1
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Park KY, Lucas M, Chaulk A, Matter SF, Roland J, Keyghobadi N. Immigration allows population persistence and maintains genetic diversity despite an attempted experimental extinction. ROYAL SOCIETY OPEN SCIENCE 2024; 11:240557. [PMID: 39086829 PMCID: PMC11288673 DOI: 10.1098/rsos.240557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/07/2024] [Accepted: 07/08/2024] [Indexed: 08/02/2024]
Abstract
Widespread fragmentation and degradation of habitats make organisms increasingly vulnerable to declines in population size. Immigration is a key process potentially affecting the rescue and persistence of populations in the face of such pressures. Field research addressing severe demographic declines in the context of immigration among interconnected local populations is limited owing to difficulties in detecting such demographic events and the need for long-term monitoring of populations. In a 17-subpopulation metapopulation of the butterfly, Parnassius smintheus, all adults observed in two adjacent patches were removed over eight consecutive generations. Despite this severe and long-term reduction in survival and reproduction, the targeted populations did not go extinct. Here, we use genetic data to assess the role of immigration versus in situ reproduction in allowing the persistence of these populations. We genotyped 471 samples collected from the targeted populations throughout the removal experiment at 152 single nucleotide polymorphisms. We found no reduction in the genetic diversity of the targeted populations over time, but a decrease in the number of loci in Hardy-Weinberg equilibrium, consistent with a high level of immigration from multiple surrounding populations. Our results highlight the role of connectivity and movement in making metapopulations resilient to even severe and protracted localized population reductions.
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Affiliation(s)
- Keon Young Park
- Department of Biology, Western University, London, OntarioN6A 5B7, Canada
| | - Mel Lucas
- Department of Biology, Western University, London, OntarioN6A 5B7, Canada
| | - Andrew Chaulk
- Department of Biology, Western University, London, OntarioN6A 5B7, Canada
- Department of Biology, Memorial University of Newfoundland, St John’s, NewfoundlandA1C 5S7, Canada
| | - Stephen F. Matter
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH45221, USA
| | - Jens Roland
- Department of Biological Sciences, University of Alberta, Edmonton, AlbertaT6G 2E9, Canada
| | - Nusha Keyghobadi
- Department of Biology, Western University, London, OntarioN6A 5B7, Canada
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2
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Summers J, Cosgrove EJ, Bowman R, Fitzpatrick JW, Chen N. Impacts of increasing isolation and environmental variation on Florida Scrub-Jay demography. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.10.575127. [PMID: 38260596 PMCID: PMC10802623 DOI: 10.1101/2024.01.10.575127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Isolation caused by anthropogenic habitat fragmentation can destabilize populations. Populations relying on the inflow of immigrants can face reduced fitness due to inbreeding depression as fewer new individuals arrive. Empirical studies of the demographic consequences of isolation are critical to understand how populations persist through changing conditions. We used a 34-year demographic and environmental dataset from a population of cooperatively-breeding Florida Scrub-Jays ( Aphelocoma coerulescens ) to create mechanistic models linking environmental and demographic factors to population growth rates. We found that the population has not declined despite both declining immigration and increasing inbreeding, owing to a coinciding response in breeder survival. We find evidence of density-dependent immigration, breeder survival, and fecundity, indicating that interactions between vital rates and local density play a role in buffering the population against change. Our study elucidates the impacts of isolation on demography and how long-term stability is maintained via demographic responses.
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3
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Christian M, Oosthuizen WC, Bester MN, de Bruyn PJN. Robustly estimating the demographic contribution of immigration: Simulation, sensitivity analysis and seals. J Anim Ecol 2024; 93:632-645. [PMID: 38297453 DOI: 10.1111/1365-2656.14053] [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: 10/04/2023] [Accepted: 01/11/2024] [Indexed: 02/02/2024]
Abstract
Identifying important demographic drivers of population dynamics is fundamental for understanding life-history evolution and implementing effective conservation measures. Integrated population models (IPMs) coupled with transient life table response experiments (tLTREs) allow ecologists to quantify the contributions of demographic parameters to observed population change. While IPMs can estimate parameters that are not estimable using any data source alone, for example, immigration, the estimated contribution of such parameters to population change is prone to bias. Currently, it is unclear when robust conclusions can be drawn from them. We sought to understand the drivers of a rebounding southern elephant seal population on Marion Island using the IPM-tLTRE framework, applied to count and mark-recapture data on 9500 female seals over nearly 40 years. Given the uncertainty around IPM-tLTRE estimates of immigration, we also aimed to investigate the utility of simulation and sensitivity analyses as general tools for evaluating the robustness of conclusions obtained in this framework. Using a Bayesian IPM and tLTRE analysis, we quantified the contributions of survival, immigration and population structure to population growth. We assessed the sensitivity of our estimates to choice of multivariate priors on immigration and other vital rates. To do so we make a novel application of Gaussian process priors, in comparison with commonly used shrinkage priors. Using simulation, we assessed our model's ability to estimate the demographic contribution of immigration under different levels of temporal variance in immigration. The tLTRE analysis suggested that adult survival and immigration were the most important drivers of recent population growth. While the contribution of immigration was sensitive to prior choices, the estimate was consistently large. Furthermore, our simulation study validated the importance of immigration by showing that our estimate of its demographic contribution is unlikely to result as a biased overestimate. Our results highlight the connectivity between distant populations of southern elephant seals, illustrating that female dispersal can be important in regulating the abundance of local populations even when natal site fidelity is high. More generally, we demonstrate how robust ecological conclusions may be obtained about immigration from the IPM-tLTRE framework, by combining sensitivity analysis and simulation.
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Affiliation(s)
- Murray Christian
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Hatfield, South Africa
- Centre for Statistics in Ecology, the Environment and Conservation, Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa
| | - W Chris Oosthuizen
- Centre for Statistics in Ecology, the Environment and Conservation, Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa
| | - Marthán N Bester
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Hatfield, South Africa
| | - P J Nico de Bruyn
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Hatfield, South Africa
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4
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Hogg CJ. Translating genomic advances into biodiversity conservation. Nat Rev Genet 2024; 25:362-373. [PMID: 38012268 DOI: 10.1038/s41576-023-00671-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2023] [Indexed: 11/29/2023]
Abstract
A key action of the new Global Biodiversity Framework is the maintenance of genetic diversity in all species to safeguard their adaptive potential. To achieve this goal, a translational mindset, which aims to convert results of basic research into direct practical benefits, needs to be applied to biodiversity conservation. Despite much discussion on the value of genomics to conservation, a disconnect between those generating genomic resources and those applying it to biodiversity management remains. As global efforts to generate reference genomes for non-model species increase, investment into practical biodiversity applications is critically important. Applications such as understanding population and multispecies diversity and longitudinal monitoring need support alongside education for policymakers on integrating the data into evidence-based decisions. Without such investment, the opportunity to revolutionize global biodiversity conservation using genomics will not be fully realized.
