at first reproduction drive the observed increase in mortality. Because larger females have an earlier onset of reproduction and shorter generation times, lifetime reproductive success remains remarkably stable across individuals with different body sizes. Our study demonstrates a rapid shift to a faster pace of life in a mammal with a slow life history. Warming summers across a 25-year study are linked to larger body sizes in female bats, leading to a switch from a slow-reproducing, long-lived species to a faster pace of life.
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Affiliation(s)
- Carolin Mundinger
- Applied Zoology and Nature Conservation, Zoological Institute and Museum, University of Greifswald, Loitzer Straße 26, 17489, Greifswald, Germany.
| | - Toni Fleischer
- Leipzig University Medical Center, Department of Psychiatry and Psychotherapy, Semmelweisstraße 10, 04103, Leipzig, Germany
| | - Alexander Scheuerlein
- Applied Zoology and Nature Conservation, Zoological Institute and Museum, University of Greifswald, Loitzer Straße 26, 17489, Greifswald, Germany
| | - Gerald Kerth
- Applied Zoology and Nature Conservation, Zoological Institute and Museum, University of Greifswald, Loitzer Straße 26, 17489, Greifswald, Germany
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22
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Candolin U, Goncalves S, Pant P. Delayed early life effects in the threespine stickleback. Proc Biol Sci 2022; 289:20220554. [PMID: 35642365 PMCID: PMC9156908 DOI: 10.1098/rspb.2022.0554] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Early life conditions can have a decisive influence on viability later in life. However, the influence of embryo density within a nest or body cavity on subsequent viability has received little attention within an ecological setting. This is surprising given that embryos often compete for limited resources, such as nutrients and oxygen, and this could influence their viability later in life through carry-over and compensatory effects. We show that the density of fertilized eggs within the nests of threespine stickleback males (Gasterosteus aculeatus) influences their viability after hatching. Embryos from larger broods hatch earlier and at a smaller size than those from smaller broods, which reduces their survival until the age of four weeks. This indicates a trade-off between the number and viability of offspring that males can raise to the hatching stage, which could explain the high incidence of partial egg cannibalism in nest-brooding fishes-as a strategy to improve the survival of remaining offspring. These results highlight the importance of considering conditions at the embryonic stage when evaluating the impact of early life conditions on viability and the adaptive value of reproductive decisions.
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Affiliation(s)
- Ulrika Candolin
- Organismal and Evolutionary Biology, University of Helsinki, PO Box 65, FI-00014 Helsinki, Finland
| | - Sara Goncalves
- Organismal and Evolutionary Biology, University of Helsinki, PO Box 65, FI-00014 Helsinki, Finland
| | - Pankaj Pant
- Organismal and Evolutionary Biology, University of Helsinki, PO Box 65, FI-00014 Helsinki, Finland
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23
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Sauers LA, Hawes KE, Juliano SA. Non-linear relationships between density and demographic traits in three Aedes species. Sci Rep 2022; 12:8075. [PMID: 35577868 PMCID: PMC9110365 DOI: 10.1038/s41598-022-11909-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 04/29/2022] [Indexed: 11/15/2022] Open
Abstract
Understanding the relationship of population dynamics to density is central to many ecological investigations. Despite the importance of density-dependence in determining population growth, the empirical relationship between density and per capita growth remains understudied in most systems and is often assumed to be linear. In experimental studies of interspecific competition, investigators often evaluate the predicted outcomes by assuming such linear relationships, fitting linear functions, and estimating parameters of competition models. In this paper, we experimentally describe the shape of the relationship between estimated population rate of change and initial density using laboratory-reared populations of three mosquito species. We estimated per capita growth rate for these experimental populations over a 30-fold range of larval densities at a standard resource abundance. We then compared fits of linear models and several different nonlinear models for the relationship of estimated rate of change and density. We find that that the relationship between density and per capita growth is strongly non-linear in Aedes aegypti (Linnaeus), Aedes albopictus (Skuse), and Aedes triseriatus (Say) mosquitoes. Components of population growth (survivorship, development time, adult size) are also nonlinearly related to initial density. The causes and consequences of this nonlinearity are likely to be important issues for population and community ecology.
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Affiliation(s)
- Logan A Sauers
- School of Biological Sciences, Illinois State University, 251 S. School St., Normal, IL, 61761, USA.
| | - Kelsey E Hawes
- School of Biological Sciences, Illinois State University, 251 S. School St., Normal, IL, 61761, USA
| | - Steven A Juliano
- School of Biological Sciences, Illinois State University, 251 S. School St., Normal, IL, 61761, USA
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24
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Paterson JT, Proffitt KM, Rotella JJ. Incorporating vital rates and harvest into stochastic population models to forecast elk population dynamics. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | - Kelly M. Proffitt
- Montana Department of Fish, Wildlife, and Parks Bozeman 59718 MT USA
| | - Jay J. Rotella
- Montana State University 310 Lewis Hall Bozeman MT 59718 USA
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25
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Nonlinear spatial and temporal decomposition provides insight for climate change effects on sub-Arctic herbivore populations. Oecologia 2022; 198:889-904. [PMID: 35325288 DOI: 10.1007/s00442-022-05150-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Accepted: 03/06/2022] [Indexed: 10/18/2022]
Abstract
Global temperatures are increasing, affecting timing and availability of vegetation along with relationships between plants and their consumers. We examined the effect of population density, herd body condition in the previous year, elevation, plant productivity and phenology, snow, and winter onset on juvenile body mass in 63 semi-domesticated populations of Rangifer tarandus throughout Norway using spatiotemporal generalized additive models (GAMs) and varying coefficient models (VCMs). Optimal climate windows were calculated at both the regional and national level using a novel nonlinear climate window algorithm optimized for prediction. Spatial and temporal variation in effects of population and environmental predictors were considered using a model including covariates decomposed into spatial, temporal, and residual components. The performance of this decomposed model was compared to spatiotemporal GAMs and VCMs. The decomposed model provided the best fit and lowest prediction errors. A positive effect of herd body condition in the previous year explained most of the deviance in calf body mass, followed by a more complex effect of population density. A negative effect of timing of spring and positive effect of winter onset on juvenile body mass suggested that a snow free season was positive for juvenile body mass growth. Our findings suggest early spring onset and later winter permanent snow cover as reinforcers of early-life conditions which support more robust reindeer populations. Our methodological improvements for climate window analyses and effect size measures for decomposed variables provide important contributions to account for, measure, and interpret nonlinear relationships between climate and animal populations at large scales.
