1
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Britnell JA, Kerley GIH, Antwis R, Shultz S. A grazer's niche edge is associated with increasing diet diversity and poor population performance. Ecol Lett 2024; 27:e14357. [PMID: 38193626 DOI: 10.1111/ele.14357] [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: 07/25/2023] [Revised: 11/09/2023] [Accepted: 12/05/2023] [Indexed: 01/10/2024]
Abstract
The core-periphery hypothesis predicts niche cores should be associated with greater survivorship, reproductive output and population performance rates than marginal habitats at niche edges. However, there is very little empirical evidence of whether niche centrality influences population trends in animals. Using the Cape mountain zebra (Equus zebra zebra) as a model system, we evaluated whether niche centrality is associated with population trends, resource availability and diet across a core-periphery gradient. Population growth rates and density progressively declined towards niche peripheries. Niche peripheries were resource-poor and Cape mountain zebra consumed more phylogenetically diverse diets dominated by non-grass families. In core habitats they consumed grass-rich diets and female reproductive success was higher. This combination of spatial niche modelling and functional ecology provides a novel evaluation of how bottom-up resource limitation can shape species distributions, population resilience and range change and can guide conservation management.
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Affiliation(s)
- J A Britnell
- School of Earth and Environmental Sciences, University of Manchester, Manchester, UK
- North of England Zoological Society (Chester Zoo), Upton-by-Chester, UK
| | - G I H Kerley
- Centre for African Conservation Ecology, Nelson Mandela University, Gqeberha, South Africa
| | | | - S Shultz
- School of Earth and Environmental Sciences, University of Manchester, Manchester, UK
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2
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Passoni G, Coulson T, Cagnacci F, Hudson P, Stahler DR, Smith DW, Lachish S. Investigating tritrophic interactions using bioenergetic demographic models. Ecology 2024; 105:e4197. [PMID: 37897692 DOI: 10.1002/ecy.4197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 07/27/2023] [Accepted: 09/18/2023] [Indexed: 10/30/2023]
Abstract
A central debate in ecology has been the long-running discussion on the role of apex predators in affecting the abundance and dynamics of their prey. In terrestrial systems, research has primarily relied on correlational approaches, due to the challenge of implementing robust experiments with replication and appropriate controls. A consequence of this is that we largely suffer from a lack of mechanistic understanding of the population dynamics of interacting species, which can be surprisingly complex. Mechanistic models offer an opportunity to examine the causes and consequences of some of this complexity. We present a bioenergetic mechanistic model of a tritrophic system where the primary vegetation resource follows a seasonal growth function, and the herbivore and carnivore species are modeled using two integral projection models (IPMs) with body mass as the phenotypic trait. Within each IPM, the demographic functions are structured according to bioenergetic principles, describing how animals acquire and transform resources into body mass, energy reserves, and breeding potential. We parameterize this model to reproduce the population dynamics of grass, elk, and wolves in northern Yellowstone National Park (USA) and investigate the impact of wolf reintroduction on the system. Our model generated predictions that closely matched the observed population sizes of elk and wolf in Yellowstone prior to and following wolf reintroduction. The introduction of wolves into our basal grass-elk bioenergetic model resulted in a population of 99 wolves and a reduction in elk numbers by 61% (from 14,948 to 5823) at equilibrium. In turn, vegetation biomass increased by approximately 25% in the growing season and more than threefold in the nongrowing season. The addition of wolves to the model caused the elk population to switch from being food-limited to being predator-limited and had a stabilizing effect on elk numbers across different years. Wolf predation also led to a shift in the phenotypic composition of the elk population via a small increase in elk average body mass. Our model represents a novel approach to the study of predator-prey interactions, and demonstrates that explicitly considering and linking bioenergetics, population demography and body mass phenotypes can provide novel insights into the mechanisms behind complex ecosystem processes.
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Affiliation(s)
- Gioele Passoni
- Department of Biology, University of Oxford, Oxford, UK
- Animal Ecology Unit, Research and Innovation Centre (CRI), Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Tim Coulson
- Department of Biology, University of Oxford, Oxford, UK
| | - Francesca Cagnacci
- Animal Ecology Unit, Research and Innovation Centre (CRI), Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Peter Hudson
- The Huck Institutes, Penn State University, State College, Pennsylvania, USA
| | - Daniel R Stahler
- Yellowstone Center for Resources, Yellowstone National Park, Wyoming, USA
| | - Douglas W Smith
- Yellowstone Center for Resources, Yellowstone National Park, Wyoming, USA
| | - Shelly Lachish
- Commonwealth Scientific Industrial Research Organisation (CSIRO) Environment Unit, Dutton Park, Queensland, Australia
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3
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Vandergast AG, Brehme CS, Iwanowicz D, Cornman RS, Adsit‐Morris D, Fisher RN. Fecal metabarcoding of the endangered Pacific pocket mouse ( Perognathus longimembris pacificus) reveals a diverse and forb rich diet that reflects local habitat availability. Ecol Evol 2023; 13:e10460. [PMID: 37745784 PMCID: PMC10514273 DOI: 10.1002/ece3.10460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/02/2023] [Accepted: 08/17/2023] [Indexed: 09/26/2023] Open
Abstract
Information on diet breadth and preference can assist in understanding links between food resources and population growth and inform habitat restoration for rare herbivores. We assessed the diet of the endangered Pacific pocket mouse using metabarcoding of fecal samples and compared it to plant community composition in long-term study plots in two populations on Marine Corps Base Camp Pendleton, San Diego County, CA. Fecal samples (n = 221) were collected between spring 2016 and fall 2017 during monthly live-trap surveys. Concurrently, percent cover and plant phenology were measured in plots centered on trap locations. Fecal samples were sequenced with paired-end reads of the internal transcribed spacer 2 region of the nuclear ribosomal gene, and the resulting amplicons were matched to a regionally specific database. Seventy-three plant taxa were detected, which were mostly forbs and perennial herbs (70-90%). Diet composition differed between populations, years, seasons, and plots. Overall, diet and local habitat composition in plots were significantly correlated. However, we detected some differences in above-ground seed availability and proportion in fecal samples that indicate diet preferences for some forbs, perennial herbs, and native bunch grasses over perennial shrubs and non-native grasses. This is the first study of PPM to pair plant phenology surveys with diet metabarcoding to estimate resource selection, and results suggest that managing habitat for diverse native forb communities and reducing non-native grass cover may be beneficial for this critically endangered species.
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Affiliation(s)
- Amy G. Vandergast
- U.S. Geological SurveyWestern Ecological Research CenterSan DiegoCaliforniaUSA
| | - Cheryl S. Brehme
- U.S. Geological SurveyWestern Ecological Research CenterSan DiegoCaliforniaUSA
| | - Deborah Iwanowicz
- U.S. Geological Survey, Eastern Ecological Science Center, Leetown Research LaboratoryKearneysvilleWest VirginiaUSA
| | - Robert S. Cornman
- U.S. Geological SurveyFort Collins Science CenterFort CollinsColoradoUSA
| | - Devin Adsit‐Morris
- U.S. Geological SurveyWestern Ecological Research CenterSan DiegoCaliforniaUSA
| | - Robert N. Fisher
- U.S. Geological SurveyWestern Ecological Research CenterSan DiegoCaliforniaUSA
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4
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Murphy KJ, Roberts DR, Jensen WF, Nielsen SE, Johnson SK, Hosek BM, Stillings B, Kolar J, Boyce MS, Ciuti S. Mule deer fawn recruitment dynamics in an energy disturbed landscape. Ecol Evol 2023; 13:e9976. [PMID: 37091564 PMCID: PMC10116077 DOI: 10.1002/ece3.9976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 01/30/2023] [Accepted: 03/17/2023] [Indexed: 04/25/2023] Open
Abstract
Wildlife population dynamics are modulated by abiotic and biotic factors, typically climate, resource availability, density-dependent effects, and predator-prey interactions. Understanding whether and how human-caused disturbances shape these ecological processes is helpful for the conservation and management of wildlife and their habitats within increasingly human-dominated landscapes. However, many jurisdictions lack either long-term longitudinal data on wildlife populations or measures of the interplay between human-mediated disturbance, climate, and predator density. Here, we use a 50-year time series (1962-2012) on mule deer (Odocoileus hemionus) demographics, seasonal weather, predator density, and oil and gas development patterns from the North Dakota Badlands, USA, to investigate long-term effects of landscape-level disturbance on mule deer fawn fall recruitment, which has declined precipitously over the last number of decades. Mule deer fawn fall recruitment in this study represents the number of fawns per female (fawn:female ratio) that survive through the summer to October. We used this fawn recruitment index to evaluate the composite effects of interannual extreme weather conditions, energy development, and predator density. We found that density-dependent effects and harsh seasonal weather were the main drivers of fawn fall recruitment in the North Dakota Badlands. These effects were further shaped by the interaction between harsh seasonal weather and predator density (i.e., lower fawn fall recruitment when harsh weather was combined with higher predator density). Additionally, we found that fawn fall recruitment was modulated by interactions between seasonal weather and energy development (i.e., lower fawn fall recruitment when harsh weather was combined with higher density of active oil and gas wells). Interestingly, we found that the combined effect of predator density and energy development was not interactive but rather additive. Our analysis demonstrates how energy development may modulate fluctuations in mule deer fawn fall recruitment concurrent with biotic (density-dependency, habitat, predation, woody vegetation encroachment) and abiotic (harsh seasonal weather) drivers. Density-dependent patterns emerge, presumably due to limited quality habitat, being the primary factor influencing fall fawn recruitment in mule deer. Secondarily, stochastic weather events periodically cause dramatic declines in recruitment. And finally, the additive effects of human disturbance and predation can induce fluctuations in fawn fall recruitment. Here we make the case for using long-term datasets for setting long-term wildlife management goals that decision makers and the public can understand and support.