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Affiliation(s)
- Carolyn J Hogg
- School of Life & Environmental Sciences, The University of Sydney, Sydney, NSW, Australia.
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5
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Nater CR. Redefining 'state-of-the-art' for integrated population models with immigration. J Anim Ecol 2024; 93:520-524. [PMID: 38634153 DOI: 10.1111/1365-2656.14087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 03/22/2024] [Indexed: 04/19/2024]
Abstract
Research Highlight: Christian, M., Oosthuizen, W. C., Bester, M. N., & de Bruyn, P. N. (2024). Robustly estimating the demographic contribution of immigration: Simulation, sensitivity analysis and seals. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.14053. Immigration can have profound consequences for local population dynamics and demography, but collecting data to accurately quantifying it is challenging. The recent rise of integrated population models (IPMs) offers an alternative by making it possible to estimate immigration without the need for explicit data, and to quantify its contribution to population dynamics through transient Life Table Response Experiments (tLTREs). Simulation studies have, however, highlighted that this approach can be prone to bias and overestimation. In their new study, Christian et al. address one of the root causes of this issue by improving the estimation of time variation in vital rates and immigration using Gaussian processes in lieu of traditionally used temporal random effects. They demonstrate that IPM-tLTRE frameworks with Gaussian processes produce more accurate and less biased estimates of immigration and its contribution to population dynamics and illustrate the applicability of this approach using a long-term data set on elephant seals (Mirounga leonida). Results are validated with a simulation study and suggest that immigration of breeding females has been central for population recovery of elephant seals despite the species' high female site fidelity. Christian et al. thus present new insights into population regulation of long-lived marine mammals and highlight the potential for using Gaussian process priors in IPMs. They also illustrate a suite of 'best practices' for state-of-the-art IPM-tLTRE analyses and provide an inspirational example for the kind of ecological modelling workflow that can be invaluable not just as a starting point for fellow ecologists picking up or improving their own IPM-tLTRE analyses, but also for teaching and in contexts where model estimates are used for informing management and conservation decision-making.
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Affiliation(s)
- Chloé R Nater
- Norwegian Institute of Nature Research (NINA), Trondheim, Norway
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6
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Saatoglu D, Lundregan SL, Fetterplace E, Goedert D, Husby A, Niskanen AK, Muff S, Jensen H. The genetic basis of dispersal in a vertebrate metapopulation. Mol Ecol 2024; 33:e17295. [PMID: 38396362 DOI: 10.1111/mec.17295] [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: 08/18/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/25/2024]
Abstract
Dispersal affects evolutionary processes by changing population size and genetic composition, influencing the viability and persistence of populations. Investigating which mechanisms underlie variation in dispersal phenotypes and whether populations harbour adaptive potential for dispersal is crucial to understanding the eco-evolutionary dynamics of this important trait. Here, we investigate the genetic architecture of dispersal among successfully recruited individuals in an insular metapopulation of house sparrows. We use an extensive long-term individual-based ecological data set and high-density single-nucleotide polymorphism (SNP) genotypes for over 2500 individuals. We conducted a genome-wide association study (GWAS), and found a relationship between dispersal probability and a SNP located near genes known to regulate circadian rhythm, glycogenesis and exercise performance, among other functions. However, this SNP only explained 3.8% of variance, suggesting that dispersal is a polygenic trait. We then used an animal model to estimate heritable genetic variation (σA 2 ), which composes 10% of the total variation in dispersal probability. Finally, we investigated differences in σA 2 across populations occupying ecologically relevant habitat types (farm vs. non-farm) using a genetic groups animal model. We found different adaptive potentials across habitats, with higher mean breeding value, σA 2 , and heritability for the habitat presenting lower dispersal rates, suggesting also different roles of environmental variation. Our results suggest a complex genetic architecture of dispersal and demonstrate that adaptive potential may be environment dependent in key eco-evolutionary traits. The eco-evolutionary implications of such environment dependence and consequent spatial variation are likely to become ever more important with the increased fragmentation and loss of suitable habitats for many natural populations.
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Affiliation(s)
- Dilan Saatoglu
- Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Sarah L Lundregan
- Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Evelyn Fetterplace
- Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Debora Goedert
- Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Arild Husby
- Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
- Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Alina K Niskanen
- Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
| | - Stefanie Muff
- Department of Mathematical Sciences, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Henrik Jensen
- Department of Biology, Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
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7
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Dickel L, Arcese P, Keller LF, Nietlisbach P, Goedert D, Jensen H, Reid JM. Multigenerational Fitness Effects of Natural Immigration Indicate Strong Heterosis and Epistatic Breakdown in a Wild Bird Population. Am Nat 2024; 203:411-431. [PMID: 38358807 DOI: 10.1086/728669] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
AbstractThe fitness of immigrants and their descendants produced within recipient populations fundamentally underpins the genetic and population dynamic consequences of immigration. Immigrants can in principle induce contrasting genetic effects on fitness across generations, reflecting multifaceted additive, dominance, and epistatic effects. Yet full multigenerational and sex-specific fitness effects of regular immigration have not been quantified within naturally structured systems, precluding inference on underlying genetic architectures and population outcomes. We used four decades of song sparrow (Melospiza melodia) life history and pedigree data to quantify fitness of natural immigrants, natives, and their F1, F2, and backcross descendants and test for evidence of nonadditive genetic effects. Values of key fitness components (including adult lifetime reproductive success and zygote survival) of F1 offspring of immigrant-native matings substantially exceeded their parent mean, indicating strong heterosis. Meanwhile, F2 offspring of F1-F1 matings had notably low values, indicating surprisingly strong epistatic breakdown. Furthermore, magnitudes of effects varied among fitness components and differed between female and male descendants. These results demonstrate that strong nonadditive genetic effects on fitness can arise within weakly structured and fragmented populations experiencing frequent natural immigration. Such effects will substantially affect the net degree of effective gene flow and resulting local genetic introgression and adaptation.