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26
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Plaisir CA, King WJ, Forsyth DM, Festa-Bianchet M. Effects of rainfall, forage biomass, and population density, on survival and growth of juvenile kangaroos. J Mammal 2022. [DOI: 10.1093/jmammal/gyab132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
A central goal of ecology is to understand how environmental variation affects populations. Long-term studies of marked individuals can quantify the effects of environmental variation on key life-history traits. We monitored the survival and growth of 336 individually marked juvenile eastern grey kangaroos (Macropus giganteus), a large herbivore living in a seasonal but unpredictable environment. During our 12-year study, the population experienced substantial variation in rainfall, forage biomass, and density. We used structural equation modeling to determine how variation in temperature and rainfall affected juvenile survival and growth through its effect on forage biomass and population density. Independently of population density, forage biomass had strong positive effects on survival from 10 to 21 months. At low population density, forage biomass also had a positive effect on skeletal growth to 26 months. Increasing maternal body condition improved rearing success for daughters but not for sons. High population density reduced skeletal growth to 26 months for both sexes. Rainfall had an increasingly positive effect on forage biomass at high temperatures, indicating a seasonal effect on food availability. Our study reveals interacting effects of environmental variation on juvenile survival and growth for a large mammal with a conservative reproductive strategy that experiences substantial stochasticity in food availability.
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Affiliation(s)
- Charles-Alexandre Plaisir
- Département de Biologie, Université de Sherbrooke, 2500, Boulevard de l’Université, Sherbrooke, QC J1K 2R1, Canada
| | - Wendy J King
- Département de Biologie, Université de Sherbrooke, 2500, Boulevard de l’Université, Sherbrooke, QC J1K 2R1, Canada
- Research School of Biology, Australian National University, 134, Linnaeus Way, Acton, ACT 2601, Australia
| | - David M Forsyth
- Vertebrate Pest Research Unit, NSW Department of Primary Industries, 1447 Forest Road, Orange, NSW 2800, Australia
- School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Marco Festa-Bianchet
- Département de Biologie, Université de Sherbrooke, 2500, Boulevard de l’Université, Sherbrooke, QC J1K 2R1, Canada
- Research School of Biology, Australian National University, 134, Linnaeus Way, Acton, ACT 2601, Australia
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27
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Cristescu B, Elbroch LM, Dellinger JA, Binder W, Wilmers CC, Wittmer HU. Kill rates and associated ecological factors for an apex predator. Mamm Biol 2022. [DOI: 10.1007/s42991-022-00240-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AbstractKill rates and functional responses are fundamental to the study of predator ecology and the understanding of predatory-prey dynamics. As the most widely distributed apex predator in the western hemisphere, pumas (Puma concolor) have been well studied, yet a synthesis of their kill rates is currently lacking. We reviewed the literature and compiled data on sex- and age-specific kill rate estimates of pumas on ungulates, and conducted analyses aimed at understanding ecological factors explaining the observed spatial variation. Kill rate studies on pumas, while numerous, were primarily conducted in Temperate Conifer Forests (< 10% of puma range), revealing a dearth of knowledge across much of their range, especially from tropical and subtropical habitats. Across studies, kill rates in ungulates/week were highest for adult females with kitten(s) (1.24 ± 0.41 ungulates/week) but did not vary significantly between adult males (0.84 ± 0.18) and solitary adult females (0.99 ± 0.26). Kill rates in kg/day differed only marginally among reproductive classes. Kill rates of adult pumas increased with ungulate density, particularly for males. Ungulate species richness had a weak negative association with adult male kill rates. Neither scavenger richness, puma density, the proportion of non-ungulate prey in the diet, nor regional human population density had a significant effect on ungulate kill rates, but additional studies and standardization would provide further insights. Our results had a strong temperate-ecosystem bias highlighting the need for further research across the diverse biomes pumas occupy to fully interpret kill rates for the species. Data from more populations would also allow for multivariate analyses providing deeper inference into the ecological and behavioural factors driving kill rates and functional responses of pumas, and apex predators in general.
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Martin HW, Hebblewhite M, Merrill EH. Large herbivores in a partially migratory population search for the ideal free home. Ecology 2022; 103:e3652. [PMID: 35084736 PMCID: PMC10162400 DOI: 10.1002/ecy.3652] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 09/10/2021] [Accepted: 10/26/2021] [Indexed: 11/07/2022]
Abstract
Migration is a tactic used across taxa to access resources in temporally heterogenous landscapes. Populations that migrate can attain higher abundances because such movements allow access to higher quality resources, or reduction in predation risk resulting in increased fitness. However, most migratory species occur in partially migratory populations, a mix of migratory and non-migratory individuals. It is thought that the portion of migrants in a partial migration population is maintained either through 1) a population-level evolutionary stable state where counteracting density-dependent vital rates act on migrants and residents to balance fitness, or 2) conditional migration, where the propensity to migrate is influenced by the individual's state. However, in many respects, migration is also a form of habitat selection and the proportion of migrants and residents may be the result of density-dependent habitat selection. Here, we test whether the theory of Ideal Free Distribution (IFD) can explain the coexistence of different migratory tactics in a partially migratory population. IFD predicts individuals exhibit density-dependent vital rates and select different migratory tactics to maximize individual fitness resulting in equal fitness (λ) between tactics. We tested the predictions of IFD in a partially migratory elk population that declined by 70% with 19 years of demographic data and migratory tactic switching rates from >300 individuals. We found evidence of density dependence for resident pregnancy and adult female survival providing a fitness incentive to switch tactics. Despite differences in vital rates between migratory tactics, mean λ (fitness) was equal. However, as predicted by the IFD, individuals switched tactics toward those of higher fitness. Our analysis reveals that partial migration may be driven by tactic selection that follows the ideal free distribution. These findings reinforce that migration across taxa may be a polymorphic behavior in large herbivores where migratory tactic selection is determined by differential costs and benefits, mediated by density-dependence.
