1
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Marucco F, Boiani MV, Dupont P, Milleret C, Avanzinelli E, Pilgrim K, Schwartz MK, von Hardenberg A, Perrone DS, Friard OP, Menzano A, Bisi F, Fattori U, Tomasella M, Calderola S, Carolfi S, Ferrari P, Chioso C, Truc F, Bombieri G, Pedrotti L, Righetti D, Acutis PL, Guglielmo F, Hauffe HC, Rossi C, Caniglia R, Aragno P, La Morgia V, Genovesi P, Bischof R. A multidisciplinary approach to estimating wolf population size for long-term conservation. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2023; 37:e14132. [PMID: 37259636 DOI: 10.1111/cobi.14132] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 02/06/2023] [Accepted: 05/23/2023] [Indexed: 06/02/2023]
Abstract
The wolf (Canis lupus) is among the most controversial of wildlife species. Abundance estimates are required to inform public debate and policy decisions, but obtaining them at biologically relevant scales is challenging. We developed a system for comprehensive population estimation across the Italian alpine region (100,000 km2 ), involving 1513 trained operators representing 160 institutions. This extensive network allowed for coordinated genetic sample collection and landscape-level spatial capture-recapture analyses that transcended administrative boundaries to produce the first estimates of key parameters for wolf population status assessment. Wolf abundance was estimated at 952 individuals (95% credible interval 816-1120) and 135 reproductive units (i.e., packs) (95% credible interval 112-165). We also estimated that mature individuals accounted for 33-45% of the entire population. The monitoring effort was spatially estimated thereby overcoming an important limitation of citizen science data. This is an important approach for promoting wolf-human coexistence based on wolf abundance monitoring and an endorsement of large-scale harmonized conservation practices.
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Affiliation(s)
- Francesca Marucco
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Maria V Boiani
- Department of Biological Sciences, Conservation Biology Research Group, University of Chester, Chester, UK
| | - Pierre Dupont
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Cyril Milleret
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Elisa Avanzinelli
- Centro Grandi Carnivori, Ente di Gestione Aree Protette Alpi Marittime, Valdieri, Italy
| | - Kristine Pilgrim
- USDA National Genomics Center for Wildlife and Fish Conservation, Missoula, Montana, USA
| | - Michael K Schwartz
- USDA National Genomics Center for Wildlife and Fish Conservation, Missoula, Montana, USA
| | - Achaz von Hardenberg
- Department of Biological Sciences, Conservation Biology Research Group, University of Chester, Chester, UK
| | | | - Olivier P Friard
- Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
| | - Arianna Menzano
- Centro Grandi Carnivori, Ente di Gestione Aree Protette Alpi Marittime, Valdieri, Italy
| | - Francesco Bisi
- Environmental Analysis and Management Unit, Guido Tosi Research Group, Department of Theoretical and Applied Sciences, University of Insubria, Varese, Italy
| | - Umberto Fattori
- Regione Autonoma Friuli Venezia Giulia, Osservatorio Biodiversità, Trieste, Italy
| | - Michela Tomasella
- Regione Autonoma Friuli Venezia Giulia, Osservatorio Biodiversità, Trieste, Italy
| | - Sonia Calderola
- Regione del Veneto, Direzione Agroambiente, Programmazione e Gestione ittica e faunistico-venatoria, Venezia, Italy
| | - Sabrina Carolfi
- Regione Liguria, Settore Politiche della Natura e delle aree Interne, Protette e Marine, Parchi e Biodiversità - Settore Fauna Selvatica, Caccia e Vigilanza Venatoria, Genoa, Italy
| | - Piero Ferrari
- Regione Liguria, Settore Politiche della Natura e delle aree Interne, Protette e Marine, Parchi e Biodiversità - Settore Fauna Selvatica, Caccia e Vigilanza Venatoria, Genoa, Italy
| | - Christian Chioso
- Regione Autonoma Valle d'Aosta - Flora e fauna - Ufficio per la fauna selvatica e ittica, Quart, Italy
| | - Fabrizio Truc
- Regione Autonoma Valle d'Aosta - Flora e fauna - Ufficio per la fauna selvatica e ittica, Quart, Italy
| | - Giulia Bombieri
- MUSE - Museo delle Scienze di Trento, Conservation Biology Section, Trento, Italy
| | - Luca Pedrotti
- ERSAF - Direzione Parco Nazionale dello Stelvio, Sondrio, Italy
| | - Davide Righetti
- Provincia Autonoma di Bolzano, Ripartizione Foreste, Ufficio Caccia e Pesca, Bolzano, Italy
| | - Pierluigi L Acutis
- Istituto Zooprofilattico Sperimentale del Piemonte. Liguria e Valle d'Aosta, Genetics Laboratory, Turin, Italy
| | - Fabio Guglielmo
- Regione Autonoma Valle d'Aosta, Biodiversità, sostenibilità e aree naturali protette, Museo regionale di Scienze naturali Efisio Noussan, Saint-Christophe, Italy
| | - Heidi C Hauffe
- Conservation Genomics Research Unit, Research and Innovation Centre, Fondazione E. Mach, San Michele all'Adige, Italy
| | - Chiara Rossi