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8
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Reid JM, Dickel L, Keller LF, Nietlisbach P, Arcese P. Multi-generation genetic contributions of immigrants reveal cryptic elevated and sex-biased effective gene flow within a natural meta-population. Ecol Lett 2024; 27:e14377. [PMID: 38361472 DOI: 10.1111/ele.14377] [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: 09/12/2023] [Revised: 01/11/2024] [Accepted: 01/11/2024] [Indexed: 02/17/2024]
Abstract
Impacts of immigration on micro-evolution and population dynamics fundamentally depend on net rates and forms of resulting gene flow into recipient populations. Yet, the degrees to which observed rates and sex ratios of physical immigration translate into multi-generational genetic legacies have not been explicitly quantified in natural meta-populations, precluding inference on how movements translate into effective gene flow and eco-evolutionary outcomes. Our analyses of three decades of complete song sparrow (Melospiza melodia) pedigree data show that multi-generational genetic contributions from regular natural immigrants substantially exceeded those from contemporary natives, consistent with heterosis-enhanced introgression. However, while contributions from female immigrants exceeded those from female natives by up to three-fold, male immigrants' lineages typically went locally extinct soon after arriving. Both the overall magnitude, and the degree of female bias, of effective gene flow therefore greatly exceeded those which would be inferred from observed physical arrivals, altering multiple eco-evolutionary implications of immigration.
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Affiliation(s)
- Jane M Reid
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Lisa Dickel
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Lukas F Keller
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
- Natural History Museum, University of Zurich, Zurich, Switzerland
| | - Pirmin Nietlisbach
- School of Biological Sciences, Illinois State University, Normal, Illinois, USA
| | - Peter Arcese
- Department of Forest & Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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9
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Knape J, Paquet M, Arlt D, Kačergytė I, Pärt T. Partitioning variance in population growth for models with environmental and demographic stochasticity. J Anim Ecol 2023; 92:1979-1991. [PMID: 37491892 DOI: 10.1111/1365-2656.13990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/04/2023] [Indexed: 07/27/2023]
Abstract
How demographic factors lead to variation or change in growth rates can be investigated using life table response experiments (LTRE) based on structured population models. Traditionally, LTREs focused on decomposing the asymptotic growth rate, but more recently decompositions of annual 'realized' growth rates using 'transient' LTREs have gained in popularity. Transient LTREs have been used particularly to understand how variation in vital rates translate into variation in growth for populations under long-term study. For these, complete population models may be constructed to investigate how temporal variation in environmental drivers affect vital rates. Such investigations have usually come down to estimating covariate coefficients for the effects of environmental variables on vital rates, but formal ways of assessing how they lead to variation in growth rates have been lacking. We extend transient LTREs to further partition the contributions from vital rates into contributions from temporally varying factors that affect them. The decomposition allows one to compare the resultant effect on the growth rate of different environmental factors, as well as density dependence, which may each act via multiple vital rates. We also show how realized growth rates can be decomposed into separate components from environmental and demographic stochasticity. The latter is typically omitted in LTRE analyses. We illustrate these extensions with an integrated population model (IPM) for data from a 26 years study on northern wheatears (Oenanthe oenanthe), a migratory passerine bird breeding in an agricultural landscape. For this population, consisting of around 50-120 breeding pairs per year, we partition variation in realized growth rates into environmental contributions from temperature, rainfall, population density and unexplained random variation via multiple vital rates, and from demographic stochasticity. The case study suggests that variation in first year survival via the unexplained random component, and adult survival via temperature are two main factors behind environmental variation in growth rates. More than half of the variation in growth rates is suggested to come from demographic stochasticity, demonstrating the importance of this factor for populations of moderate size.
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Affiliation(s)
- Jonas Knape
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Matthieu Paquet
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- Institute of Mathematics of Bordeaux, University of Bordeaux, CNRS, Bordeaux INP, Talence, France
| | - Debora Arlt
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- SLU Swedish Species Information Centre, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Ineta Kačergytė
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Tomas Pärt
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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10
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Lehtinen RM. Empirical Evidence for the Rescue Effect from a Natural Microcosm. Animals (Basel) 2023; 13:1907. [PMID: 37370418 DOI: 10.3390/ani13121907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/27/2023] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
Ecological theory predicts that populations which receive immigrants are less vulnerable to extinction than those that do not receive immigrants (the "rescue effect"). A parallel but opposite process may also exist, where emigration increases the risk of local extinction (the "abandon-ship effect"). Using a natural microcosm of plant-specialist frogs from Madagascar, empirical evidence for both processes is provided. Populations receiving immigrants were less extinction-prone than those without immigration, and those populations losing individuals through emigration were more extinction-prone than those in which no emigration occurred. The number of immigrants and emigrants was also elevated and depressed (respectively) in patches that did not go extinct. These data provide some of the first definitive empirical evidence for the rescue effect and provide suggestive initial data on the abandon-ship effect. Both of these processes may be important to understanding the dynamics of populations.
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Affiliation(s)
- Richard M Lehtinen
- Division of Reptiles and Amphibians, University of Michigan Museum of Zoology, Ann Arbor, MI 48109, USA
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11
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Tenan S, Moulins A, Tepsich P, Bocconcelli A, Verga A, Ballardini M, Nani B, Papi D, Motta G, Aguilar AS, Rosso M. Immigration as the main driver of population dynamics in a cryptic cetacean. Ecol Evol 2023; 13:e9806. [PMID: 36789337 PMCID: PMC9919498 DOI: 10.1002/ece3.9806] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 11/28/2022] [Accepted: 01/16/2023] [Indexed: 02/13/2023] Open
Abstract
Empirical evidence about the role and interaction of immigration with local demographic processes in shaping population dynamics is still scarce. This knowledge gap limits our capability to derive a conceptual framework that can be used to inform conservation actions. Populations exposed to nonstationary environment do not converge to a stable stage distribution, implying the need for evaluating the demographic role of both vital rates and stage distribution using appropriate tools. This is particularly important for species with larger generation times like cetaceans. We explored the relative demographic role of vital rates and population structure of a poorly known cetacean, the Mediterranean Cuvier's beaked whale, while accounting for the exposure to nonstationary environments. We performed a retrospective analysis through transient life table response experiments (tLTRE) using demographic rates and population structure of both sexes obtained from an integrated population model. The contribution of immigration to variation in realized population growth rates was 4.2, 7.6, and 12.7 times larger than that of female apparent survival, proportional abundance of breeding females with a 2-year-old calf, and proportional abundance of breeding females with a 3-year-old calf, respectively. Immigration rate and proportional abundance of breeding females with a 2- or 3-year-old calf explained, respectively, 65% and 20% of total temporal variability in realized population growth rates. Changes in realized population growth rate between successive years were mainly driven by changes in immigration and population structure, specifically the proportional abundance of breeding females with a 2-year-old calf. Our study provides insight into the demographic processes that affect population dynamics and in a cryptic cetacean. We presented an analytical approach for maximizing the use of available data through the integration of multiple sources of information for individuals of different distinctiveness levels.