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Affiliation(s)
- Hans W Martin
- Wildlife Biology Program, W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, Montana, USA
| | - Mark Hebblewhite
- Wildlife Biology Program, W.A. Franke College of Forestry and Conservation, University of Montana, Missoula, Montana, USA
| | - Evelyn H Merrill
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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Peláez M, San Miguel A, Rodríguez‐Vigal C, Moreno‐Gómez Á, García del Rincón A, Perea García‐Calvo R. Using retrospective life tables to assess the effect of extreme climatic conditions on ungulate demography. Ecol Evol 2022; 12:e8218. [PMID: 35126996 PMCID: PMC8794714 DOI: 10.1002/ece3.8218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/16/2021] [Accepted: 09/19/2021] [Indexed: 12/03/2022] Open
Abstract
In Mediterranean areas, severe drought events are expected to intensify in forthcoming years as a consequence of climate change. These events may increase physiological and reproductive stress of wild populations producing demographic changes and distribution shifts. We used retrospective life tables to understand demographic changes on a wild population after severe drought events. We studied the impact of two extreme events (2003 and 2005) on the population dynamics of our model species, the red deer (Cervus elaphus). During both years, population density was high (40 and 36 ind/100 ha, respectively). Thus, we reconstructed retrospectively the age structure of the female part of the population for the period 2000-2010 by using data of known-age individuals culled during the period 2000-2019 (n = 4176). Also, based on previous study results, we aimed to validate this methodology. Both extremely dry years, 2003 and 2005, produced marked and lasting cohort effects on population demography. Age pyramid the following years (2004 and 2006) revealed that the extreme drought caused the female fawn cohort to be similar or even smaller than the yearling cohort. Furthermore, these cohort effects were still perceptible 3 years after these severe events. Results agree with previous findings that showed a negative effect of severe drought events on female pregnancy rates and conception dates. Although simple, this study provides an empirical quantification of the demographic effects of severe drought events for a wild population which might be useful to understand future demographic changes under the context of climate change.
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Affiliation(s)
- Marta Peláez
- Departamento de Sistemas y Recursos NaturalesUniversidad Politécnica de MadridMadridSpain
| | - Alfonso San Miguel
- Departamento de Sistemas y Recursos NaturalesUniversidad Politécnica de MadridMadridSpain
| | | | - Ángel Moreno‐Gómez
- Centro de Quintos de MoraToledoSpain
- Organismo Autónomo Parques NacionalesMadridSpain
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Behavioural Indicators of Intra- and Inter-Specific Competition: Sheep Co-Grazing with Guanaco in the Patagonian Steppe. Animals (Basel) 2021; 11:ani11113333. [PMID: 34828064 PMCID: PMC8614449 DOI: 10.3390/ani11113333] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/14/2021] [Accepted: 11/17/2021] [Indexed: 11/17/2022] Open
Abstract
Simple Summary In extensive livestock ranching, where animals are maintained at high numbers, competition between individuals is expected, but not generally assumed. To compensate for reduced food availability, herbivores modify their feeding behaviour, which can be used as an indicator of competition. We investigated behavioural changes of domestic sheep in Chilean Patagonia in response to herd size, food availability, and the presence of a wild competitor, the guanaco, considered a problem for sheep production by ranchers. Large sheep herds were associated with a decrease in sheep grazing, while food availability increased time spent feeding. Guanaco had no effect on sheep behaviours. Behavioural changes were mostly associated with competition between individual sheep and not with guanaco. We suggest that to improve sheep production, ranchers should focus on sheep management at appropriate herd sizes according to grassland capacities. Abstract In extensive livestock production, high densities may inhibit regulation processes, maintaining high levels of intraspecific competition over time. During competition, individuals typically modify their behaviours, particularly feeding and bite rates, which can therefore be used as indicators of competition. Over eight consecutive seasons, we investigated if variation in herd density, food availability, and the presence of a potential competitor, the guanaco (Lama guanicoe), was related with behavioural changes in domestic sheep in Chilean Patagonia. Focal sampling, instantaneous scan sampling, measures of bite and movement rates were used to quantify behavioural changes in domestic sheep. We found that food availability increased time spent feeding, while herd density was associated with an increase in vigilant behaviour and a decrease in bite rate, but only when food availability was low. Guanaco presence appeared to have no impact on sheep behaviour. Our results suggest that the observed behavioural changes in domestic sheep are more likely due to intraspecific competition rather than interspecific competition. Consideration of intraspecific competition where guanaco and sheep co-graze on pastures could allow management strategies to focus on herd density, according to rangeland carrying capacity.
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Wilson M, Coulson G. Early warning signs of population irruptions in Eastern Grey Kangaroo (
Macropus giganteus
). ECOLOGICAL MANAGEMENT & RESTORATION 2021. [DOI: 10.1111/emr.12450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
A recent study published in The Lancet predicts a remarkable drop in population numbers following a peak that will be reached by 2064. A unique feature of the upcoming population drop is that it will be almost exclusively caused by decreased reproduction, rather than factors that increase rates of mortality. The reasons for decreased reproduction are also unique, as, unlike previous centuries, limited reproduction today is hardly due to a shortage in resources. In other words, the predicted population drop is almost exclusively due to changes in reproductive behavior and reproductive physiology. Today, global changes in reproductive behavior are mostly explained by social sciences in a framework of demographic transition hypotheses, while changes in reproductive physiology are usually attributed to effects of endocrine-disrupting pollutants. This review outlines a complementary/alternative hypothesis, which connects reproductive trends with population densities. Numerous wildlife and experimental studies of a broad range of animal species have demonstrated that reproductive behavior and reproductive physiology are negatively controlled via endocrine and neural signaling in response to increasing population densities. The causal chain of this control system, although not fully understood, includes suppression of every level of hypothalamic-pituitary-gonadal cascade by hypothalamic-pituitary-adrenal axis, activated in response to increasing stress of social interactions. This paper discusses evidence in support of a hypothesis that current trends in reproductive physiology and behavior may be partly explained by increasing population densities. Better understanding of the causal chain involved in reproduction suppression by population density-related factors may help in developing interventions to treat infertility and other reproductive conditions.