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Affiliation(s)
- Kilian J. Murphy
- Laboratory of Wildlife Ecology and Behaviour, School of Biology and Environmental ScienceUniversity College DublinDublinIreland
| | - David R. Roberts
- Ministry of Environment and Parks, Government of Alberta3535 Research Road NWCalgaryAlbertaT2L 2K8Canada
- InnoTech Alberta3608 33 Street NWCalgaryAlbertaT2 L 2A6Canada
| | | | - Scott E. Nielsen
- Department of Renewable ResourcesUniversity of AlbertaEdmontonAlbertaCanada
| | | | - Brian M. Hosek
- North Dakota Game and Fish DepartmentBismarckNorth Dakota58501USA
| | - Bruce Stillings
- North Dakota Game and Fish DepartmentDickinsonNorth Dakota58601USA
| | - Jesse Kolar
- North Dakota Game and Fish DepartmentDickinsonNorth Dakota58601USA
| | - Mark S. Boyce
- Department of Biological SciencesUniversity of AlbertaEdmontonAlbertaCanada
| | - Simone Ciuti
- Laboratory of Wildlife Ecology and Behaviour, School of Biology and Environmental ScienceUniversity College DublinDublinIreland
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Silber KM, Mohankumar NM, Hefley TJ, Boyle WA. Emigration and survival correlate with different precipitation metrics throughout a grassland songbird's annual cycle. J Wildl Manage 2023. [DOI: 10.1002/jwmg.22371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- Katy M. Silber
- Kansas State University, Division of Biology Manhattan KS 66506 USA
| | | | - Trevor J. Hefley
- Kansas State University, Department of Statistics Manhattan KS 66506 USA
| | - W. Alice Boyle
- Kansas State University, Division of Biology Manhattan KS 66506 USA
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6
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Landscape drivers of site occupancy by remnant populations of arctic ground squirrels (Urocitellus parryii). EUR J WILDLIFE RES 2021. [DOI: 10.1007/s10344-021-01534-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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7
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Johnson HE, Golden TS, Adams LG, Gustine DD, Lenart EA, Barboza PS. Dynamic selection for forage quality and quantity in response to phenology and insects in an Arctic ungulate. Ecol Evol 2021; 11:11664-11688. [PMID: 34522332 PMCID: PMC8427565 DOI: 10.1002/ece3.7852] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 06/03/2021] [Accepted: 06/07/2021] [Indexed: 12/04/2022] Open
Abstract
Spatiotemporal variation in forage is a primary driver of ungulate behavior, yet little is known about the nutritional components they select, and how selection varies across the growing season with changes in forage quality and quantity. We addressed these uncertainties in barren-ground caribou (Rangifer tarandus), which experience their most important foraging opportunities during the short Arctic summer. Recent declines in Arctic caribou populations have raised concerns about the influence of climate change on summer foraging opportunities, given shifting vegetation conditions and insect harassment, and their potential effects on caribou body condition and demography. We examined Arctic caribou selection of summer forage by pairing locations from females in the Central Arctic Herd of Alaska with spatiotemporal predictions of biomass, digestible nitrogen (DN), and digestible energy (DE). We then assessed selection for these nutritional components across the growing season at landscape and patch scales, and determined whether foraging opportunities were constrained by insect harassment. During early summer, at the landscape scale, caribou selected for intermediate biomass and high DN and DE, following expectations of the forage maturation hypothesis. At the patch scale, however, caribou selected for high values of all forage components, particularly DN, suggesting that protein may be limiting. During late summer, after DN declined below the threshold for protein gain, caribou exhibited a switch at both spatial scales, selecting for higher biomass, likely enabling mass and fat deposition. Mosquito activity strongly altered caribou selection of forage and increased their movement rates, while oestrid fly activity had little influence. Our results demonstrate that early and late summer periods afford Arctic caribou distinct foraging opportunities, as they prioritize quality earlier in the summer and quantity later. Climate change may further constrain caribou access to DN as earlier, warmer Arctic summers may be associated with reduced DN and increased mosquito harassment.
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Affiliation(s)
| | - Trevor S. Golden
- Alaska Science CenterU.S. Geological SurveyAnchorageAlaska
- Present address:
Axiom Data Science1016 West 6th AvenueAnchorageAlaska99501
| | - Layne G. Adams
- Alaska Science CenterU.S. Geological SurveyAnchorageAlaska
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8
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Lavergne SG, Krebs CJ, Kenney AJ, Boutin S, Murray D, Palme R, Boonstra R. The impact of variable predation risk on stress in snowshoe hares over the cycle in North America's boreal forest: adjusting to change. Oecologia 2021; 197:71-88. [PMID: 34435235 DOI: 10.1007/s00442-021-05019-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 08/16/2021] [Indexed: 11/26/2022]
Abstract
The boreal forest is one of the world's ecosystems most affected by global climate warming. The snowshoe hare, its predators, and their population dynamics dominate the mammalian component of the North American boreal forest. Our past research has shown the 9-11-year hare cycle to be predator driven, both directly as virtually all hares that die are killed by their predators, and indirectly through sublethal risk effects on hare stress physiology, behavior, and reproduction. We replicated this research over the entire cycle by measuring changes in predation risk expected to drive changes in chronic stress. We examined changes in hare condition and stress axis function using a hormonal challenge protocol in the late winter of 7 years-spanning all phases of the cycle from the increase through to the low (2014-2020). We simultaneously monitored changes in hare abundance as well as those of their primary predators, lynx and coyotes. Despite observing the expected changes in hare-predator numbers over the cycle, we did not see the predicted changes in chronic stress metrics in the peak and decline phases. Thus, the comprehensive physiological signature indicative of chronic predator-induced stress seen from our previous work was not present in this current cycle. We postulate that hares may now be increasingly showing behavior-mediated rather than stress-mediated responses to their predators. We present evidence that increases in primary productivity have affected boreal community structure and function. We speculate that climate change has caused this major shift in the indirect effects of predation on hares.
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Affiliation(s)
- Sophia G Lavergne
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada
| | - Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Alice J Kenney
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Stan Boutin
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Dennis Murray
- Department of Biology, Trent University, Peterborough, ON, Canada
| | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto Scarborough, Toronto, ON, Canada.
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Tobajas J, Descalzo E, Ferreras P, Mateo R, Margalida A. Effects on carrion consumption in a mammalian scavenger community when dominant species are excluded. Mamm Biol 2021. [DOI: 10.1007/s42991-021-00163-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AbstractCarrion is a valuable resource exploited not only by obligate scavengers but also by a wide variety of facultative scavengers. These species provide several important ecosystem services which can suffer if the scavenger community composition is altered, thus reducing the ecosystem provided. We studied the response of the Mediterranean facultative scavenger community to the exclusion of larger scavenger species (red fox Vulpes vulpes, European badger Meles meles, and wild boar Sus scrofa) using an exclusion fence permeable to small scavenger species (mainly Egyptian mongoose Herpestes ichneumon, common genet Genetta genetta, and stone marten Martes foina). The exclusion of dominant facultative scavengers led to a significant reduction in the amount of carrion consumed and an increase in carrion available for smaller species and decomposers, over a longer period of time. Although carrion consumption by the non-excluded species increased inside the exclusion area relative to the control area, it was insufficient to compensate for the carrion not eaten by the dominant scavengers. Of the small scavenger species, only the Egyptian mongoose significantly increased its carrion consumption in the exclusion area, and was the main beneficiary of the exclusion of dominant facultative scavengers. Therefore, altering the facultative scavenger community in Mediterranean woodlands can reduce the efficiency of small carcass removal and benefit other opportunistic species, such as the Egyptian mongoose, by increasing the carrion available to them. This interaction could have substantial implications for disease transmission, nutrient cycling, and ecosystem function.
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Abstract
Moths (Lepidoptera) are major agricultural and forest pests in many parts of the world, including Europe, with many causing great economic damage to crops, horticultural plants, stored items, and wool products. Here, we focus on two ecologically similar inchworms, Operophtera brumata and Erannis defoliaria, known for their high foliage consumption during the spring emergence of caterpillars. We hypothesise that bats could play a role in reducing pests such as caterpillars by switching to this abundant emerging prey. At two infested and one control forest sites, caterpillars were sampled during spring to determine levels of infestation. At the same time, bat flight activity was monitored during the peak in caterpillar abundance. During the spring caterpillar outbreak, we collected faecal samples of forest-dwelling bats capable of using gleaning. The majority of samples were positive for our focus species, being 51.85% for O. brumata and 29.63% for E. defoliaria faecal samples. The foraging activity of two gleaning bats, Myotis nattereri and Myotis bechsteinii, increased at both infested sites, but not at the control site, during caterpillar emergence, as did foraging of Plecotus auritus/austriacus, which used both gleaning and aerial hawking. We conclude that both specialists and occasional gleaners, which prefer different prey but are able to switch their foraging strategies, aggregate at sites during pest emergence and, as such, our results confirm the high potential of bats to reduce numbers of pest species such as caterpillars.
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11
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Costán A, Sarasola JH. Raptors, doves and fragmented landscapes: Overabundance of native birds elicit numerical and functional responses of avian top predators. FOOD WEBS 2021. [DOI: 10.1016/j.fooweb.2020.e00184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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Abstract
The effects of human disturbance spread over virtually all ecosystems and ecological communities on Earth. In this review, we focus on the effects of human disturbance on terrestrial apex predators. We summarize their ecological role in nature and how they respond to different sources of human disturbance. Apex predators control their prey and smaller predators numerically and via behavioral changes to avoid predation risk, which in turn can affect lower trophic levels. Crucially, reducing population numbers and triggering behavioral responses are also the effects that human disturbance causes to apex predators, which may in turn influence their ecological role. Some populations continue to be at the brink of extinction, but others are partially recovering former ranges, via natural recolonization and through reintroductions. Carnivore recovery is both good news for conservation and a challenge for management, particularly when recovery occurs in human-dominated landscapes. Therefore, we conclude by discussing several management considerations that, adapted to local contexts, may favor the recovery of apex predator populations and their ecological functions in nature.
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13
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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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14
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Gutiérrez R, Córdova-Lepe F, Moreno-Gómez FN, Velásquez NA. Persistence and size of seasonal populations on a consumer-resource relationship depends on the allocation strategy toward life-history functions. Sci Rep 2020; 10:21401. [PMID: 33293662 PMCID: PMC7722923 DOI: 10.1038/s41598-020-77326-1] [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: 07/17/2020] [Accepted: 10/27/2020] [Indexed: 11/09/2022] Open
Abstract
The long-term ecological dynamics of a population inhabiting a seasonal environment is analyzed using a semi-discrete or impulsive system to represent the consumer-resource interaction. The resource corresponds to an incoming energy flow for consumers that is allocated to reproduction as well as to maintenance in each non-reproductive season. The energy invested in these life-history functions is used in reproductive events, determining the size of the offspring in each reproductive season. Two long-term dynamic patterns are found, resulting in either the persistence or the extinction of the population of consumers. In addition, our model indicates that only one energy allocation strategy provides an optimal combination between individual consumption and long-term population size. The current study contributes to the understanding of how the individual-level and the population-level are interrelated, exhibiting the importance of incorporating phenotypic traits in population dynamics.