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Affiliation(s)
- Simone Tenan
- Institute of Marine Sciences (CNR‐ISMAR)National Research CouncilVeneziaItaly
| | | | | | - Alessandro Bocconcelli
- Advanced Ocean Physics EngineeringWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | | | | | | | | | | | - Ana Sanz Aguilar
- Animal Demography and Ecology Unit, GEDA ‐ IMEDEA (CSIC‐UIB)EsporlesSpain,Applied Zoology and Conservation GroupUniversity of the Balearic IslandsPalmaSpain
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12
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Fandos G, Talluto M, Fiedler W, Robinson RA, Thorup K, Zurell D. Standardised empirical dispersal kernels emphasise the pervasiveness of long-distance dispersal in European birds. J Anim Ecol 2023; 92:158-170. [PMID: 36398379 DOI: 10.1111/1365-2656.13838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Accepted: 10/01/2022] [Indexed: 11/19/2022]
Abstract
Dispersal is a key life-history trait for most species and is essential to ensure connectivity and gene flow between populations and facilitate population viability in variable environments. Despite the increasing importance of range shifts due to global change, dispersal has proved difficult to quantify, limiting empirical understanding of this phenotypic trait and wider synthesis. Here, we introduce a statistical framework to estimate standardised dispersal kernels from biased data. Based on this, we compare empirical dispersal kernels for European breeding birds considering age (average dispersal; natal, before first breeding; and breeding dispersal, between subsequent breeding attempts) and sex (females and males) and test whether different dispersal properties are phylogenetically conserved. We standardised and analysed data from an extensive volunteer-based bird ring-recoveries database in Europe (EURING) by accounting for biases related to different censoring thresholds in reporting between countries and to migratory movements. Then, we fitted four widely used probability density functions in a Bayesian framework to compare and provide the best statistical descriptions of the different age and sex-specific dispersal kernels for each bird species. The dispersal movements of the 234 European bird species analysed were statistically best explained by heavy-tailed kernels, meaning that while most individuals disperse over short distances, long-distance dispersal is a prevalent phenomenon in almost all bird species. The phylogenetic signal in both median and long dispersal distances estimated from the best-fitted kernel was low (Pagel's λ < 0.25), while it reached high values (Pagel's λ >0.7) when comparing dispersal distance estimates for fat-tailed dispersal kernels. As expected in birds, natal dispersal was on average 5 km greater than breeding dispersal, but sex-biased dispersal was not detected. Our robust analytical framework allows sound use of widely available mark-recapture data in standardised dispersal estimates. We found strong evidence that long-distance dispersal is common among European breeding bird species and across life stages. The dispersal estimates offer a first guide to selecting appropriate dispersal kernels in range expansion studies and provide new avenues to improve our understanding of the mechanisms and rules underlying dispersal events.
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Affiliation(s)
- Guillermo Fandos
- Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Geography Department, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Matthew Talluto
- Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Wolfgang Fiedler
- Department of Biology, Max Planck Institute of Animal Behavior, University of Konstanz, Radolfzell, Germany
| | - Robert A Robinson
- British Trust for Ornithology, Thetford, Norfolk, UK.,European Union for Bird Ringing c/o British Trust for Ornithology, Norfolk, UK
| | - Kasper Thorup
- Center for Macroecology, Evolution and Climate, Globe Institute, University of Copenhagen, Copenhagen, Denmark.,Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Damaris Zurell
- Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany.,Geography Department, Humboldt-Universität zu Berlin, Berlin, Germany
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13
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Sinnott EA, Thompson FR, Weegman MD, Thompson TR, Mosloff AR, Hedges RK, Loncarich FL. Evaluation of seasonal site-level demography and management for northern bobwhite using integrated population models. Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2022.110211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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14
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Nater CR, Burgess MD, Coffey P, Harris B, Lander F, Price D, Reed M, Robinson RA. Spatial consistency in drivers of population dynamics of a declining migratory bird. J Anim Ecol 2023; 92:97-111. [PMID: 36321197 PMCID: PMC10099983 DOI: 10.1111/1365-2656.13834] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 10/13/2022] [Indexed: 11/17/2022]
Abstract
Many migratory species are in decline across their geographical ranges. Single-population studies can provide important insights into drivers at a local scale, but effective conservation requires multi-population perspectives. This is challenging because relevant data are often hard to consolidate, and state-of-the-art analytical tools are typically tailored to specific datasets. We capitalized on a recent data harmonization initiative (SPI-Birds) and linked it to a generalized modelling framework to identify the demographic and environmental drivers of large-scale population decline in migratory pied flycatchers (Ficedula hypoleuca) breeding across Britain. We implemented a generalized integrated population model (IPM) to estimate age-specific vital rates, including their dependency on environmental conditions, and total and breeding population size of pied flycatchers using long-term (34-64 years) monitoring data from seven locations representative of the British breeding range. We then quantified the relative contributions of different vital rates and population structure to changes in short- and long-term population growth rate using transient life table response experiments (LTREs). Substantial covariation in population sizes across breeding locations suggested that change was the result of large-scale drivers. This was supported by LTRE analyses, which attributed past changes in short-term population growth rates and long-term population trends primarily to variation in annual survival and dispersal dynamics, which largely act during migration and/or nonbreeding season. Contributions of variation in local reproductive parameters were small in comparison, despite sensitivity to local temperature and rainfall within the breeding period. We show that both short- and long-term population changes of British breeding pied flycatchers are likely linked to factors acting during migration and in nonbreeding areas, where future research should be prioritized. We illustrate the potential of multi-population analyses for informing management at (inter)national scales and highlight the importance of data standardization, generalized and accessible analytical tools, and reproducible workflows to achieve them.