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Affiliation(s)
- Alexander Suvorov
- Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, Amherst, MA 01003, USA
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Pélabon C, Côté SD, Festa‐Bianchet M, Gaillard J, Garel M, Lemaître J, Loison A, Tidière M, Toïgo C. Effects of population density on static allometry between horn length and body mass in mountain ungulates. OIKOS 2021. [DOI: 10.1111/oik.08726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christophe Pélabon
- Dept of Biology, Centre for Biodiversity Dynamics, Norwegian Univ. of Science and Technology Trondheim Norway
| | - Steeve D. Côté
- Dépt de Biologie and Centre d'Etudes Nordiques, Univ. Laval Québec QC Canada
| | | | - Jean‐Michel Gaillard
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, Univ. de Lyon, Université Lyon 1, CNRS Villeurbanne France
| | - Mathieu Garel
- Office Français de la Biodiversité, Unité Ongulés Sauvages, ZI Mayencin Gières France
| | - Jean‐Francois Lemaître
- Laboratoire de Biométrie et Biologie Evolutive, UMR5558, Univ. de Lyon, Université Lyon 1, CNRS Villeurbanne France
| | - Anne Loison
- Univ. Grenoble Alpes, Univ. Savoie Mont‐Blanc, CNRS, LECA Grenoble France
| | - Morgane Tidière
- Species360 Conservation Science Alliance Bloomington Minnesota USA
- Interdisciplinary Centre on Population Dynamics, Dept of Biology, Univ. of Southern Denmark Odense M Denmark
| | - Carole Toïgo
- Office Français de la Biodiversité, Unité Ongulés Sauvages, ZI Mayencin Gières France
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Lambert S, Thébault A, Rossi S, Marchand P, Petit E, Toïgo C, Gilot-Fromont E. Targeted strategies for the management of wildlife diseases: the case of brucellosis in Alpine ibex. Vet Res 2021; 52:116. [PMID: 34521471 PMCID: PMC8439036 DOI: 10.1186/s13567-021-00984-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 07/12/2021] [Indexed: 11/10/2022] Open
Abstract
The management of infectious diseases in wildlife reservoirs is challenging and faces several limitations. However, detailed knowledge of host-pathogen systems often reveal heterogeneity among the hosts' contribution to transmission. Management strategies targeting specific classes of individuals and/or areas, having a particular role in transmission, could be more effective and more acceptable than population-wide interventions. In the wild population of Alpine ibex (Capra ibex-a protected species) of the Bargy massif (French Alps), females transmit brucellosis (Brucella melitensis) infection in ~90% of cases, and most transmissions occur in the central spatial units ("core area"). Therefore, we expanded an individual-based model, developed in a previous study, to test whether strategies targeting females or the core area, or both, would be more effective. We simulated the relative efficacy of realistic strategies for the studied population, combining test-and-remove (euthanasia of captured animals with seropositive test results) and partial culling of unmarked animals. Targeting females or the core area was more effective than untargeted management options, and strategies targeting both were even more effective. Interestingly, the number of ibex euthanized and culled in targeted strategies were lower than in untargeted ones, thus decreasing the conservation costs while increasing the sanitary benefits. Although there was no silver bullet for the management of brucellosis in the studied population, targeted strategies offered a wide range of promising refinements to classical sanitary measures. We therefore encourage to look for heterogeneity in other wildlife diseases and to evaluate potential strategies for improving management in terms of efficacy but also acceptability.
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Affiliation(s)
- Sébastien Lambert
- Laboratoire de Biométrie et Biologie Évolutive UMR 5558, CNRS, Université Lyon 1, Université de Lyon, Villeurbanne, France. .,Department of Pathobiology and Population Sciences, Royal Veterinary College, University of London, Hatfield, UK.
| | - Anne Thébault
- Direction de l'évaluation des Risques, Agence Nationale de Sécurité Sanitaire, de l'Alimentation, de l'Environnement et du Travail (Anses), Maisons-Alfort, France
| | - Sophie Rossi
- Unité Sanitaire de La Faune, Office Français de la Biodiversité (OFB), Gap, France
| | - Pascal Marchand
- Unité Ongulés Sauvages, Office Français de la Biodiversité (OFB), Juvignac, France
| | - Elodie Petit
- Unité Sanitaire de La Faune, Office Français de la Biodiversité (OFB), Sévrier, France.,Laboratoire de Biométrie et Biologie Évolutive UMR 5558, CNRS, VetAgro Sup, Université de Lyon, Villeurbanne, France
| | - Carole Toïgo
- Unité Ongulés Sauvages, Office Français de La Biodiversité (OFB), Gières, France
| | - Emmanuelle Gilot-Fromont
- Laboratoire de Biométrie et Biologie Évolutive UMR 5558, CNRS, VetAgro Sup, Université de Lyon, Villeurbanne, France
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35
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Scorolli AL. Feral Horse Population Model and Body Condition: Useful Management Tools in Tornquist Park, Argentina? J Wildl Manage 2021. [DOI: 10.1002/jwmg.21965] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Espunyes J, Serrano E, Chaves S, Bartolomé J, Menaut P, Albanell E, Marchand P, Foulché K, Garel M. Positive effect of spring advance on the diet quality of an alpine herbivore. Integr Zool 2021; 17:78-92. [PMID: 34223702 DOI: 10.1111/1749-4877.12572] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Changes in vegetation phenology related to global warming are having alarming effects on the life history traits of many herbivore species. Such changes are particularly critical in alpine ecosystems, where strong climate limitations on plant growth make seasonal synchronization imperative for the growth, reproduction and survival of herbivores. However, despite the pivotal role of resource-use strategies on the performances of such species, few studies have explicitly assessed the mechanistic impact of climate change on their diets. We aimed to fill this gap by studying the effect of spring onset on the dietary composition and quality of a medium-size alpine herbivore while considering density-dependent processes and age- and sex-specific differences in foraging behavior. Using an exceptional, long-term (24 years) direct individual-based dietary monitoring of a Pyrenean chamois population (Rupicapra pyrenaica pyrenaica), we showed that ongoing earlier onsets of spring are leading to an earlier access to high-quality forage and therefore a higher diet quality at a fixed date, without apparent changes in diet composition. We also showed that at high densities, intraspecific competition reduced diet quality by driving animals to feed more on woody plants and less on nutritious forbs and graminoids. By assessing the mechanistic effects of global warming on the dietary patterns of species at the center of trophic networks, this study is an essential step for predictive models aiming at understanding the ongoing ecosystem consequences of the global climatic crisis.