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Affiliation(s)
- Rodrigo Gutiérrez
- Doctorado en Modelamiento Matemático Aplicado, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile. .,Laboratorio de Comunicación Animal, Departamento de Biología y Química, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile. .,Facultad de Ciencias Básicas, Departamento de Matemática, Física y Estadística, Universidad Católica del Maule, Talca, Chile.
| | - Fernando Córdova-Lepe
- Doctorado en Modelamiento Matemático Aplicado, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile.,Facultad de Ciencias Básicas, Departamento de Matemática, Física y Estadística, Universidad Católica del Maule, Talca, Chile
| | - Felipe N Moreno-Gómez
- Doctorado en Modelamiento Matemático Aplicado, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile.,Laboratorio de Bioacústica y Ecología del Comportamiento Animal, Departamento de Biología y Química, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile
| | - Nelson A Velásquez
- Doctorado en Modelamiento Matemático Aplicado, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile.,Laboratorio de Comunicación Animal, Departamento de Biología y Química, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile
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15
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Peters RM, Cherry MJ, Kilgo JC, Chamberlain MJ, Miller KV. White‐Tailed Deer Population Dynamics Following Louisiana Black Bear Recovery. J Wildl Manage 2020. [DOI: 10.1002/jwmg.21947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Rebecca M. Peters
- Daniel B. Warnell School of Forestry and Natural Resources University of Georgia Athens GA 30602 USA
| | - Michael J. Cherry
- Caesar Kleberg Wildlife Research Institute, Texas A&M University—Kingsville Kingsville TX 78363 USA
| | - John C. Kilgo
- USDA Forest Service, Southern Research Station P.O. Box 700 New Ellenton SC 29809 USA
| | - Michael J. Chamberlain
- Daniel B. Warnell School of Forestry and Natural Resources University of Georgia Athens GA 30602 USA
| | - Karl V. Miller
- Daniel B. Warnell School of Forestry and Natural Resources University of Georgia Athens GA 30602 USA
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16
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Balisi MA, Van Valkenburgh B. Iterative evolution of large-bodied hypercarnivory in canids benefits species but not clades. Commun Biol 2020; 3:461. [PMID: 32826954 PMCID: PMC7442796 DOI: 10.1038/s42003-020-01193-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 07/30/2020] [Indexed: 11/08/2022] Open
Abstract
Ecological specialization has costs and benefits at various scales: traits benefitting an individual may disadvantage its population, species or clade. In particular, large body size and hypercarnivory (diet over 70% meat) have evolved repeatedly in mammals; yet large hypercarnivores are thought to be trapped in a macroevolutionary "ratchet", marching unilaterally toward decline. Here, we weigh the impact of this specialization on extinction risk using the rich fossil record of North American canids (dogs). In two of three canid subfamilies over the past 40 million years, diversification of large-bodied hypercarnivores appears constrained at the clade level, biasing specialized lineages to extinction. However, despite shorter species durations, extinction rates of large hypercarnivores have been mostly similar to those of all other canids. Extinction was size- and carnivory-selective only at the end of the Pleistocene epoch 11,000 years ago, suggesting that large hypercarnivores were not disadvantaged at the species level before anthropogenic influence.
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Affiliation(s)
- Mairin A Balisi
- La Brea Tar Pits and Museum, Los Angeles, CA, 90036, USA.
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, 90095, USA.
- Department of Vertebrate Paleontology, Natural History Museum of Los Angeles County, Los Angeles, CA, 90007, USA.
- Department of Life and Environmental Sciences, University of California, Merced, CA, 95343, USA.
| | - Blaire Van Valkenburgh
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, 90095, USA
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17
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Cummings CR, Hernandez SM, Murray M, Ellison T, Adams HC, Cooper RE, Curry S, Navara KJ. Effects of an anthropogenic diet on indicators of physiological challenge and immunity of white ibis nestlings raised in captivity. Ecol Evol 2020; 10:8416-8428. [PMID: 32788990 PMCID: PMC7417218 DOI: 10.1002/ece3.6548] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 05/12/2020] [Accepted: 06/02/2020] [Indexed: 12/01/2022] Open
Abstract
When wildlife forage and/or live in urban habitats, they often experience a shift in resource availability and dietary quality. Some species even use human handouts, such as bread, as well as human refuse, as a large part of their new diets; yet the influences of this nutritional shift on health and survival remain unclear. American white ibises are increasingly being seen in urban areas in Florida; they collect handouts, such as bread and other food items, from humans in parks, and are also found foraging on anthropogenic sources in trash heaps. We hypothesized that the consumption of these new anthropogenic food sources may trigger increases in indicators of physiological challenge and dampen immune responses. We tested this experimentally by raising 20 white ibis nestlings in captivity, and exposing 10 to a simulated anthropogenic diet (including the addition of white bread and a reduction in seafood content) while maintaining 10 on a diet similar to what ibises consume in more natural environments. We then tested two indicators of physiological challenge (corticosterone and heat shock protein 70), assessed innate immunity in these birds via bactericidal assays and an in vitro carbon clearance assay, and adaptive immunity using a phytohemagglutinin skin test. The anthropogenic diet depressed the development of the ability to kill Salmonella paratyphi in culture. Our results suggest that consuming an anthropogenic diet may be detrimental in terms of the ability to battle a pathogenic bacterial species, but there was little effect on indicators of physiological challenge and other immunological measures.
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Affiliation(s)
| | - Sonia M. Hernandez
- Warnell School of Forestry and Natural ResourcesThe University of GeorgiaAthensGAUSA
| | - Maureen Murray
- Department of Poultry ScienceThe University of GeorgiaAthensGAUSA
- Warnell School of Forestry and Natural ResourcesThe University of GeorgiaAthensGAUSA
| | - Taylor Ellison
- Department of Poultry ScienceThe University of GeorgiaAthensGAUSA
- Warnell School of Forestry and Natural ResourcesThe University of GeorgiaAthensGAUSA
| | - Henry C. Adams
- Department of Poultry ScienceThe University of GeorgiaAthensGAUSA
- Warnell School of Forestry and Natural ResourcesThe University of GeorgiaAthensGAUSA
| | - Robert E. Cooper
- Department of Poultry ScienceThe University of GeorgiaAthensGAUSA
- Warnell School of Forestry and Natural ResourcesThe University of GeorgiaAthensGAUSA
| | - Shannon Curry
- Warnell School of Forestry and Natural ResourcesThe University of GeorgiaAthensGAUSA
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18
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Hagen R, Suchant R. Evidence of a spatial auto-correlation in the browsing level of four major European tree species. Ecol Evol 2020; 10:8517-8527. [PMID: 32788997 PMCID: PMC7417255 DOI: 10.1002/ece3.6577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 11/16/2022] Open
Abstract
The contribution of spatial processes to the spatial patterns of ecological systems is widely recognized, but spatial patterns in the ecology of plant-herbivore interactions have rarely been investigated quantitatively owing to limited budget and time associated with ecological research. Studies of the level of browsing on various tree species reported either no spatial auto-correlation or a small effect size. Further, the effects of disturbance events, such as hurricanes, which create large forest openings on spatial patterns of herbivory are not well understood.In this study, we used forest inventory data obtained from the federal state of Baden-Württemberg (Southern Germany) between 2001 and 2009 (grid size: 100 × 200 m) and thus, after hurricane Lothar struck Southern Germany in 1999. We investigated whether the browsing level of trees (height ≤ 130 cm) in one location is independent of that of the neighborhood.Our analyses of 1,758,622 saplings (187.632 sampling units) of oak (Quercus), fir (Abies), spruce (Picea), and beech (Fagus) revealed that the browsing level is characterized by a short distance spatial auto-correlation.The application of indicator variables based on browsed saplings should account for the spatial pattern as the latter may affect the results and therefore also the conclusions of the analysis.