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Affiliation(s)
- Chloé R Nater
- Norwegian Institute for Nature Research (NINA), Trondheim, Norway.,Centre for Biodiversity Dynamics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Malcolm D Burgess
- RSPB Centre for Conservation Science, Sandy, UK.,PiedFly.Net, Yarner Wood, Devon, UK.,Centre for Research in Animal Behaviour, University of Exeter, Exeter, UK
| | | | - Bob Harris
- Merseyside Ringing Group, Merseyside, UK
| | - Frank Lander
- PiedFly.Net, Yarner Wood, Devon, UK.,Forest of Dean, Gloucestershire, UK
| | | | - Mike Reed
- 143 Daniells Welwyn Garden City, Hertfordshire, UK
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15
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Juhasz CC, Avargues N, Humeau L, Ringler D, Pinet P, Hollinger C, Beaulieu R, Faulquier L, Choeur A, Bureau S, Da Silva D, Dubos J, Soulaimana-Mattoir Y, Le Corre M. Application of genetic and Spatially Explicit Capture-Recapture analyses to design adaptive feral cat control in a large inhabited island. NEOBIOTA 2022. [DOI: 10.3897/neobiota.79.87726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Faunas of oceanic islands have a high proportion of endemic species which contribute to the uniqueness of island communities. Island species are particularly naïve and vulnerable to alien predators, such as cats (Felis catus). On large, inhabited islands, where the complete eradication of feral cat populations is not considered feasible, control represents the best management option to lower their detrimental effects on native fauna. The first objective of our study was to investigate population genetics of feral cats of Réunion Island. The second objective was to understand the space use of feral cats established near the breeding colonies of the two endemic and endangered seabirds of Réunion Island, the Barau’s Petrel (Pterodroma baraui) and the Mascarene Petrel (Pseudobulweria aterrima). We evaluated genetic diversity, population structure and gene flow amongst six groups of feral cats located at a maximum of 10 km from known petrel colonies. We also analysed the behaviour and space use of one of these feral cat groups using camera-trap data and Spatially Explicit Capture-Recapture (SECR) models. Genetic analyses revealed that feral cats were structured in three genetic clusters explained mostly by the island topography. Two clusters were observed at five sampled sites, suggesting high connectivity amongst these sites. The last cluster was found in only one site, suggesting high isolation. This site was a remote mountain area located in the vicinity of one of the main Barau’s Petrel colonies. The behavioural study was conducted on this isolated feral cat population. Mark recapture analysis suggested that feral cats were present at low density and had large home ranges, which is probably explained by reduced food availability. Finally, we make several recommendations for refining feral cat management programmes on inhabited islands.
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16
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Kohl PL, Rutschmann B, Steffan-Dewenter I. Population demography of feral honeybee colonies in central European forests. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220565. [PMID: 35950195 PMCID: PMC9346370 DOI: 10.1098/rsos.220565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 07/13/2022] [Indexed: 06/15/2023]
Abstract
European honeybee populations are considered to consist only of managed colonies, but recent censuses have revealed that wild/feral colonies still occur in various countries. To gauge the ecological and evolutionary relevance of wild-living honeybees, information is needed on their population demography. We monitored feral honeybee colonies in German forests for up to 4 years through regular inspections of woodpecker cavity trees and microsatellite genotyping. Each summer, about 10% of the trees were occupied, corresponding to average densities of 0.23 feral colonies km-2 (an estimated 5% of the regional honeybee populations). Populations decreased moderately until autumn but dropped massively during winter, so that their densities were only about 0.02 colonies km-2 in early spring. During the reproductive (swarming) season, in May and June, populations recovered, with new swarms preferring nest sites that had been occupied in the previous year. The annual survival rate and the estimated lifespan of feral colonies (n = 112) were 10.6% and 0.6 years, respectively. We conclude that managed forests in Germany do not harbour self-sustaining feral honeybee populations, but they are recolonized every year by swarms escaping from apiaries.
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Affiliation(s)
- Patrick L. Kohl
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Benjamin Rutschmann
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Ingolf Steffan-Dewenter
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
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17
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Zub K, García-Díaz P, Sankey S, Eisler R, Lambin X. Using a Modeling Approach to Inform Progress Towards Stoat Eradication From the Orkney Islands. FRONTIERS IN CONSERVATION SCIENCE 2022. [DOI: 10.3389/fcosc.2021.780102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Invasive non-native species eradication attempts are typically large and expensive projects that benefit from the support of quantitative tools, such as population models, to be completed within the scheduled and funded time. Managed ecosystems are constantly changing due to population and ecosystem dynamics. Accordingly, any model predictions need to be updated, using different sources of data, to inform the project about the progress toward eradication. The stoat Mustela erminea was introduced to the hitherto predatory land mammal free Orkney archipelago around 2010. In 2016, a project aiming to eradicate stoats to preserve ecologically and economically important native wildlife was designed and implemented. It entailed a “knockdown” phase followed by a “mopping-up” phase to remove stoats that escaped capture. We used data from this project to iteratively predict the progress toward eradication. We applied spatially explicit individual-based models to estimate the proportion of stoats being exposed to capture, and then compared these simulation-based predictions with removal data, allowing us to estimate changes in the population size through time. We also used sighting data from members of the public to refine eradication probability. We were also able to demonstrate how the initially wide uncertainty gradually diminished as more evidence accumulated. The information derived from different types of data and quantitative models allowed us to track the effectiveness of current trapping approaches and to help to inform project managers about when the project achieved the knockdown phase milestone. Our analyses confirmed that the expected magnitude of the initial knockdown phase has been achieved in some areas, but also revealed spatial and temporal heterogeneity in the distribution of captures, most likely caused by the sequential trapping and stoat movement and trap shy stoats exposed to capture but not caught. This heterogeneity calls for additional data sources (e.g., from camera traps or detection dogs) to estimate the proportion of trap-shy individuals and the size of the untrapped population, and ultimately the feasibility of eradication.
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18
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Barras AG, Blache S, Schaub M, Arlettaz R. Variation in Demography and Life-History Strategies Across the Range of a Declining Mountain Bird Species. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.780706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Species- and population-specific responses to their environment may depend to a large extent on the spatial variation in life-history traits and in demographic processes of local population dynamics. Yet, those parameters and their variability remain largely unknown for many cold-adapted species, which are exposed to particularly rapid rates of environmental change. Here, we compared the demographic traits and dynamics for an emblematic bird species of European mountain ecosystems, the ring ouzel (Turdus torquatus). Using integrated population models fitted in a Bayesian framework, we estimated the survival probability, productivity and immigration of two populations from the Western European Alps, in France (over 11 years) and Switzerland (over 6 years). Juvenile apparent survival was lower and immigration rate higher in the Swiss compared to the French population, with the temporal variation in population growth rate driven by different demographic processes. Yet, when compared to populations in the northwestern part of the range, in Scotland, these two Alpine populations both showed a much lower productivity and higher adult survival, indicating a slower life-history strategy. Our results suggest that demographic characteristics can substantially vary across the discontinuous range of this passerine species, essentially due to contrasted, possibly locally evolved life-history strategies. This study therefore raises the question of whether flexibility in life-history traits is widespread among boreo-alpine species and if it might provide adaptive potential for coping with current environmental change.