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Affiliation(s)
- Johan Espunyes
- Wildlife Ecology and Health group (WE&H) i Servei d'Ecopatologia de la Fauna Salvatge (SEFaS), Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain.,Wildlife Conservation Medicine Research Group (WildCoM), Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain.,Research and Conservation Department, Zoo de Barcelona, Barcelona, Spain
| | - Emmanuel Serrano
- Wildlife Ecology and Health group (WE&H) i Servei d'Ecopatologia de la Fauna Salvatge (SEFaS), Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Sara Chaves
- Wildlife Ecology and Health group (WE&H) i Servei d'Ecopatologia de la Fauna Salvatge (SEFaS), Department of Animal Medicine and Surgery, Faculty of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain.,Group of Ruminant Research (G2R), Department of Animal and Food Science, Faculty of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Jordi Bartolomé
- Group of Ruminant Research (G2R), Department of Animal and Food Science, Faculty of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Pierre Menaut
- French Agency for Biodiversity, Direction Régionale Occitanie, Service d'Appui aux Acteurs et Mobilisation du Territoire, Villeneuve de Rivière, France
| | - Elena Albanell
- Group of Ruminant Research (G2R), Department of Animal and Food Science, Faculty of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Pascal Marchand
- French Agency for Biodiversity, Direction de la Recherche et Appui Scientifique, Unité Ongulés Sauvages, Gières, France
| | - Kévin Foulché
- French Agency for Biodiversity, Direction Régionale Occitanie, Service d'Appui aux Acteurs et Mobilisation du Territoire, Villeneuve de Rivière, France
| | - Mathieu Garel
- French Agency for Biodiversity, Direction de la Recherche et Appui Scientifique, Unité Ongulés Sauvages, Gières, France
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Hin V, Harwood J, de Roos AM. Density dependence can obscure nonlethal effects of disturbance on life history of medium-sized cetaceans. PLoS One 2021; 16:e0252677. [PMID: 34081741 PMCID: PMC8174747 DOI: 10.1371/journal.pone.0252677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 05/20/2021] [Indexed: 11/19/2022] Open
Abstract
Nonlethal disturbance of animals can cause behavioral and physiological changes that affect individual health status and vital rates, with potential consequences at the population level. Predicting these population effects remains a major challenge in ecology and conservation. Monitoring fitness-related traits may improve detection of upcoming population changes, but the extent to which individual traits are reliable indicators of disturbance exposure is not well understood, especially for populations regulated by density dependence. Here we study how density dependence affects a population’s response to disturbance and modifies the disturbance effects on individual health and vital rates. We extend an energy budget model for a medium-sized cetacean (the long-finned pilot whale Globicephala melas) to an individual-based population model in which whales feed on a self-replenishing prey base and disturbance leads to cessation of feeding. In this coupled predator-prey system, the whale population is regulated through prey depletion and the onset of yearly repeating disturbances on the whale population at carrying capacity decreased population density and increased prey availability due to reduced top-down control. In populations faced with multiple days of continuous disturbance each year, female whales that were lactating their first calf experienced increased mortality due to depletion of energy stores. However, increased prey availability led to compensatory effects and resulted in a subsequent improvement of mean female body condition, mean age at first reproduction and higher age-specific reproductive output. These results indicate that prey-mediated density dependence can mask negative effects of disturbance on fitness-related traits and vital rates, a result with implications for the monitoring and management of marine mammal populations.
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Affiliation(s)
- Vincent Hin
- Department of Theoretical and Computational Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
- * E-mail:
| | - John Harwood
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, United Kingdom
| | - André M. de Roos
- Department of Theoretical and Computational Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
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Jesmer BR, Kauffman MJ, Courtemanch AB, Kilpatrick S, Thomas T, Yost J, Monteith KL, Goheen JR. Life-history theory provides a framework for detecting resource limitation: a test of the Nutritional Buffer Hypothesis. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02299. [PMID: 33428817 DOI: 10.1002/eap.2299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 07/10/2020] [Accepted: 10/06/2020] [Indexed: 06/12/2023]
Abstract
For ungulates and other long-lived species, life-history theory predicts that nutritional reserves are allocated to reproduction in a state-dependent manner because survival is highly conserved. Further, as per capita food abundance and nutritional reserves decline (i.e., density dependence intensifies), reproduction and recruitment become increasingly sensitive to weather. Thus, the degree to which weather influences vital rates should be associated with proximity to nutritional carrying capacity-a notion that we refer to as the Nutritional Buffer Hypothesis. We tested the Nutritional Buffer Hypothesis using six moose (Alces alces) populations that varied in calf recruitment (33-69 calves/100 cows). We predicted that populations with high calf recruitment were nutritionally buffered against the effects of unfavorable weather, and thus were below nutritional carrying capacity. We applied a suite of tools to quantify habitat and nutritional condition of each population and found that increased browse condition, forage quality, and body fat were associated with increased pregnancy and calf recruitment, thereby providing multiple lines of evidence that declines in calf recruitment were underpinned by resource limitation. From 2001 to 2015, recruitment was more sensitive to interannual variation in weather (e.g., winter severity, drought) and plant phenology (e.g., duration of spring) for populations with reduced browse condition, forage quality, and body fat, suggesting these populations lacked the nutritional reserves necessary to buffer demographic performance against the effects of unfavorable weather. Further, average within-population calf recruitment was determined by regional climatic variation, suggesting that the pattern of reduced recruitment near the southern range boundary of moose stems from an interaction between climate and resource limitation. When coupled with information on habitat, nutrition, weather, and climate, life-history theory provides a framework to estimate nutritional limitation, proximity to nutritional carrying capacity, and impacts of climate change for ungulates.
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Affiliation(s)
- Brett R Jesmer
- Program in Ecology, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
- Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
- Center for Biodiversity and Global Change, Yale University, New Haven, Connecticut, 06520, USA
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, 06520, USA
| | - Matthew J Kauffman
- Program in Ecology, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
- U.S. Geological Survey, Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
| | | | - Steve Kilpatrick
- Wyoming Wild Sheep Foundation, P.O. Box 666, Cody, Wyoming, 82414, USA
| | - Timothy Thomas
- Wyoming Game and Fish Department, P.O. Box 6249, Sheridan, Wyoming, 82801, USA
| | - Jeff Yost
- Colorado Parks and Wildlife, P.O. Box 775777, Steamboat Springs, Colorado, 80487, USA
| | - Kevin L Monteith
- Program in Ecology, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
- Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
- Haub School of Environment and Natural Resources, University of Wyoming, Laramie, Wyoming, 82072, USA
| | - Jacob R Goheen
- Program in Ecology, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, 82071, USA
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Donini V, Pedrotti L, Ferretti F, Corlatti L. Disentangling demographic effects of red deer on chamois population dynamics. Ecol Evol 2021; 11:8264-8280. [PMID: 34188885 PMCID: PMC8216891 DOI: 10.1002/ece3.7657] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/19/2021] [Accepted: 04/23/2021] [Indexed: 11/12/2022] Open
Abstract
Investigating the impact of ecological factors on sex- and age-specific vital rates is essential to understand animal population dynamics and detect the potential for interactions between sympatric species. We used block count data and autoregressive linear models to investigate variation in birth rate, kid survival, female survival, and male survival in a population of Alpine chamois Rupicapra rupicapra rupicapra monitored over 27 years within the Stelvio National Park, Central Italian Alps, as function of climatic variables, density dependence, and interspecific competition with red deer Cervus elaphus. We also used path analysis to assess the indirect effect of deer abundance on chamois growth rate mediated by each demographic parameter. Based on previous findings, we predicted that birth rate at [t] would negatively relate to red deer abundance at year [t - 1]; survival rates between [t] and [t + 1] would negatively relate to red deer abundance at year [t - 1] and to the interactive effect of winter precipitation at [t + 1] and chamois density at [t]. Our results showed that birth rate was positively related to spring-summer precipitation in the previous year, but this effect was hampered by increasing red deer abundance. Kid and female survival rates were negatively related to the combined effect of chamois abundance and winter precipitation. Male and female survival rates were negatively related to lagged red deer abundance. The path analysis supported a negative indirect effect of red deer abundance on chamois growth rate mediated by birth rate and female survival. Our results suggest that chamois population dynamics was largely explained by the synergistic effect of density dependence and winter harshness, as well as by interspecific competition with red deer, whose effects were seemingly stronger on the kid-female segment of the population.