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Affiliation(s)
- Robert Hagen
- Forest Research Institute of Baden‐Württemberg (FVA)FreiburgGermany
- Leibniz Institute for Zoo and Wildlife ResearchBerlinGermany
| | - Rudi Suchant
- Forest Research Institute of Baden‐Württemberg (FVA)FreiburgGermany
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19
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Soledade Lemos L, Burnett JD, Chandler TE, Sumich JL, Torres LG. Intra‐ and inter‐annual variation in gray whale body condition on a foraging ground. Ecosphere 2020. [DOI: 10.1002/ecs2.3094] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Leila Soledade Lemos
- Geospatial Ecology of Marine Megafauna Lab Marine Mammal Institute, Fisheries and Wildlife Department Oregon State University Corvallis Oregon 97331 USA
| | - Jonathan D. Burnett
- Aerial Information Systems Laboratory Forest Engineering, Resources and Management Department Oregon State University Corvallis Oregon 97331 USA
| | - Todd E. Chandler
- Geospatial Ecology of Marine Megafauna Lab Marine Mammal Institute, Fisheries and Wildlife Department Oregon State University Corvallis Oregon 97331 USA
| | - James L. Sumich
- Fisheries and Wildlife Department Oregon State University Corvallis Oregon 97331 USA
| | - Leigh G. Torres
- Geospatial Ecology of Marine Megafauna Lab Marine Mammal Institute, Fisheries and Wildlife Department Oregon State University Corvallis Oregon 97331 USA
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20
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Geary WL, Hradsky BA, Robley A, Wintle BA. Predators, fire or resources: What drives the distribution of herbivores in fragmented mesic forests? AUSTRAL ECOL 2020. [DOI: 10.1111/aec.12861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- William L. Geary
- Quantitative and Applied Ecology Group School of BioSciences University of Melbourne Parkville Melbourne Victoria 3010 Australia
- Biodiversity Division Department of Environment, Land, Water & Planning East Melbourne Victoria Australia
- Centre for Integrative Ecology School of Life and Environmental Sciences (Burwood Campus) Deakin University Geelong Victoria Australia
| | - Bronwyn A. Hradsky
- Quantitative and Applied Ecology Group School of BioSciences University of Melbourne Parkville Melbourne Victoria 3010 Australia
| | - Alan Robley
- Department of Environment, Land, Water and Planning Arthur Rylah Institute for Environmental Research Heidelberg Victoria Australia
| | - Brendan A. Wintle
- Quantitative and Applied Ecology Group School of BioSciences University of Melbourne Parkville Melbourne Victoria 3010 Australia
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21
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Proctor MF, McLellan BN, Stenhouse GB, Mowat G, Lamb CT, Boyce MS. Effects of roads and motorized human access on grizzly bear populations in British Columbia and Alberta, Canada. URSUS 2020. [DOI: 10.2192/ursus-d-18-00016.2] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Michael F. Proctor
- Birchdale Ecological, P.O. Box 606, Kaslo, British Columbia, V0G 1M0, Canada
| | - Bruce N. McLellan
- Ministry of Forest, Lands, & Natural Resource Operations, P.O. Box 1732, D'Arcy, British Columbia, V0N 1L0, Canada
| | | | - Garth Mowat
- Ministry of Forest, Lands, Natural Resource Operations & Rural Development, Nelson, British Columbia, V1L 4K3, Canada
| | - Clayton T. Lamb
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada
| | - Mark S. Boyce
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada
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22
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Castilla AR, Garrote PJ, Żywiec M, Calvo G, Suárez-Esteban A, Delibes M, Godoy JA, Picó FX, Fedriani JM. Genetic rescue by distant trees mitigates qualitative pollen limitation imposed by fine-scale spatial genetic structure. Mol Ecol 2019; 28:4363-4374. [PMID: 31495974 DOI: 10.1111/mec.15233] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 07/17/2019] [Accepted: 07/22/2019] [Indexed: 11/26/2022]
Abstract
Restricted seed dispersal frequently leads to fine-scale spatial genetic structure (i.e., FSGS) within plant populations. Depending on its spatial extent and the mobility of pollinators, this inflated kinship at the immediate neighbourhood can critically impoverish pollen quality. Despite the common occurrence of positive FSGS within plant populations, our knowledge regarding the role of long-distance pollination preventing reproductive failure is still limited. Using microsatellite markers, we examined the existence of positive FSGS in two low-density populations of the tree Pyrus bourgaeana. We also designed controlled crosses among trees differing in their kinship to investigate the effects of increased local kinship on plant reproduction. We used six pollination treatments and fully monitored fruit production, fruit and seed weight, proportion of mature seeds per fruit, and seed germination. Our results revealed positive FSGS in both study populations and lower fruit initiation in flowers pollinated with pollen from highly-genetically related individuals within the neighbourhood, with this trend intensifying as the fruit development progressed. Besides, open-pollinated flowers exhibited lower performance compared to those pollinated by distant pollen donors, suggesting intense qualitative pollen limitation in natural populations. We found positive fine-scale spatial genetic structure is translated into impoverished pollen quality from nearby pollen donors which negatively impacts the reproductive success of trees in low-density populations. Under this scenario of intrapopulation genetic rescue by distant pollen donors, the relevance of highly-mobile pollinators for connecting spatially and genetically distant patches of trees may be crucial to safeguarding population recruitment.
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Affiliation(s)
- Antonio R Castilla
- Instituto Superior of Agronomy, Centre for Applied Ecology "Prof. Baeta Neves"/INBIO, University of Lisbon, Lisbon, Portugal.,Departamento de Ecología Integrativa, Estación Biológica de Doñana (EBD), Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - Pedro J Garrote
- Instituto Superior of Agronomy, Centre for Applied Ecology "Prof. Baeta Neves"/INBIO, University of Lisbon, Lisbon, Portugal.,Departamento de Biología de la Conservación, Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - Magdalena Żywiec
- Instituto Superior of Agronomy, Centre for Applied Ecology "Prof. Baeta Neves"/INBIO, University of Lisbon, Lisbon, Portugal.,W. Szafer Institute of Botany, Polish Academy of Sciences, Krakow, Poland
| | - Gemma Calvo
- Departamento de Biología de la Conservación, Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - Alberto Suárez-Esteban
- Departamento de Biología de la Conservación, Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - Miguel Delibes
- Departamento de Biología de la Conservación, Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - José A Godoy
- Departamento de Ecología Integrativa, Estación Biológica de Doñana (EBD), Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - F Xavier Picó
- Departamento de Ecología Integrativa, Estación Biológica de Doñana (EBD), Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - Jose M Fedriani
- Instituto Superior of Agronomy, Centre for Applied Ecology "Prof. Baeta Neves"/INBIO, University of Lisbon, Lisbon, Portugal.,Departamento de Biología de la Conservación, Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain.,Centro de Investigaciones sobre Desertificación CIDE, CSIC-UVEG-GV, Moncada, Spain
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23
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Gigliotti LC, Slotow R, Hunter LTB, Fattebert J, Sholto-Douglas C, Jachowski DS. Context dependency of top-down, bottom-up and density-dependent influences on cheetah demography. J Anim Ecol 2019; 89:449-459. [PMID: 31469173 DOI: 10.1111/1365-2656.13099] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/12/2019] [Indexed: 11/30/2022]
Abstract
Research on drivers of demographic rates has mostly focused on top predators and their prey, and comparatively less research has considered the drivers of mesopredator demography. Of those limited studies, most focused on top-down effects of apex predators on mesopredator population dynamics, whereas studies investigating alternative mechanisms are less common. In this study, we tested hypotheses related to top-down, bottom-up and density-dependent regulation of demographic rates in an imperilled mesopredator, the cheetah (Acinonyx jubatus). We used a 25-year dataset of lion density, cheetah density and prey density from the Mun-Ya-Wana Conservancy in South Africa and assessed the effects of top-down, bottom-up and density-dependent drivers on cheetah survival and reproduction. In contrast to the top-down and bottom-up predictions, both adult and juvenile cheetahs experienced the lowest survival during months with high prey densities and low lion densities. We observed support only for a density-dependent response in juvenile cheetahs, where they had a higher probability of reaching independence during times with low cheetah density and low prey density. We did not identify any strong drivers of litter size. Collectively, our results indicate that high apex predator abundance might not always have negative effects on mesopredator populations, and suggest that context dependency in top-down, bottom-up and density-dependent factors may regulate demographic rates of cheetahs and other mesopredators. Our results highlight the complexities of population-level drivers of cheetah demographic rates and the importance of considering multiple hypotheses of mesopredator population regulation.
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Affiliation(s)
- Laura C Gigliotti
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC, USA
| | - Rob Slotow
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Luke T B Hunter
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa.,Wildlife Conservation Society, New York, NY, USA
| | - Julien Fattebert
- School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa.,Panthera, New York, NY, USA.,Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, WY, USA
| | | | - David S Jachowski
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC, USA
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24
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Kelt DA, Heske EJ, Lambin X, Oli MK, Orrock JL, Ozgul A, Pauli JN, Prugh LR, Sollmann R, Sommer S. Advances in population ecology and species interactions in mammals. J Mammal 2019. [DOI: 10.1093/jmammal/gyz017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
AbstractThe study of mammals has promoted the development and testing of many ideas in contemporary ecology. Here we address recent developments in foraging and habitat selection, source–sink dynamics, competition (both within and between species), population cycles, predation (including apparent competition), mutualism, and biological invasions. Because mammals are appealing to the public, ecological insight gleaned from the study of mammals has disproportionate potential in educating the public about ecological principles and their application to wise management. Mammals have been central to many computational and statistical developments in recent years, including refinements to traditional approaches and metrics (e.g., capture-recapture) as well as advancements of novel and developing fields (e.g., spatial capture-recapture, occupancy modeling, integrated population models). The study of mammals also poses challenges in terms of fully characterizing dynamics in natural conditions. Ongoing climate change threatens to affect global ecosystems, and mammals provide visible and charismatic subjects for research on local and regional effects of such change as well as predictive modeling of the long-term effects on ecosystem function and stability. Although much remains to be done, the population ecology of mammals continues to be a vibrant and rapidly developing field. We anticipate that the next quarter century will prove as exciting and productive for the study of mammals as has the recent one.
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Affiliation(s)
- Douglas A Kelt
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, USA
| | - Edward J Heske
- Museum of Southwestern Biology, University of New Mexico, Albuquerque, NM, USA
| | - Xavier Lambin
- School of Biological Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Madan K Oli
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | - John L Orrock
- Department of Integrative Biology, University of Wisconsin, Madison, WI, USA
| | - Arpat Ozgul
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Jonathan N Pauli
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI, USA
| | - Laura R Prugh
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA
| | - Rahel Sollmann
- Department of Wildlife, Fish, & Conservation Biology, University of California, Davis, CA, USA
| | - Stefan Sommer
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
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25
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Forrester TD, Wittmer HU. Predator identity and forage availability affect predation risk of juvenile black-tailed deer. WILDLIFE BIOLOGY 2019. [DOI: 10.2981/wlb.00510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Tavis D. Forrester
- T. D. Forrester (https://orcid.org/0000-0001-6762-4115) , Dept of Wildlife, Fish and Conservation Biology, Univ. of California, Davis, CA, USA
| | - Heiko U. Wittmer
- H. U. Wittmer, School of Biological Sciences, Victoria Univ. of Wellington, Wellington, New Zealand
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26
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Johnson BK, Jackson DH, Cook RC, Clark DA, Coe PK, Cook JG, Rearden SN, Findholt SL, Noyes JH. Roles of maternal condition and predation in survival of juvenile Elk in Oregon. WILDLIFE MONOGRAPHS 2019. [DOI: 10.1002/wmon.1039] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Bruce K. Johnson
- Oregon Department of Fish and Wildlife; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Dewaine H. Jackson
- Oregon Department of Fish and Wildlife; 4192 N. Umpqua Highway Roseburg OR 97470 USA
| | - Rachel C. Cook
- National Council for Air and Stream Improvement; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Darren A. Clark
- Oregon Department of Fish and Wildlife; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Priscilla K. Coe
- Oregon Department of Fish and Wildlife; 1401 Gekeler Lane La Grande OR 97850 USA
| | - John G. Cook
- National Council for Air and Stream Improvement; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Spencer N. Rearden
- Oregon Cooperative Fish and Wildlife Research Unit; Oregon State University; Corvallis OR 97331 USA
| | - Scott L. Findholt
- Oregon Department of Fish and Wildlife; 1401 Gekeler Lane La Grande OR 97850 USA
| | - James H. Noyes
- Oregon Department of Fish and Wildlife; 1401 Gekeler Lane La Grande OR 97850 USA
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27
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Kämmerle JL, Storch I. Predation, predator control and grouse populations: a review. WILDLIFE BIOLOGY 2019. [DOI: 10.2981/wlb.00464] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
| | - Ilse Storch
- I. Storch, Chair of Wildlife Ecology and Wildlife Management, Univ. of Freiburg, Tennenbacherstraße 4, Freiburg, DE-79106 Freiburg, Germany. JLK also at: Forest Res. Inst. of Baden-Württemberg FVA, Freiburg, Germany
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28
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Strandin T, Babayan SA, Forbes KM. Reviewing the effects of food provisioning on wildlife immunity. Philos Trans R Soc Lond B Biol Sci 2019. [PMID: 29531143 DOI: 10.1098/rstb.2017.0088] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
While urban expansion increasingly encroaches on natural habitats, many wildlife species capitalize on anthropogenic food resources, which have the potential to both positively and negatively influence their responses to infection. Here we examine how food availability and key nutrients have been reported to shape innate and adaptive immunity in wildlife by drawing from field-based studies, as well as captive and food restriction studies with wildlife species. Examples of food provisioning and key nutrients enhancing immune function were seen across the three study type distinctions, as were cases of trace metals and pharmaceuticals impairing the immunity of wildlife species. More generally, food provisioning in field studies tended to increase innate and adaptive responses to certain immune challenges, whereas patterns were less clear in captive studies. Mild food restriction often enhanced, whereas severe food restriction frequently impaired immunity. However, to enable stronger conclusions we stress a need for further research, especially field studies, and highlight the importance of integrating nutritional manipulation, immune challenge, and functional outcomes. Despite current gaps in research on this topic, modern high throughput molecular approaches are increasingly feasible for wildlife studies and offer great opportunities to better understand human influences on wildlife health.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.