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19
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Ranke PS, Araya-Ajoy YG, Ringsby TH, Pärn H, Rønning B, Jensen H, Wright J, Saether BE. Spatial structure and dispersal dynamics in a house sparrow metapopulation. J Anim Ecol 2021; 90:2767-2781. [PMID: 34455579 DOI: 10.1111/1365-2656.13580] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 08/13/2021] [Indexed: 11/29/2022]
Abstract
The effects of spatial structure on metapopulation dynamics depend upon the interaction between local population dynamics and dispersal, and how this relationship is affected by the geographical isolation and spatial heterogeneity in habitat characteristics. Our aim is to examine how emigration and immigration of house sparrows Passer domesticus in a Norwegian archipelagic metapopulation are affected by key factors predicted by classic metapopulation models to affect dispersal-spatial and temporal variation in population size, inter-island distance, local demography and habitat characteristics. This metapopulation can be divided into two major habitat types: (a) islands closer to the mainland where sparrows breed in colonies on farms, and (b) islands without farms, situated farther away from the mainland where sparrows are exposed to harsher environmental conditions. Dispersal was spatially structured within the metapopulation; there was proportionally and numerically less emigration and immigration involving farm islands, as compared to non-farm islands. Furthermore, emigration and immigration occurred mostly between nearby islands. Moreover, emigration in response to spatial differences in mean population size differed between the habitat types, but populations with large mean received more immigrants in both habitat types. The number of emigrants and immigrants was negatively related to long-term recruit production, which was not the case in non-farm islands. The proportion and number of emigrants was positively related to temporal increases in recruit production on farm islands, however not on non-farm islands. Our results demonstrate that spatial heterogeneity in environmental conditions influences how spatial variation in long-term mean population size, and temporal and spatial variation in recruit production, affects dispersal dynamics. The spatial structure of this metapopulation is therefore best described by a spatially explicit model in which the exchange of individuals within each habitat type is strongly affected by the degree of geographical isolation, population size and recruit production. However, these relationships differed between the two habitat types; non-farm islands showing similarities to a mainland-island model type of structure, whereas farm islands showed features more associated with source-sink or balanced dispersal models. Such differential dispersal dynamics between habitat types are expected to have important consequences for the ecological and evolutionary dynamics within this metapopulation.
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Affiliation(s)
- Peter S Ranke
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Yimen G Araya-Ajoy
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Thor Harald Ringsby
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Henrik Pärn
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Bernt Rønning
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Henrik Jensen
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jonathan Wright
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Bernt-Erik Saether
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
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20
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Paquet M, Knape J, Arlt D, Forslund P, Pärt T, Flagstad Ø, Jones CG, Nicoll MAC, Norris K, Pemberton JM, Sand H, Svensson L, Tatayah V, Wabakken P, Wikenros C, Åkesson M, Low M. Integrated population models poorly estimate the demographic contribution of immigration. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13667] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthieu Paquet
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Jonas Knape
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Debora Arlt
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
- SLU Swedish Species Information Centre Swedish University of Agricultural Sciences Uppsala Sweden
| | - Pär Forslund
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Tomas Pärt
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | | | - Carl G. Jones
- Mauritian Wildlife Foundation Vacoas Mauritius
- Durrell Wildlife Conservation Trust Trinity UK
| | | | | | - Josephine M. Pemberton
- Institute of Evolutionary Biology School of Biological Sciences University of Edinburgh Edinburgh UK
| | - Håkan Sand
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Linn Svensson
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | | | - Petter Wabakken
- Faculty of Applied Ecology and Agricultural Sciences Inland Norway University of Applied Sciences Hamar Norway
| | - Camilla Wikenros
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Mikael Åkesson
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
| | - Matthew Low
- Department of Ecology Swedish University of Agricultural Sciences Uppsala Sweden
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21
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Saatoglu D, Niskanen AK, Kuismin M, Ranke PS, Hagen IJ, Araya-Ajoy YG, Kvalnes T, Pärn H, Rønning B, Ringsby TH, Saether BE, Husby A, Sillanpää MJ, Jensen H. Dispersal in a house sparrow metapopulation: An integrative case study of genetic assignment calibrated with ecological data and pedigree information. Mol Ecol 2021; 30:4740-4756. [PMID: 34270821 DOI: 10.1111/mec.16083] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 07/02/2021] [Accepted: 07/05/2021] [Indexed: 01/12/2023]
Abstract
Dispersal has a crucial role determining ecoevolutionary dynamics through both gene flow and population size regulation. However, to study dispersal and its consequences, one must distinguish immigrants from residents. Dispersers can be identified using telemetry, capture-mark-recapture (CMR) methods, or genetic assignment methods. All of these methods have disadvantages, such as high costs and substantial field efforts needed for telemetry and CMR surveys, and adequate genetic distance required in genetic assignment. In this study, we used genome-wide 200K Single Nucleotide Polymorphism data and two different genetic assignment approaches (GSI_SIM, Bayesian framework; BONE, network-based estimation) to identify the dispersers in a house sparrow (Passer domesticus) metapopulation sampled over 16 years. Our results showed higher assignment accuracy with BONE. Hence, we proceeded to diagnose potential sources of errors in the assignment results from the BONE method due to variation in levels of interpopulation genetic differentiation, intrapopulation genetic variation and sample size. We show that assignment accuracy is high even at low levels of genetic differentiation and that it increases with the proportion of a population that has been sampled. Finally, we highlight that dispersal studies integrating both ecological and genetic data provide robust assessments of the dispersal patterns in natural populations.