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Affiliation(s)
- Valerio Donini
- Stelvio National Park, Sustainable Development and Protected Areas ServiceAutonomous Province of TrentoCogolo di PejoItaly
- Stelvio National ParkBormioItaly
| | - Luca Pedrotti
- Stelvio National Park, Sustainable Development and Protected Areas ServiceAutonomous Province of TrentoCogolo di PejoItaly
- Stelvio National ParkBormioItaly
| | | | - Luca Corlatti
- Stelvio National ParkBormioItaly
- Chair of Wildlife Ecology and ManagementUniversity of FreiburgFreiburgGermany
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40
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Bowyer RT, Bleich VC, Krausman PR, Gaillard JM. Editorial: Advances in Ungulate Ecology. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.675265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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41
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Katzenberger J, Gottschalk E, Balkenhol N, Waltert M. Density‐dependent age of first reproduction as a key factor for population dynamics: stable breeding populations mask strong floater declines in a long‐lived raptor. Anim Conserv 2021. [DOI: 10.1111/acv.12687] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jakob Katzenberger
- Dachverband Deutscher Avifaunisten (DDA) e.V. Münster Germany
- Workgroup on Endangered Species J.F. Blumenbach Institute of Zoology and Anthropology University of Goettingen Göttingen Germany
| | - Eckhard Gottschalk
- Workgroup on Endangered Species J.F. Blumenbach Institute of Zoology and Anthropology University of Goettingen Göttingen Germany
| | - Niko Balkenhol
- Wildlife Sciences University of Goettingen Göttingen Germany
| | - Matthias Waltert
- Workgroup on Endangered Species J.F. Blumenbach Institute of Zoology and Anthropology University of Goettingen Göttingen Germany
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Šturm MB, Smith S, Ganbaatar O, Buuveibaatar B, Balint B, Payne JC, Voigt CC, Kaczensky P. Isotope analysis combined with DNA barcoding provide new insights into the dietary niche of khulan in the Mongolian Gobi. PLoS One 2021; 16:e0248294. [PMID: 33780458 PMCID: PMC8006982 DOI: 10.1371/journal.pone.0248294] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 02/23/2021] [Indexed: 11/26/2022] Open
Abstract
With increasing livestock numbers, competition and avoidance are increasingly shaping resource availability for wild ungulates. Shifts in the dietary niche of wild ungulates are likely and can be expected to negatively affect their fitness. The Mongolian Gobi constitutes the largest remaining refuge for several threatened ungulates, but unprecedentedly high livestock numbers are sparking growing concerns over rangeland health and impacts on threatened ungulates like the Asiatic wild ass (khulan). Previous stable isotope analysis of khulan tail hair from the Dzungarian Gobi suggested that they graze in summer but switch to a poorer mixed C3 grass / C4 shrub diet in winter, most likely in reaction to local herders and their livestock. Here we attempt to validate these findings with a different methodology, DNA metabarcoding. Further, we extend the scope of the original study to the South Gobi Region, where we expect higher proportions of low-quality browse in the khulan winter diet due to a higher human and livestock presence. Barcoding confirmed the assumptions behind the seasonal diet change observed in the Dzungarian Gobi isotope data, and new isotope analysis revealed a strong seasonal pattern and higher C4 plant intake in the South Gobi Region, in line with our expectations. However, DNA barcoding revealed C4 domination of winter diet was due to C4 grasses (rather than shrubs) for the South Gobi Region. Slight climatic differences result in regional shifts in the occurrence of C3 and C4 grasses and shrubs, which do not allow for an isotopic separation along the grazer-browser continuum over the entire Gobi. Our findings do not allow us to confirm human impacts upon dietary preferences in khulan as we lack seasonal samples from the South Gobi Region. However, these data provide novel insight into khulan diet, raise new questions about plant availability versus preference, and provide a cautionary tale about indirect analysis methods if used in isolation or extrapolated to the landscape level. Good concordance between relative read abundance of C4 genera from barcoding and proportion of C4 plants from isotope analysis adds to a growing body of evidence that barcoding is a promising quantitative tool to understand resource partitioning in ungulates.
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Affiliation(s)
- Martina Burnik Šturm
- Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Steve Smith
- Konrad-Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Oyunsaikhan Ganbaatar
- Great Gobi B Strictly Protected Area Administration, Takhin Tal, Gobi Altai Province, Mongolia
- Department of Zoology, School of Biology and Biotechnology, National University of Mongolia, Ulaanbaatar, Mongolia
| | | | - Boglarka Balint
- Great Gobi B Strictly Protected Area Administration, Takhin Tal, Gobi Altai Province, Mongolia
| | - John C. Payne
- Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | | | - Petra Kaczensky
- Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
- Norwegian Institute for Nature Research–NINA, Trondheim, Norway
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Traill LW, Plard F, Gaillard JM, Coulson T. Can we use a functional trait to construct a generalized model for ungulate populations? Ecology 2021; 102:e03289. [PMID: 33484576 DOI: 10.1002/ecy.3289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 08/18/2020] [Accepted: 11/12/2020] [Indexed: 11/09/2022]
Abstract
Ecologists have long desired predictive models that allow inference on population dynamics, where detailed demographic data are unavailable. Integral projection models (IPMs) allow both demographic and phenotypic outcomes at the level of the population to be predicted from the distribution of a functional trait, like body mass. In species where body mass markedly influences demographic rates, as is the rule among mammals, then IPMs provide not only opportunity to assess the population responses to a given environment, but also improve our understanding of the complex interplay between traits and demographic outcomes. Here, we develop a body-mass-based approach to constructing generalized, predictive IPMs for species of ungulates covering a broad range of body size (25-400 kg). Despite our best efforts, we found that a reliable and general, functional, trait-based model for ungulates was unattainable even after accounting for among-species variation in both age at first reproduction and litter size. We attribute this to the diversity of reproductive tactics among similar-sized species of ungulates, and to the interplay between density-dependent and environmental factors that shape demographic parameters independent of mass at the local scale. These processes thus drive population dynamics and cannot be ignored. Environmental context generally matters in population ecology, and our study shows this may be the case for functional traits in vertebrate populations.