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Affiliation(s)
- Tomas Strandin
- Department of Virology, University of Helsinki, Helsinki 00290, Finland
| | - Simon A Babayan
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK.,The Moredun Research Institute, Pentlands Science Park, Penicuik, Midlothian EH26 0PZ, UK
| | - Kristian M Forbes
- Department of Virology, University of Helsinki, Helsinki 00290, Finland .,Center for Infectious Disease Dynamics and Department of Biology, The Pennsylvania State University, University Park, PA 16082, USA
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29
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Kuhnen VV, Wedekin LL, Setz EZF. Coupled population dynamics of two Neotropical marsupials driven by mesopredator's abundance. POPUL ECOL 2019. [DOI: 10.1002/1438-390x.1013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Vanessa V. Kuhnen
- Programa de Pós-Graduação em Ecologia; Instituto de Biologia, Universidade Estadual de Campinas; Campinas Brazil
| | - Leonardo L. Wedekin
- LAGE do Instituto de Biociências, Departamento de Ecologia, Universidade de São Paulo; São Paulo Brazil
| | - Eleonore Z. F. Setz
- Departamento de Biologia Animal; Instituto de Biologia, Universidade Estadual de Campinas; Campinas Brazil
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30
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Ross MV, Alisauskas RT, Douglas DC, Kellett DK. Decadal declines in avian herbivore reproduction: density-dependent nutrition and phenological mismatch in the Arctic. Ecology 2018; 98:1869-1883. [PMID: 28403519 DOI: 10.1002/ecy.1856] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 03/08/2017] [Accepted: 03/31/2017] [Indexed: 11/10/2022]
Abstract
A full understanding of population dynamics depends not only on estimation of mechanistic contributions of recruitment and survival, but also knowledge about the ecological processes that drive each of these vital rates. The process of recruitment in particular may be protracted over several years, and can depend on numerous ecological complexities until sexually mature adulthood is attained. We addressed long-term declines (23 breeding seasons, 1992-2014) in the per capita production of young by both Ross's Geese (Chen rossii) and Lesser Snow Geese (Chen caerulescens caerulescens) nesting at Karrak Lake in Canada's central Arctic. During this period, there was a contemporaneous increase from 0.4 to 1.1 million adults nesting at this colony. We evaluated whether (1) density-dependent nutritional deficiencies of pre-breeding females or (2) phenological mismatch between peak gosling hatch and peak forage quality, inferred from NDVI on the brood-rearing areas, may have been behind decadal declines in the per capita production of goslings. We found that, in years when pre-breeding females arrived to the nesting grounds with diminished nutrient reserves, the proportional composition of young during brood-rearing was reduced for both species. Furthermore, increased mismatch between peak gosling hatch and peak forage quality contributed additively to further declines in gosling production, in addition to declines caused by delayed nesting with associated subsequent negative effects on clutch size and nest success. The degree of mismatch increased over the course of our study because of advanced vegetation phenology without a corresponding advance in Goose nesting phenology. Vegetation phenology was significantly earlier in years with warm surface air temperatures measured in spring (i.e., 25 May-30 June). We suggest that both increased phenological mismatch and reduced nutritional condition of arriving females were behind declines in population-level recruitment, leading to the recent attenuation in population growth of Snow Geese.
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Affiliation(s)
- Megan V Ross
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, S7N 5E2, Canada
| | - Ray T Alisauskas
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, S7N 5E2, Canada.,Environment and Climate Change Canada, 115 Perimeter Road, Saskatoon, Saskatchewan, S7N 0X4, Canada
| | - David C Douglas
- U.S. Geological Survey Alaska Science Center, 250 Egan Drive, Juneau, Alaska, 99801, USA
| | - Dana K Kellett
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan, S7N 5E2, Canada.,Environment and Climate Change Canada, 115 Perimeter Road, Saskatoon, Saskatchewan, S7N 0X4, Canada
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31
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Rowland MM, Wisdom MJ, Nielson RM, Cook JG, Cook RC, Johnson BK, Coe PK, Hafer JM, Naylor BJ, Vales DJ, Anthony RG, Cole EK, Danilson CD, Davis RW, Geyer F, Harris S, Irwin LL, McCoy R, Pope MD, Sager-Fradkin K, Vavra M. Modeling Elk Nutrition and Habitat Use in Western Oregon and Washington. WILDLIFE MONOGRAPHS 2018. [DOI: 10.1002/wmon.1033] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Mary M. Rowland
- U. S. Forest Service Pacific Northwest Research Station; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Michael J. Wisdom
- U. S. Forest Service Pacific Northwest Research Station; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Ryan M. Nielson
- Western EcoSystems Technology (WEST), Inc.; 2121 Midpoint Drive, Suite 201 Fort Collins CO 80525 USA
| | - John G. Cook
- National Council for Air and Stream Improvement; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Rachel C. Cook
- National Council for Air and Stream Improvement; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Bruce K. Johnson
- Oregon Department of Fish and Wildlife; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Priscilla K. Coe
- Oregon Department of Fish and Wildlife; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Jennifer M. Hafer
- U. S. Forest Service Pacific Northwest Research Station; 1401 Gekeler Lane La Grande OR 97850 USA
| | - Bridgett J. Naylor
- U. S. Forest Service Pacific Northwest Research Station; 1401 Gekeler Lane La Grande OR 97850 USA
| | - David J. Vales
- Muckleshoot Indian Tribe; 39015 172nd Avenue SE Auburn WA 98092 USA
| | - Robert G. Anthony
- Oregon State University; 1500 Southwest Jefferson Way Corvallis OR 97331 USA
| | - Eric K. Cole
- U. S. Fish and Wildlife Service; National Elk Refuge; P. O. Box 510, Jackson WY, 83001 USA
| | - Chris D. Danilson
- Washington Department of Fish and Wildlife; Region 4, 111 Sherman Street La Conner WA 98257 USA
| | - Ronald W. Davis
- Department of Natural Resources and Environmental Sciences; University of Illinois at Urbana-Champaign; Urbana IL 61820 USA
| | - Frank Geyer
- Quileute Tribe; 401 Main Street La Push WA 98350 USA
| | - Scott Harris
- Washington Department of Fish and Wildlife; 48 Devonshire Road Montesano WA 98563 USA
| | - Larry L. Irwin
- National Council for Air and Stream Improvement; P. O. Box 68 Stevensville MT 59870 USA
| | - Robert McCoy
- Makah Forestry; P. O. Box 116 Neah Bay WA 98357 USA
| | | | - Kim Sager-Fradkin
- Lower Elwha Klallam Tribe Natural Resources; 760 Stratton Road Port Angeles WA 98363 USA
| | - Martin Vavra
- U. S. Forest Service Pacific Northwest Research Station; 1401 Gekeler Lane La Grande OR 97850 USA
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Fauteux D, Gauthier G, Berteaux D, Palme R, Boonstra R. High Arctic lemmings remain reproductively active under predator-induced elevated stress. Oecologia 2018; 187:657-666. [PMID: 29651661 DOI: 10.1007/s00442-018-4140-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 04/05/2018] [Indexed: 10/17/2022]
Abstract
Non-consumptive effects of predation have rarely been assessed in wildlife populations even though their impact could be as important as lethal effects. Reproduction of individuals is one of the most important demographic parameters that could be affected by predator-induced stress, which in turn can have important consequences on population dynamics. We studied non-consumptive effects of predation on the reproductive activity (i.e., mating and fertilization) of a cyclic population of brown lemmings exposed to intense summer predation in the Canadian High Arctic. Lemmings were live-trapped, their reproductive activity (i.e., testes visible in males, pregnancy/lactation in females) assessed, and predators were monitored during the summers of 2014 and 2015 within a 9 ha predator-reduction exclosure delimited by a fence and covered by a net, and on an 11 ha control area. Stress levels were quantified non-invasively with fecal corticosterone metabolites (FCM). We found that FCM levels of lemmings captured outside the predator exclosure (n = 50) were 1.6 times higher than inside (n = 51). The proportion of pregnant/lactating adult females did not differ between the two areas, nor did the proportion of adult scrotal males. We found that lemmings showed physiological stress reactions due to high predation risk, but had no sign of reduced mating activity or fertility. Thus, our results do not support the hypothesis of reproductive suppression by predator-induced stress.