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Affiliation(s)
- Dilan Saatoglu
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Alina K Niskanen
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.,Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
| | - Markku Kuismin
- Research Unit of Mathematical Sciences, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Finland
| | - Peter S Ranke
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ingerid J Hagen
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.,Norwegian Institute for Nature Research, Trondheim, Norway
| | - Yimen G Araya-Ajoy
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Thomas Kvalnes
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Henrik Pärn
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Bernt Rønning
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Thor Harald Ringsby
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Bernt-Erik Saether
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Arild Husby
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Mikko J Sillanpää
- Research Unit of Mathematical Sciences, University of Oulu, Oulu, Finland.,Biocenter Oulu, University of Oulu, Finland.,Infotech Oulu, University of Oulu, Oulu, Finland
| | - Henrik Jensen
- Centre for Biodiversity Dynamics, Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
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22
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Nater CR, Eide NE, Pedersen ÅØ, Yoccoz NG, Fuglei E. Contributions from terrestrial and marine resources stabilize predator populations in a rapidly changing climate. Ecosphere 2021. [DOI: 10.1002/ecs2.3546] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Chloé R. Nater
- Norwegian Polar Institute Tromsø Norway
- Centre for Biodiversity Dynamics Norwegian University of Science and Technology Trondheim Norway
- Department of Arctic and Marine Biology UIT – The Arctic University of Norway Tromsø Norway
| | - Nina E. Eide
- Norwegian Institute for Nature Research Trondheim Norway
| | | | - Nigel G. Yoccoz
- Department of Arctic and Marine Biology UIT – The Arctic University of Norway Tromsø Norway
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23
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Rushing CS, Brandt Ryder T, Valente JJ, Scott Sillett T, Marra PP. Empirical tests of habitat selection theory reveal that conspecific density and patch quality, but not habitat amount, drive long-distance immigration in a wild bird. Ecol Lett 2021; 24:1167-1177. [PMID: 33742759 PMCID: PMC8251823 DOI: 10.1111/ele.13729] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/21/2020] [Accepted: 02/13/2021] [Indexed: 11/30/2022]
Abstract
Individuals that disperse long distances from their natal site must select breeding patches with no prior knowledge of patch suitability. Despite decades of theoretical studies examining which cues dispersing individuals should use to select breeding patches, few empirical studies have tested the predictions of these theories at spatial scales relevant to long‐distance dispersal in wild animal populations. Here, we use a novel assignment model based on multiple intrinsic markers to quantify natal dispersal distances of Wood Thrush (Hylocichla mustelina) breeding in forest fragments. We show that long‐distance natal dispersal in this species is more frequent than commonly assumed for songbirds and that habitat selection by these individuals is driven by density‐dependence and patch quality but not the amount of habitat surrounding breeding patches. These results represent an important contribution to understanding habitat selection by dispersing individuals, especially with regards to long‐distance dispersal.
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Affiliation(s)
- Clark S Rushing
- Department of Wildland Resources and the Ecology Center, Utah State University, 5230 Old Main Hill, Logan, UT, 84322, USA.,Smithsonian Migratory Bird Center, National Zoological Park, Washington, DC, 20013, USA
| | - T Brandt Ryder
- Smithsonian Migratory Bird Center, National Zoological Park, Washington, DC, 20013, USA.,Bird Conservancy of the Rockies, Fort Collins, CO, 80525, USA
| | - Jonathon J Valente
- Smithsonian Migratory Bird Center, National Zoological Park, Washington, DC, 20013, USA.,Department of Forest Engineering, Resources, and Management, Oregon State University, Corvallis, OR, 97331, USA
| | - T Scott Sillett
- Smithsonian Migratory Bird Center, National Zoological Park, Washington, DC, 20013, USA
| | - Peter P Marra
- Smithsonian Migratory Bird Center, National Zoological Park, Washington, DC, 20013, USA.,Department of Biology and McCourt School of Public Policy, Georgetown University, 37th and O Streets, NW, Washington, DC, 20057, USA
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24
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Phenotypic and environmental correlates of natal dispersal in a long-lived territorial vulture. Sci Rep 2021; 11:5424. [PMID: 33686130 PMCID: PMC7970891 DOI: 10.1038/s41598-021-84811-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 02/12/2021] [Indexed: 01/31/2023] Open
Abstract
Natal dispersal, the movement between the birth and the first breeding site, has been rarely studied in long-lived territorial birds with a long-lasting pre-breeding stage. Here we benefited from the long-term monitoring programs of six populations of Egyptian vultures (Neophron percnopterus) from Spain and France to study how the rearing environment determines dispersal. For 124 vultures, we recorded a median dispersal distance of 48 km (range 0-656 km). Linear models were used to assess the effect of population and individual traits on dispersal distance at two spatial scales. Dispersal distances were inversely related to vulture density in the natal population, suggesting that birds perceive the abundance of conspecifics as a signal of habitat quality. This was particularly true for declining populations, so increasing levels of opportunistic philopatry seemed to arise in high density contexts as a consequence of vacancies created by human-induced adult mortality. Females dispersed further than males, but males were more sensitive to the social environment, indicating different dispersal tactics. Both sexes were affected by different individual attributes simultaneously and interactively with this social context. These results highlight that complex phenotype-by-environment interactions should be considered for advancing our understanding of dispersal dynamics in long-lived organisms.
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25
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Palmas P, Gouyet R, Oedin M, Millon A, Cassan JJ, Kowi J, Bonnaud E, Vidal E. Rapid recolonisation of feral cats following intensive culling in a semi-isolated context. NEOBIOTA 2020. [DOI: 10.3897/neobiota.63.58005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Invasive feral cats threaten biodiversity at a global scale. Mitigating feral cat impacts and reducing their populations has therefore become a global conservation priority, especially on islands housing high endemic biodiversity. The New Caledonian archipelago is a biodiversity hotspot showing outstanding terrestrial species richness and endemism. Feral cats prey upon at least 44 of its native vertebrate species, 20 of which are IUCN Red-listed threatened species. To test the feasibility and efficiency of culling, intensive culling was conducted in a peninsula of New Caledonia (25.6 km²) identified as a priority site for feral cat management. Live-trapping over 38 days on a 10.6 km² area extirpated 36 adult cats, an estimated 44% of the population. However, three months after culling, all indicators derived from camera-trapping (e.g., abundance, minimum number of individuals and densities) suggest a return to pre-culling levels. Compensatory immigration appears to explain this unexpectedly rapid population recovery in a semi-isolated context. Since culling success does not guarantee a long-term effect, complementary methods like fencing and innovative automated traps need to be used, in accordance with predation thresholds identified through modelling, to preserve island biodiversity. Testing general assumptions on cat management, this article contributes important insights into a challenging conservation issue for islands and biodiversity hotspots worldwide.