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Affiliation(s)
- Lochran W Traill
- Schoool of Biological and Environmental Sciences, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF, United Kingdom.,School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Floriane Plard
- Biométrie et Biologie Évolutive, UMR-CNRS 5558, Université de Lyon 1, Villeurbanne, France
| | - Jean-Michel Gaillard
- Biométrie et Biologie Évolutive, UMR-CNRS 5558, Université de Lyon 1, Villeurbanne, France
| | - Tim Coulson
- Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, Oxford, OX1 3PS, United Kingdom
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Proffitt KM, Courtemanch AB, Dewey SR, Lowrey B, McWhirter DE, Monteith K, Paterson JT, Rotella J, White PJ, Garrott RA. Regional variability in pregnancy and survival rates of Rocky Mountain bighorn sheep. Ecosphere 2021. [DOI: 10.1002/ecs2.3410] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Kelly M. Proffitt
- Montana Department of Fish Wildlife, and Parks 1400 South 19th Avenue Bozeman Montana59718USA
| | | | - Sarah R. Dewey
- Grand Teton National Park P.O. Box 170 Moose Wyoming83012USA
| | - Blake Lowrey
- Fish and Wildlife Ecology and Management Program Department of Ecology Montana State University 310 Lewis Hall Bozeman Montana59717USA
| | | | - Kevin.L. Monteith
- Haub School of Environment and Natural Resources Wyoming Cooperative Fish and Wildlife Research Unit Department of Zoology and Physiology University of Wyoming 804 East Fremont Street Laramie Wyoming82072USA
| | - J. Terrill Paterson
- Fish and Wildlife Ecology and Management Program Department of Ecology Montana State University 310 Lewis Hall Bozeman Montana59717USA
| | - Jay Rotella
- Fish and Wildlife Ecology and Management Program Department of Ecology Montana State University 310 Lewis Hall Bozeman Montana59717USA
| | - Patrick J. White
- Yellowstone Center for Resources Yellowstone National Park National Park Service Mammoth Wyoming82190USA
| | - Robert A. Garrott
- Fish and Wildlife Ecology and Management Program Department of Ecology Montana State University 310 Lewis Hall Bozeman Montana59717USA
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Bond ML, Lee DE, Farine DR, Ozgul A, König B. Sociability increases survival of adult female giraffes. Proc Biol Sci 2021; 288:20202770. [PMID: 33563118 DOI: 10.1098/rspb.2020.2770] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Studies increasingly show that social connectedness plays a key role in determining survival, in addition to natural and anthropogenic environmental factors. Few studies, however, integrated social, non-social and demographic data to elucidate what components of an animal's socio-ecological environment are most important to their survival. Female giraffes (Giraffa camelopardalis) form structured societies with highly dynamic group membership but stable long-term associations. We examined the relative contributions of sociability (relationship strength, gregariousness and betweenness), together with those of the natural (food sources and vegetation types) and anthropogenic environment (distance from human settlements), to adult female giraffe survival. We tested predictions about the influence of sociability and natural and human factors at two social levels: the individual and the social community. Survival was primarily driven by individual- rather than community-level social factors. Gregariousness (the number of other females each individual was observed with on average) was most important in explaining variation in female adult survival, more than other social traits and any natural or anthropogenic environmental factors. For adult female giraffes, grouping with more other females, even as group membership frequently changes, is correlated with better survival, and this sociability appears to be more important than several attributes of their non-social environment.
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Affiliation(s)
- M L Bond
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Wild Nature Institute, Concord, NH, USA
| | - D E Lee
- Wild Nature Institute, Concord, NH, USA.,Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - D R Farine
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Department of Collective Behavior, Max Planck Institute of Animal Behavior, Konstanz, Germany.,Center for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany
| | - A Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - B König
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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Oates BA, Monteith KL, Goheen JR, Merkle JA, Fralick GL, Kauffman MJ. Detecting Resource Limitation in a Large Herbivore Population Is Enhanced With Measures of Nutritional Condition. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2020.522174] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Resource limitation at the population level is a function of forage quality and its abundance relative to its per capita availability, which in turn, determines nutritional condition of individuals. Effects of resource limitation on population dynamics in ungulates often occur through predictable and sequential changes in vital rates, which can enable assessments of how resource limitation influences population growth. We tested theoretical predictions of bottom-up (i.e., resource limitation) forcing on moose (Alces alces) through the lens of vital rates by quantifying the relative influence of intrinsic measures of nutritional condition and extrinsic measures of remotely sensed environmental data on demographic rates. We measured rates of pregnancy, parturition, juvenile, and adult survival for 82 adult females in a population where predators largely were absent. Life stage simulation analyses (LSAs) indicated that interannual fluctuations in adult survival contributed to most of the variability in λ. We then extended the LSA to estimate vital rates as a function of bottom-up covariates to evaluate their influence on λ. We detected weak signatures of effects from environmental covariates that were remotely sensed and spatially explicit to each seasonal range. Instead, nutritional condition strongly influenced rates of pregnancy, parturition, and overwinter survival of adults, clearly implicating resource limitation on λ. Our findings depart from the classic life-history paradigm of population dynamics in ungulates in that adult survival was highly variable and generated most of the variability in population growth rates. At the surface, lack of variation explained by environmental covariates may suggest weak evidence of resource limitation in the population, when nutritional condition actually underpinned most demographics. We suggest that variability in vital rates and effects of resource limitation may depend on context more than previously appreciated, and density dependence can obfuscate the relationships between remotely sensed data and demographic rates.