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Affiliation(s)
- Dominique Fauteux
- Department of Biology and Centre d'études nordiques, Université Laval, 1045 Avenue de la Médecine, Quebec, QC, G1V 0A6, Canada. .,Canadian Museum of Nature, P.O. Box 3443, Station D, Ottawa, ON, K1P 6P4, Canada.
| | - Gilles Gauthier
- Department of Biology and Centre d'études nordiques, Université Laval, 1045 Avenue de la Médecine, Quebec, QC, G1V 0A6, Canada
| | - Dominique Berteaux
- Canada Research Chair on Northern Biodiversity and Centre d'études nordiques, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, QC, G5L 3A1, Canada
| | - Rupert Palme
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Rudy Boonstra
- Centre for the Neurobiology of Stress, Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, ON, M1C 1A4, Canada
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Heffelfinger LJ, Stewart KM, Bush AP, Sedinger JS, Darby NW, Bleich VC. Timing of precipitation in an arid environment: Effects on population performance of a large herbivore. Ecol Evol 2018; 8:3354-3366. [PMID: 29607030 PMCID: PMC5869264 DOI: 10.1002/ece3.3718] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 10/19/2017] [Accepted: 11/08/2017] [Indexed: 11/24/2022] Open
Abstract
Climate models predict that shifts in temperature and precipitation patterns are likely to occur across the globe. Changing climate will likely have strong effects on arid environments as a result of increased temperatures, increasing frequency and intensity of droughts, and less consistent pulses of rainfall. Therefore, understanding the link between patterns of precipitation, temperature, and population performance of species occupying these environments will continue to increase in importance as climatic shifts occur within these natural ecosystems. We sought to evaluate how individual, maternal, population, and environmental, particularly temperature and precipitation, level factors influence population performance of a large herbivore in an arid environment. We used mule deer (Odocoileus hemionus) as a representative species and quantified juvenile survival to test hypotheses about effects of environmental factors on population performance. Precipitation events occurring in mid‐ to late‐pregnancy (January–April) leading to spring green‐up, as indexed by normalized difference in vegetation index, had the strongest positive effect on juvenile survival and recruitment. In addition, larger neonates had an increased probability of survival. Our findings indicate that timing and amount of precipitation prior to parturition have strong influences on maternal nutritional condition, which was passed on to young. These results have important implications for understanding how animal populations may benefit from timing of precipitation during spring and prior to parturition, especially in arid environments.
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Affiliation(s)
- Levi J Heffelfinger
- Department of Natural Resources and Environmental Sciences University of Nevada Reno Reno NV USA
| | - Kelley M Stewart
- Department of Natural Resources and Environmental Sciences University of Nevada Reno Reno NV USA
| | - Anthony P Bush
- Department of Natural Resources and Environmental Sciences University of Nevada Reno Reno NV USA
| | - James S Sedinger
- Department of Natural Resources and Environmental Sciences University of Nevada Reno Reno NV USA
| | - Neal W Darby
- Mojave National Preserve National Park Service Barstow CA USA
| | - Vernon C Bleich
- Department of Natural Resources and Environmental Sciences University of Nevada Reno Reno NV USA.,Sierra Nevada Bighorn Sheep Recovery Program California Department of Fish and Game Bishop California USA
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Ali AH, Kauffman MJ, Amin R, Kibara A, King J, Mallon D, Musyoki C, Goheen JR. Demographic drivers of a refugee species: large-scale experiments guide strategies for reintroductions of hirola. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2018; 28:275-283. [PMID: 29222956 DOI: 10.1002/eap.1664] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 09/28/2017] [Accepted: 10/02/2017] [Indexed: 06/07/2023]
Abstract
Effective reintroduction strategies require accurate estimates of vital rates and the factors that influence them. The hirola (Beatragus hunteri) is the rarest antelope on Earth, with a global population size of <500 individuals restricted to the Kenya-Somali border. We estimated vital rates of hirola populations exposed to varying levels of predation and rangeland quality from 2012 to 2015, and then built population matrices to estimate the finite rate of population change (λ) and demographic sensitivities. Mean survival for all age classes and population growth was highest in the low-predation-high-rangeland-quality setting (λ = 1.08 ± 0.03 [mean ± SE]), and lowest in the high-predation-low-rangeland-quality setting (λ = 0.70 ± 0.22). Retrospective demographic analyses revealed that increased fecundity (the number of female calves born to adult females annually) and female calf survival were responsible for higher population growth where large carnivores were absent. In contrast, variation in adult female survival was the primary contributor to differences in population growth attributable to rangeland quality. Our analyses suggest that hirola demography is driven by a combination of top-down (predation) and bottom-up (rangeland quality) forces, with populations in the contemporary geographic range impacted both by declining rangeland quality and predation. To enhance the chances of successful reintroductions, conservationists can consider rangeland restoration to boost both the survival and fecundity of adult females within the hirola's historical range.
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Affiliation(s)
- Abdullahi H Ali
- Program in Ecology and Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
- National Museums of Kenya, Nairobi, Kenya
- Hirola Conservation Programme, Garissa, Kenya
| | - Matthew J Kauffman
- Program in Ecology and Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
- U.S. Geological Survey, Wyoming Cooperative Fish and Wildlife Research Unit, Laramie, Wyoming, 82071, USA
| | - Rajan Amin
- Conservation Programmes, Zoological Society of London, London, United Kingdom
| | - Amos Kibara
- Hirola Conservation Programme, Garissa, Kenya
| | | | - David Mallon
- IUCN SSP Antelope Specialist Group, Manchester Metropolitan University, Glossop, United Kingdom
| | | | - Jacob R Goheen
- Program in Ecology and Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, USA
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DeWitt PD, Schuler MS, Visscher DR, Thiel RP. Nutritional state reveals complex consequences of risk in a wild predator-prey community. Proc Biol Sci 2017; 284:rspb.2017.0757. [PMID: 28701562 DOI: 10.1098/rspb.2017.0757] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Accepted: 06/09/2017] [Indexed: 11/12/2022] Open
Abstract
Animal populations are regulated by the combined effects of top-down, bottom-up and abiotic processes. Ecologists have struggled to isolate these mechanisms because their effects on prey behaviour, nutrition, security and fitness are often interrelated. We monitored how forage, non-consumptive effects (NCEs), consumptive predation and climatic conditions influenced the demography and nutritional state of a wild prey population during predator recolonization. Combined measures of nutrition, survival and population growth reveal that predators imposed strong effects on the prey population through interacting non-consumptive and consumptive effects, and forage mechanisms. Predation was directly responsible for adult survival, while declining recruitment was attributed to predation risk-sensitive foraging, manifested in poor female nutrition and juvenile recruitment. Substituting nutritional state into the recruitment model through a shared term reveals that predation risk-sensitive foraging was nearly twice as influential as summer forage conditions. Our findings provide a novel, mechanistic insight into the complex means by which predators and forage conditions affect prey populations, and point to a need for more ecological studies that integrate behaviour, nutrition and demography. This line of inquiry can provide further insight into how NCEs interactively contribute to the dynamics of terrestrial prey populations; particularly, how predation risk-sensitive foraging has the potential to stabilize predator-prey coexistence.
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Affiliation(s)
- Philip D DeWitt
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 .,Science and Research Branch, Ontario Ministry of Natural Resources and Forestry, Peterborough, Ontario, Canada K9J 3C7
| | - Matthew S Schuler
- Department of Biological Sciences, Darrin Fresh Water Institute, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Darcy R Visscher
- Department of Biology, The King's University, Alberta, Canada T6B 2H3
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36
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Fauteux D, Gauthier G, Berteaux D. Top-down limitation of lemmings revealed by experimental reduction of predators. Ecology 2017; 97:3231-3241. [PMID: 27870031 DOI: 10.1002/ecy.1570] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 05/31/2016] [Accepted: 07/06/2016] [Indexed: 11/07/2022]
Abstract
It is generally recognized that delayed density-dependence is responsible for cyclic population dynamics. However, it is still uncertain whether a single factor can explain why some rodent populations fluctuate according to a 3-4 yr periodicity. There is increasing evidence that predation may play a role in lemming population cycles, although this effect may vary seasonally. To address this issue, we conducted an experiment where we built a large exclosure (9 ha) to protect brown lemmings (Lemmus trimucronatus) from avian and terrestrial predators. We tested the hypothesis that predation is a limiting factor for lemmings by measuring the demographic consequences of a predator reduction during the growth and peak phases of the cycle. We assessed summer (capture-mark-recapture methods) and winter (winter nest sampling) lemming demography on two grids located on Bylot Island, Nunavut, Canada from 2008 to 2015. The predator exclosure became fully effective in July 2013, allowing us to compare demography between the control and experimental grids before and during the treatment. Lemming abundance, survival and proportion of juveniles were similar between the two grids before the treatment. During the predator-reduction period, summer densities were on average 1.9× higher inside the experimental grid than the control and this effect was greatest for adult females and juveniles (densities 2.4× and 3.4× higher, respectively). Summer survival was 1.6× higher on the experimental grid than the control whereas body mass and proportion of juveniles were also slightly higher. Winter nest densities remained high inside the predator reduction grid following high summer abundance, but declined on the control grid. These results confirm that predation limits lemming population growth during the summer due to its negative impact on survival. However, it is possible that in winter, predation may interact with other factors affecting reproduction and ultimately population cycles.