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26
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Reichert BE, Fletcher RJ, Kitchens WM. The demographic contributions of connectivity versus local dynamics to population growth of an endangered bird. J Anim Ecol 2020; 90:574-584. [PMID: 33179773 DOI: 10.1111/1365-2656.13387] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 10/07/2020] [Indexed: 11/30/2022]
Abstract
Conservation and management increasingly focus on connectivity, because connectivity driven by variation in immigration rates across landscapes is thought to be crucial for maintaining local population and metapopulation persistence. Yet, efforts to quantify the relative role of immigration on population growth across the entire range of species and over time have been lacking. We assessed whether immigration limited local and range-wide population growth of the endangered snail kite Rostrhamus sociabilis in Florida, USA, over 18 years using multi-state, reverse-time modelling that accounts for imperfect detection of individuals and unobservable states. Demographic contributions of immigration varied depending on the dynamics and geographic position of the local populations, were scale-dependent and changed over time. By comparing the relative contributions of immigration versus local demography for periods of significant change in local abundance, we found empirical evidence for a disproportionately large role of immigration in facilitating population growth of a centrally located population-a connectivity 'hub'. The importance of connectivity changed depending of the spatial scale considered, such that immigration was a more important driver of population growth at small versus large spatial scales. Furthermore, the contribution of immigration was much greater during time periods when local population size was small, emphasizing abundance-dependent rescue effects. Our findings suggest that efforts aimed at improving local breeding habitat will likely be most effective at increasing snail kite population growth. More broadly, our results provide much needed information on the role of connectivity for population growth, suggesting that connectivity conservation may have the greatest benefits when efforts focus on centrally located habitat patches and small populations. Furthermore, our results highlight that connectivity is highly dynamic over time and that interpreting the effects of connectivity at local scales may not transfer to region-wide dynamics.
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Affiliation(s)
- Brian E Reichert
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | - Robert J Fletcher
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
| | - Wiley M Kitchens
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, USA
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27
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Yeiser JM, Jackson AL, Sisson DC, Terhune TM, Martin JA. Predation Management and Spatial Structure Moderate Extirpation Risk and Harvest of Northern Bobwhite. J Wildl Manage 2020. [DOI: 10.1002/jwmg.21964] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- John M. Yeiser
- D. B. Warnell School of Forestry and Natural Resources University of Georgia Athens GA 30602 USA
| | - Alexander L. Jackson
- D. B. Warnell School of Forestry and Natural Resources University of Georgia Athens GA 30602 USA
| | - D. Clay Sisson
- Tall Timbers, Albany Quail Project 5765 Pigeon Road Newton GA 39870 USA
| | | | - James A. Martin
- D. B. Warnell School of Forestry and Natural Resources University of Georgia Athens GA 30602 USA
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Paquet M, Arlt D, Knape J, Low M, Forslund P, Pärt T. Why we should care about movements: Using spatially explicit integrated population models to assess habitat source-sink dynamics. J Anim Ecol 2020; 89:2922-2933. [PMID: 32981078 PMCID: PMC7756878 DOI: 10.1111/1365-2656.13357] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 08/31/2020] [Indexed: 11/30/2022]
Abstract
Assessing the source–sink status of populations and habitats is of major importance for understanding population dynamics and for the management of natural populations. Sources produce a net surplus of individuals (per capita contribution to the metapopulation > 1) and will be the main contributors for self‐sustaining populations, whereas sinks produce a deficit (contribution < 1). However, making these types of assessments is generally hindered by the problem of separating mortality from permanent emigration, especially when survival probabilities as well as moved distances are habitat‐specific. To address this long‐standing issue, we propose a spatial multi‐event integrated population model (IPM) that incorporates habitat‐specific dispersal distances of individuals. Using information about local movements, this IPM adjusts survival estimates for emigration outside the study area. Analysing 24 years of data on a farmland passerine (the northern wheatear Oenanthe oenanthe), we assessed habitat‐specific contributions, and hence the source–sink status and temporal variation of two key breeding habitats, while accounting for habitat‐ and sex‐specific local dispersal distances of juveniles and adults. We then examined the sensitivity of the source–sink analysis by comparing results with and without accounting for these local movements. Estimates of first‐year survival, and consequently habitat‐specific contributions, were higher when local movement data were included. The consequences from including movement data were sex specific, with contribution shifting from sink to likely source in one habitat for males, and previously noted habitat differences for females disappearing. Assessing the source–sink status of habitats is extremely challenging. We show that our spatial IPM accounting for local movements can reduce biases in estimates of the contribution by different habitats, and thus reduce the overestimation of the occurrence of sink habitats. This approach allows combining all available data on demographic rates and movements, which will allow better assessment of source–sink dynamics and better informed conservation interventions.
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Affiliation(s)
- Matthieu Paquet
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Debora Arlt
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.,SLU Swedish Species Information Centre, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Jonas Knape
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Matthew Low
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Pär Forslund
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Tomas Pärt
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Schaub M, Ullrich B. A drop in immigration results in the extinction of a local woodchat shrike population. Anim Conserv 2020. [DOI: 10.1111/acv.12639] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- M. Schaub
- Swiss Ornithological Institute Sempach Switzerland
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Abstract
Abstract
The critical agenda for mammalian ecologists over this century is to obtain a synthetic and predictive understanding of the factors that limit the distribution and abundance of mammals on Earth. During the last 100 years, a start has been made on this agenda, but only a start. Most mammal species have been described, but there still are tropical areas of undisclosed species richness. We have been measuring changes in distribution and abundance of many common mammals during the last century, and this monitoring agenda has become more critical as climate change has accelerated and habitat destruction has increased with human population growth. There are a small number of factors that can limit the distribution and abundance of mammals: weather, predation, food supplies, disease, and social behavior. Weather limits distribution and abundance mostly in an indirect manner by affecting food supplies, disease, and predation in the short term and habitat composition and structure in the longer term. A good starting point for all studies of mammals is to define them within a well-structured trophic web, and then quantify the major linkages within that web. We still are far from having data on enough model systems to develop a complete theory and understanding of how food webs are structured and constrained as climate shifts and humans disturb habitats. We have many of the bits and pieces for some of our major ecosystems but a poor understanding of the links and the resilience of our mammalian communities to changes in trophic webs driven by climate change and human disturbances.
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Affiliation(s)
- Charles J Krebs
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
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