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Morin A, Chamaillé-Jammes S, Valeix M. Climate Effects on Prey Vulnerability Modify Expectations of Predator Responses to Short- and Long-Term Climate Fluctuations. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2020.601202] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Climate changes affect the distribution and abundance of organisms, often via changes in species interactions. Most animals experience predation, and a number of models have investigated how climate fluctuations can influence predator–prey dynamics by affecting prey abundance through changes in resource availability. However, field studies have shown that prey vulnerability is a key feature determining the outcome of predator–prey interactions, which also varies with climatic conditions, via changes in prey body condition or in habitat characteristics (e.g. vegetation cover). In this theoretical work, we explore, with large mammals of African savannas in mind, how the interplay between climate-induced changes in prey abundance and climate-induced changes in prey vulnerability affects the immediate and long-term responses of predator populations. We account for prey body condition and habitat effects on prey vulnerability to predation. We show that predictions on how predator abundance responds to climate fluctuations differ depending on how climate influences prey vulnerability (habitat characteristics vs. prey body condition). We discuss how species traits influence the relative importance of the different sources of vulnerability. For example, our results suggest that populations of cursorial predators (such as spotted hyaenas) are expected to fare better than populations of ambush predators (such as African lions) in African ecosystems that will be characterised by an aridification. This study highlights the importance of understanding, and accounting for, the vulnerability factors associated to a given predator–prey pair, and improves our comprehension of predator–prey relationships in a changing climate.
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Watters F, Ramsey D, Molsher R, Cassey P. Breeding dynamics of overabundant koala (Phascolarctos cinereus) populations subject to fertility-control management. WILDLIFE RESEARCH 2021. [DOI: 10.1071/wr20162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract
ContextThe koala (Phascolarctos cinereus) sometimes occurs as an overabundant folivore in south-eastern Australia, where high-density populations have caused defoliation of preferred food trees, threatening habitat. Kangaroo Island, South Australia and Budj Bim National Park, Victoria, are two regions where such eruptive population dynamics have arisen. One way of mitigating their damage is through management via fertility control.
AimsThis paper examines the outcomes of fertility control (surgical sterilisation and treatment with levonorgestrel implants) on breeding dynamics at the population level, using data obtained from two separate koala management programs conducted by State Government wildlife agencies, South Australia Department for Environment and Water and Parks Victoria.
MethodsThe relationships between female body condition, reproductive status, fertility control, age and population density were examined using linear mixed effects models. Population density (koalas/ha) was estimated using annual census data and modelled in a Bayesian framework.
Key resultsBody condition was a key influence on breeding success in female koalas, with sexual maturity being defined by both age and body condition, whereas the effect of reproductive experience was minimal. It is likely that reduced densities have led to decreased intraspecific competition for food resources and territory, leading to increased breeding success at one management site (BBNP) and by allowing females to begin breeding at a lower overall body condition. The reduction in densities to sustainable levels at both management sites, despite differing fertility-control methods, supports the use of the less invasive and more cost-effective levonorgestrel implants as the preferred fertility-control method.
ConclusionsIn addition to contraceptive effects, broad-scale fertility control may have resulted in a compensatory higher breeding success in the untreated population, possibly in response to decreasing densities, increased resource availability or behavioural responses to population management.
ImplicationsAlthough compensatory breeding mechanisms can reduce the effectiveness of fertility control at the population level, ongoing fertility-control management can still be successful at reducing overabundant koala populations to sustainable levels with significant long-term commitment, provided that annual control targets are continuously met.
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Clark TJ, Horne JS, Hebblewhite M, Luis AD. Stochastic predation exposes prey to predator pits and local extinction. OIKOS 2020. [DOI: 10.1111/oik.07381] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- T. J. Clark
- Wildlife Biology Program, Dept of Ecosystem and Conservation Sciences, W. A. Franke College of Forestry and Conservation, Univ. of Montana Missoula MT USA
| | | | - Mark Hebblewhite
- Wildlife Biology Program, Dept of Ecosystem and Conservation Sciences, W. A. Franke College of Forestry and Conservation, Univ. of Montana Missoula MT USA
| | - Angela D. Luis
- Wildlife Biology Program, Dept of Ecosystem and Conservation Sciences, W. A. Franke College of Forestry and Conservation, Univ. of Montana Missoula MT USA
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Caillaud D, Eckardt W, Vecellio V, Ndagijimana F, Mucyo JP, Hirwa JP, Stoinski T. Violent encounters between social units hinder the growth of a high-density mountain gorilla population. SCIENCE ADVANCES 2020; 6:6/45/eaba0724. [PMID: 33148636 PMCID: PMC7673674 DOI: 10.1126/sciadv.aba0724] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 08/29/2020] [Indexed: 05/29/2023]
Abstract
Density-dependent processes such as competition for resources, migration, predation, and disease outbreaks limit the growth of natural populations. The analysis of 50 years of mountain gorilla data reveals that social behavior changes observed at high group density may also affect population growth in social species. A sudden increase in social group density observed in 2007 caused a threefold increase in the rate of violent encounters between social units (groups and solitary males). A fivefold increase in the rate of infanticide and seven cases of lethal fights among mature males were subsequently recorded, and the annual subpopulation growth rate declined by half between 2000 and 2017. The increase in infanticide alone explains 57% of this decline. These findings highlight the complex relationship between population density and growth in social species and hold important implications for the management of island populations.
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Affiliation(s)
- Damien Caillaud
- The Dian Fossey Gorilla Fund, 800 Cherokee Ave. SE, Atlanta, GA 30315, USA.
- Department of Anthropology, University of California, Davis, One Shields Ave., Davis, CA 95616, USA
| | - Winnie Eckardt
- The Dian Fossey Gorilla Fund, 800 Cherokee Ave. SE, Atlanta, GA 30315, USA
| | - Veronica Vecellio
- The Dian Fossey Gorilla Fund, 800 Cherokee Ave. SE, Atlanta, GA 30315, USA
| | - Felix Ndagijimana
- The Dian Fossey Gorilla Fund, 800 Cherokee Ave. SE, Atlanta, GA 30315, USA
| | - Jean-Pierre Mucyo
- The Dian Fossey Gorilla Fund, 800 Cherokee Ave. SE, Atlanta, GA 30315, USA
| | - Jean-Paul Hirwa
- The Dian Fossey Gorilla Fund, 800 Cherokee Ave. SE, Atlanta, GA 30315, USA
| | - Tara Stoinski
- The Dian Fossey Gorilla Fund, 800 Cherokee Ave. SE, Atlanta, GA 30315, USA.
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