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Affiliation(s)
- Dominique Fauteux
- Department of Biology and Centre d'Études Nordiques, Université Laval, 1045 Avenue de la Médecine, Québec, Québec, G1V 0A6, Canada
| | - Gilles Gauthier
- Department of Biology and Centre d'Études Nordiques, Université Laval, 1045 Avenue de la Médecine, Québec, Québec, G1V 0A6, Canada
| | - Dominique Berteaux
- Canada Research Chair on Northern Biodiversity and Centre d'Études Nordiques, Université du Québec à Rimouski, 300 Allée des Ursulines, Rimouski, Québec, G5L 3A1, Canada
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Azad S, Wactor T, Jachowski D. Relationship of Acorn Mast Production to Black Bear Population Growth Rates and Human—Bear Interactions in Northwestern South Carolina. SOUTHEAST NAT 2017. [DOI: 10.1656/058.016.0210] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Shefali Azad
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29634-0317
| | - Tammy Wactor
- Wildlife and Freshwater Fisheries, South Carolina Department of Natural Resources, Clemson, SC 29631
| | - David Jachowski
- Department of Forestry and Environmental Conservation, Clemson University, Clemson, SC 29634-0317
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Flowerdew JR, Amano T, Sutherland WJ. Strong "bottom-up" influences on small mammal populations: State-space model analyses from long-term studies. Ecol Evol 2017; 7:1699-1711. [PMID: 28331581 PMCID: PMC5355190 DOI: 10.1002/ece3.2725] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/25/2016] [Accepted: 12/18/2016] [Indexed: 11/07/2022] Open
Abstract
“Bottom‐up” influences, that is, masting, plus population density and climate, commonly influence woodland rodent demography. However, “top‐down” influences (predation) also intervene. Here, we assess the impacts of masting, climate, and density on rodent populations placed in the context of what is known about “top‐down” influences. To explain between‐year variations in bank vole Myodes glareolus and wood mouse Apodemus sylvaticus population demography, we applied a state‐space model to 33 years of catch‐mark‐release live‐trapping, winter temperature, and precise mast‐collection data. Experimental mast additions aided interpretation. Rodent numbers in European ash Fraxinus excelsior woodland were estimated (May/June, November/December). December–March mean minimum daily temperature represented winter severity. Total marked adult mice/voles (and juveniles in May/June) provided density indices validated against a model‐generated population estimate; this allowed estimation of the structure of a time‐series model and the demographic impacts of the climatic/biological variables. During two winters of insignificant fruit‐fall, 6.79 g/m2 sterilized ash seed (as fruit) was distributed over an equivalent woodland similarly live‐trapped. September–March fruit‐fall strongly increased bank vole spring reproductive rate and winter and summer population growth rates; colder winters weakly reduced winter population growth. September–March fruit‐fall and warmer winters marginally increased wood mouse spring reproductive rate and September–December fruit‐fall weakly elevated summer population growth. Density dependence significantly reduced both species' population growth. Fruit‐fall impacts on demography still appeared after a year. Experimental ash fruit addition confirmed its positive influence on bank vole winter population growth with probable moderation by colder temperatures. The models show the strong impact of masting as a “bottom‐up” influence on rodent demography, emphasizing independent masting and weather influences; delayed effects of masting; and the importance of density dependence and its interaction with masting. We conclude that these rodents show strong “bottom‐up” and density‐dependent influences on demography moderated by winter temperature. “Top‐down” influences appear weak and need further investigation.
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Affiliation(s)
| | - Tatsuya Amano
- Department of Zoology University of Cambridge Cambridge UK
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Tallian A, Ordiz A, Metz MC, Milleret C, Wikenros C, Smith DW, Stahler DR, Kindberg J, MacNulty DR, Wabakken P, Swenson JE, Sand H. Competition between apex predators? Brown bears decrease wolf kill rate on two continents. Proc Biol Sci 2017; 284:20162368. [PMID: 28179516 PMCID: PMC5310606 DOI: 10.1098/rspb.2016.2368] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 01/16/2017] [Indexed: 11/12/2022] Open
Abstract
Trophic interactions are a fundamental topic in ecology, but we know little about how competition between apex predators affects predation, the mechanism driving top-down forcing in ecosystems. We used long-term datasets from Scandinavia (Europe) and Yellowstone National Park (North America) to evaluate how grey wolf (Canis lupus) kill rate was affected by a sympatric apex predator, the brown bear (Ursus arctos). We used kill interval (i.e. the number of days between consecutive ungulate kills) as a proxy of kill rate. Although brown bears can monopolize wolf kills, we found no support in either study system for the common assumption that they cause wolves to kill more often. On the contrary, our results showed the opposite effect. In Scandinavia, wolf packs sympatric with brown bears killed less often than allopatric packs during both spring (after bear den emergence) and summer. Similarly, the presence of bears at wolf-killed ungulates was associated with wolves killing less often during summer in Yellowstone. The consistency in results between the two systems suggests that brown bear presence actually reduces wolf kill rate. Our results suggest that the influence of predation on lower trophic levels may depend on the composition of predator communities.
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Affiliation(s)
- Aimee Tallian
- Department of Wildland Resources and Ecology Center, Utah State University, 5230 Old Main Hill, Logan, UT 84322, USA
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 730 91 Riddarhyttan, Sweden
| | - Andrés Ordiz
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 730 91 Riddarhyttan, Sweden
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Postbox 5003, 1432 Ås, Norway
| | - Matthew C Metz
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT 59812, USA
- Yellowstone Center for Resources, Yellowstone National Park, Box 168, Mammoth Hot Springs, WY 82190, USA
| | - Cyril Milleret
- Faculty of Applied Ecology and Agricultural Sciences, Inland Norway University of Applied Sciences, Evenstad, 2480 Koppang, Norway
| | - Camilla Wikenros
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 730 91 Riddarhyttan, Sweden
| | - Douglas W Smith
- Yellowstone Center for Resources, Yellowstone National Park, Box 168, Mammoth Hot Springs, WY 82190, USA
| | - Daniel R Stahler
- Yellowstone Center for Resources, Yellowstone National Park, Box 168, Mammoth Hot Springs, WY 82190, USA
| | - Jonas Kindberg
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden
- Norwegian Institute for Nature Research, 7485 Trondheim, Norway
| | - Daniel R MacNulty
- Department of Wildland Resources and Ecology Center, Utah State University, 5230 Old Main Hill, Logan, UT 84322, USA
| | - Petter Wabakken
- Faculty of Applied Ecology and Agricultural Sciences, Inland Norway University of Applied Sciences, Evenstad, 2480 Koppang, Norway
| | - Jon E Swenson
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Postbox 5003, 1432 Ås, Norway
- Norwegian Institute for Nature Research, 7485 Trondheim, Norway
| | - Håkan Sand
- Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, 730 91 Riddarhyttan, Sweden
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Fernández N, Román J, Delibes M. Variability in primary productivity determines metapopulation dynamics. Proc Biol Sci 2016; 283:rspb.2015.2998. [PMID: 27053739 PMCID: PMC4843648 DOI: 10.1098/rspb.2015.2998] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/14/2016] [Indexed: 11/12/2022] Open
Abstract
Temporal variability in primary productivity can change habitat quality for consumer species by affecting the energy levels available as food resources. However, it remains unclear how habitat-quality fluctuations may determine the dynamics of spatially structured populations, where the effects of habitat size, quality and isolation have been customarily assessed assuming static habitats. We present the first empirical evaluation on the effects of stochastic fluctuations in primary productivity—a major outcome of ecosystem functions—on the metapopulation dynamics of a primary consumer. A unique 13-year dataset from an herbivore rodent was used to test the hypothesis that inter-annual variations in primary productivity determine spatiotemporal habitat occupancy patterns and colonization and extinction processes. Inter-annual variability in productivity and in the growing season phenology significantly influenced habitat colonization patterns and occupancy dynamics. These effects lead to changes in connectivity to other potentially occupied habitat patches, which then feed back into occupancy dynamics. According to the results, the dynamics of primary productivity accounted for more than 50% of the variation in occupancy probability, depending on patch size and landscape configuration. Evidence connecting primary productivity dynamics and spatiotemporal population processes has broad implications for metapopulation persistence in fluctuating and changing environments.
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Affiliation(s)
- Néstor Fernández
- Department of Conservation Biology, Estación Biológica de Doñana, Spanish Council for Scientific Research EBD-CSIC, Seville 41092, Spain
| | - Jacinto Román
- Department of Conservation Biology, Estación Biológica de Doñana, Spanish Council for Scientific Research EBD-CSIC, Seville 41092, Spain
| | - Miguel Delibes
- Department of Conservation Biology, Estación Biológica de Doñana, Spanish Council for Scientific Research EBD-CSIC, Seville 41092, Spain
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Bijleveld AI, MacCurdy RB, Chan YC, Penning E, Gabrielson RM, Cluderay J, Spaulding EL, Dekinga A, Holthuijsen S, ten Horn J, Brugge M, van Gils JA, Winkler DW, Piersma T. Understanding spatial distributions: negative density-dependence in prey causes predators to trade-off prey quantity with quality. Proc Biol Sci 2016; 283:rspb.2015.1557. [PMID: 27053747 DOI: 10.1098/rspb.2015.1557] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 03/04/2016] [Indexed: 11/12/2022] Open
Abstract
Negative density-dependence is generally studied within a single trophic level, thereby neglecting its effect on higher trophic levels. The 'functional response' couples a predator's intake rate to prey density. Most widespread is a type II functional response, where intake rate increases asymptotically with prey density; this predicts the highest predator densities at the highest prey densities. In one of the most stringent tests of this generality to date, we measured density and quality of bivalve prey (edible cockles Cerastoderma edule) across 50 km² of mudflat, and simultaneously, with a novel time-of-arrival methodology, tracked their avian predators (red knots Calidris canutus). Because of negative density-dependence in the individual quality of cockles, the predicted energy intake rates of red knots declined at high prey densities (a type IV, rather than a type II functional response). Resource-selection modelling revealed that red knots indeed selected areas of intermediate cockle densities where energy intake rates were maximized given their phenotype-specific digestive constraints (as indicated by gizzard mass). Because negative density-dependence is common, we question the current consensus and suggest that predators commonly maximize their energy intake rates at intermediate prey densities. Prey density alone may thus poorly predict intake rates, carrying capacity and spatial distributions of predators.
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Affiliation(s)
- Allert I Bijleveld
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - Robert B MacCurdy
- Department of Mechanical and Aerospace Engineering, Cornell University, Corson Hall, Ithaca, NY 14853, USA
| | - Ying-Chi Chan
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - Emma Penning
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - Rich M Gabrielson
- Department of Ecology and Evolutionary Biology, Cornell University, Corson Hall, Ithaca, NY 14853, USA Bioacoustics Research Program, Cornell Laboratory of Ornithology, Cornell University, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA
| | - John Cluderay
- NIOZ Royal Netherlands Institute for Sea Research, National Marine Facilities, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - Eric L Spaulding
- Bioacoustics Research Program, Cornell Laboratory of Ornithology, Cornell University, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA
| | - Anne Dekinga
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - Sander Holthuijsen
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - Job ten Horn
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - Maarten Brugge
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - Jan A van Gils
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands
| | - David W Winkler
- Department of Ecology and Evolutionary Biology, Cornell University, Corson Hall, Ithaca, NY 14853, USA
| | - Theunis Piersma
- NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, PO Box 59, 1790 AB Den Burg, The Netherlands Chair in Global Flyway Ecology, Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, PO Box 11103, 9700 CC Groningen, The Netherlands
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43
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Werner JR, Gillis EA, Boonstra R, Krebs CJ. You can hide but you can't run: apparent competition, predator responses and the decline of Arctic ground squirrels in boreal forests of the southwest Yukon. PeerJ 2016; 4:e2303. [PMID: 27635312 PMCID: PMC5012268 DOI: 10.7717/peerj.2303] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 07/07/2016] [Indexed: 11/20/2022] Open
Abstract
Throughout much of North America's boreal forest, the cyclical fluctuations of snowshoe hare populations (Lepus americanus) may cause other herbivores to become entrained in similar cycles. Alternating apparent competition via prey switching followed by positive indirect effects are the mechanisms behind this interaction. Our purpose is to document a change in the role of indirect interactions between sympatric populations of hares and arctic ground squirrels (Urocitellus parryii plesius), and to emphasize the influence of predation for controlling ground squirrel numbers. We used mark-recapture to estimate the population densities of both species over a 25-year period that covered two snowshoe hare cycles. We analysed the strength of association between snowshoe hare and ground squirrel numbers, and the changes to the seasonal and annual population growth rates of ground squirrels over time. A hyperbolic curve best describes the per capita rate of increase of ground squirrels relative to their population size, with a single stable equilibrium and a lower critical threshold below which populations drift to extinction. The crossing of this unstable boundary resulted in the subsequent uncoupling of ground squirrel and hare populations following the decline phase of their cycles in 1998. The implications are that this sustained Type II predator response led to the local extinction of ground squirrels. When few individuals are left in a colony, arctic ground squirrels may also have exhibited an Allee effect caused by the disruption of social signalling of approaching predators.
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Affiliation(s)
- Jeffery R Werner
- Biodiversity Research Centre, Department of Zoology, University of British Columbia , Vancouver , British Columbia , Canada
| | - Elizabeth A Gillis
- Department of Resource Management and Protection, Vancouver Island University , Nanaimo , British Columbia , Canada
| | - Rudy Boonstra
- Department of Biological Sciences, University of Toronto, Scarborough , Toronto , Ontario , Canada
| | - Charles J Krebs
- Department of Zoology, University of British Columbia , Vancouver , British Columbia , Canada
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Unnsteinsdottir ER, Hersteinsson P, Pálsson S, Angerbjörn A. The fall and rise of the Icelandic Arctic fox (Vulpes lagopus): a 50-year demographic study on a non-cyclic Arctic fox population. Oecologia 2016; 181:1129-38. [PMID: 27126366 DOI: 10.1007/s00442-016-3635-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/12/2016] [Indexed: 11/30/2022]
Abstract
In territorial species, observed density dependence is often manifest in lowered reproductive output at high population density where individuals have fewer resources or are forced to inhabit low-quality territories. The Arctic fox (Vulpes lagopus) in Iceland is territorial throughout the year and feeds mostly on birds, since lemmings are absent from the country. Thus, the population does not exhibit short-term population cycles that are evident in most of the species' geographical range. The population has, however, gone through a major long-term fluctuation in population size. Because of the stability in hunting effort and reliable hunting records since 1958, the total number of adult foxes killed annually can be used as an index of population size (N t ). An index of carrying capacity (K) from population growth data for five separate time blocks during 1958-2007 revealed considerable variation in K and allowed a novel definition of population density in terms of K, or N t /K. Correlation analysis suggested that the reproductive rate was largely determined by the proportion of territorial foxes in the population. Variation in litter size and cub mortality was, on the other hand, related to climatic variation. Thus, Arctic foxes in Iceland engage in typical contest competition but can adapt their territory sizes in response to both temporal and spatial variation in carrying capacity, resulting in surprisingly little variation in litter size.
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Affiliation(s)
- E R Unnsteinsdottir
- The Icelandic Institute of Natural History, Urridaholtsstraeti 6-8, P.O. Box 125, 212, Gardabaer, Iceland.
| | - P Hersteinsson
- Institute of Biology, University of Iceland, Sturlugata 7, 101, Reykjavik, Iceland
| | - S Pálsson
- Institute of Biology, University of Iceland, Sturlugata 7, 101, Reykjavik, Iceland
| | - A Angerbjörn
- Department of Zoology, Stockholm University, 106 91, Stockholm, Sweden
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Davis ML, Stephens PA, Kjellander P. Beyond climate envelope projections: Roe deer survival and environmental change. J Wildl Manage 2016. [DOI: 10.1002/jwmg.1029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Miranda L. Davis
- School of Biological and Biomedical Sciences; University of Durham; County Durham DH1 3LE United Kingdom
| | - Philip A. Stephens
- School of Biological and Biomedical Sciences; University of Durham; County Durham DH1 3LE United Kingdom
| | - Petter Kjellander
- Department of Ecology, Grimsö Wildlife Research Station; Swedish University of Agricultural Sciences (SLU); Riddarhyttan Sweden
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Garnick S, Di Stefano J, Elgar MA, Coulson G. Ecological specialisation in habitat selection within a macropodid herbivore guild. Oecologia 2015; 180:823-32. [PMID: 26621691 DOI: 10.1007/s00442-015-3510-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 11/10/2015] [Indexed: 10/22/2022]
Abstract
Specialist species show stronger resource selection, narrower niches and lower niche overlap than generalist species. We examined ecological specialisation with respect to habitat selection in a macropodid community comprising the western grey kangaroo Macropus fuliginosus, red-necked wallaby M. rufogriseus and swamp wallaby Wallabia bicolor in the Grampians National Park, Victoria, Australia. We used radio tracking to quantify habitat selection. We predicted that because the fitness benefits of generalisation and specialisation differ, there would be a mix of generalised and specialised species in our community. As all three macropodid species show marked sexual dimorphism, we also expected that they would show sex-based specialisation. Finally, because many large herbivores select different habitats for foraging and resting, we predicted that our species would specialise on a subset of their overall selected habitat based on activity period (diurnal or nocturnal). All three species specialised on the available resources to some degree. Western grey kangaroos were specialists, at least during the active period. Niche data for the two wallaby species were harder to interpret so we could not determine their degree of specialisation. Within species, we found no evidence of sex-based specialisation. However, we found clear evidence of specialisation by activity period in western grey kangaroos and red-necked wallabies, but not in swamp wallabies. The strength of behavioural decisions made during the active period in influencing specialisation points to the likelihood that bottom-up processes regulate this community.
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Affiliation(s)
- Sarah Garnick
- School of BioSciences, University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Julian Di Stefano
- School of Ecosystem and Forest Science, University of Melbourne, Creswick, VIC, 3363, Australia.
| | - Mark A Elgar
- School of BioSciences, University of Melbourne, Melbourne, VIC, 3010, Australia.
| | - Graeme Coulson
- School of BioSciences, University of Melbourne, Melbourne, VIC, 3010, Australia.
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Ordiz A, Milleret C, Kindberg J, Månsson J, Wabakken P, Swenson JE, Sand H. Wolves, people, and brown bears influence the expansion of the recolonizing wolf population in Scandinavia. Ecosphere 2015. [DOI: 10.1890/es15-00243.1] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Vogel ER, Harrison ME, Zulfa A, Bransford TD, Alavi SE, Husson S, Morrogh-Bernard H, Santiano, Firtsman T, Utami-Atmoko SS, van Noordwijk MA, Farida WR. Nutritional Differences between Two Orangutan Habitats: Implications for Population Density. PLoS One 2015; 10:e0138612. [PMID: 26466370 PMCID: PMC4605688 DOI: 10.1371/journal.pone.0138612] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 08/31/2015] [Indexed: 11/18/2022] Open
Abstract
Bottom-up regulatory factors have been proposed to exert a strong influence on mammalian population density. Studies relating habitat quality to population density have typically made comparisons among distant species or communities without considering variation in food quality among localities. We compared dietary nutritional quality of two Bornean orangutan populations with differing population densities in peatland habitats, Tuanan and Sabangau, separated by 63 km. We hypothesized that because Tuanan is alluvial, the plant species included in the orangutan diet would be of higher nutritional quality compared to Sabangau, resulting in higher daily caloric intake in Tuanan. We also predicted that forest productivity would be greater in Tuanan compared to Sabangau. In support of these hypotheses, the overall quality of the diet and the quality of matched dietary items were higher in Tuanan, resulting in higher daily caloric intake compared to Sabangau. These differences in dietary nutritional quality may provide insights into why orangutan population density is almost two times greater in Tuanan compared to Sabangau, in agreement with a potentially important influence of diet quality on primate population density.
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Affiliation(s)
- Erin R. Vogel
- Department of Anthropology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Mark E. Harrison
- Department of Geography, University of Leicester, Leicester, United Kingdom
- The Orangutan Tropical Peatland Project, Palangka Raya, Indonesia
| | - Astri Zulfa
- Fakultas Biologi, Universitas Nasional Jakarta, Jakarta, Indonesia
| | - Timothy D. Bransford
- Department of Anthropology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Shauhin E. Alavi
- Department of Anthropology, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Simon Husson
- The Orangutan Tropical Peatland Project, Palangka Raya, Indonesia
| | | | - Santiano
- The Orangutan Tropical Peatland Project, Palangka Raya, Indonesia
- Centre for the International Cooperation in Sustainable Management of Tropical Peatlands, Palangka Raya, Indonesia
| | - Twentinolosa Firtsman
- The Orangutan Tropical Peatland Project, Palangka Raya, Indonesia
- Centre for the International Cooperation in Sustainable Management of Tropical Peatlands, Palangka Raya, Indonesia
| | | | | | - Wartika Rosa Farida
- Research Center for Biology, Indonesian Institute of Sciences (LIPI), Cibinong-Bogor, Indonesia
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Can widespread generalist predators affect keystone prey? A case study with red foxes and European rabbits in their native range. POPUL ECOL 2015. [DOI: 10.1007/s10144-015-0510-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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50
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McLellan BN. Some mechanisms underlying variation in vital rates of grizzly bears on a multiple use landscape. J Wildl Manage 2015. [DOI: 10.1002/jwmg.896] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Bruce N. McLellan
- BC Ministry of Forests; Lands and Natural Resource Operations, P.O. Box 1732; D'Arcy B.C. V0N 1L0 Canada
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