- Conservation Genomics Research Unit, Research and Innovation Centre, Fondazione E. Mach, San Michele all'Adige, Italy
| | - Romolo Caniglia
- ISPRA Institute for Environmental Protection and Research, Wildlife Coordination Service, Rome, Italy
| | - Paola Aragno
- ISPRA Institute for Environmental Protection and Research, Wildlife Coordination Service, Rome, Italy
| | - Valentina La Morgia
- ISPRA Institute for Environmental Protection and Research, Wildlife Coordination Service, Rome, Italy
| | - Piero Genovesi
- ISPRA Institute for Environmental Protection and Research, Wildlife Coordination Service, Rome, Italy
| | - Richard Bischof
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
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2
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Marucco F, Reinhardt I, Avanzinelli E, Zimmermann F, Manz R, Potočnik H, Černe R, Rauer G, Walter T, Knauer F, Chapron G, Duchamp C. Transboundary Monitoring of the Wolf Alpine Population over 21 Years and Seven Countries. Animals (Basel) 2023; 13:3551. [PMID: 38003168 PMCID: PMC10668717 DOI: 10.3390/ani13223551] [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: 09/17/2023] [Revised: 10/31/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Wolves have large spatial requirements and their expansion in Europe is occurring over national boundaries, hence the need to develop monitoring programs at the population level. Wolves in the Alps are defined as a functional population and management unit. The range of this wolf Alpine population now covers seven countries: Italy, France, Austria, Switzerland, Slovenia, Liechtenstein and Germany, making the development of a joint and coordinated monitoring program particularly challenging. In the framework of the Wolf Alpine Group (WAG), researchers developed uniform criteria for the assessment and interpretation of field data collected in the frame of different national monitoring programs. This standardization allowed for data comparability across borders and the joint evaluation of distribution and consistency at the population level. We documented the increase in the number of wolf reproductive units (packs and pairs) over 21 years, from 1 in 1993-1994 up to 243 units in 2020-2021, and examined the pattern of expansion over the Alps. This long-term and large-scale approach is a successful example of transboundary monitoring of a large carnivore population that, despite administrative fragmentation, provides robust indexes of population size and distribution that are of relevance for wolf conservation and management at the transnational Alpine scale.
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Affiliation(s)
- Francesca Marucco
- Department of Life Sciences and Systems Biology, University of Turin, Via Accademia Albertina 13, 10123 Turin, Italy
| | - Ilka Reinhardt
- LUPUS-German Institute for Wolf Monitoring and Research, Dorfaue 9, 02979 Spreewitz, Germany
- Department of Biological Sciences, Goethe-University Frankfurt am Main, 60438 Frankfurt, Germany
| | - Elisa Avanzinelli
- Centro Grandi Carnivori, Ente di Gestione Aree Protette Alpi Marittime, Piazza Regina Elena 30, Valdieri, 12010 Cuneo, Italy
| | - Fridolin Zimmermann
- KORA-Carnivore Ecology and Wildlife Management, Talgut Zentrum 5, CH-3063 Ittigen, Switzerland
- Department of Ecology and Evolution, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Ralph Manz
- KORA-Carnivore Ecology and Wildlife Management, Talgut Zentrum 5, CH-3063 Ittigen, Switzerland
| | - Hubert Potočnik
- Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
| | - Rok Černe
- Slovenia Forest Service, Večna Pot 2, 1000 Ljubljana, Slovenia
| | - Georg Rauer
- Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstr. 1, A-1160 Vienna, Austria
| | - Theresa Walter
- Conservation Medicine Unit, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstr. 1, A-1160 Vienna, Austria
| | - Felix Knauer
- Conservation Medicine Unit, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstr. 1, A-1160 Vienna, Austria
| | - Guillaume Chapron
- Department of Ecology, Swedish University of Agricultural Sciences, 739-93 Riddarhyttan, Sweden
| | - Christophe Duchamp
- Office Français de la Biodiversité, Department of Research and Expertise, Parc Micropolis, F-05000 Gap, France
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3
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Balmori‐de la Puente A, Escoda L, Fernández‐González Á, Menéndez‐Pérez D, González‐Esteban J, Castresana J. Evaluating the use of non-invasive hair sampling and ddRAD to characterize populations of endangered species: Application to a peripheral population of the European mink. Ecol Evol 2023; 13:e10530. [PMID: 37727778 PMCID: PMC10506391 DOI: 10.1002/ece3.10530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 07/17/2023] [Accepted: 08/30/2023] [Indexed: 09/21/2023] Open
Abstract
The application of next-generation sequencing (NGS) to non-invasive samples is one of the most promising methods in conservation genomics, but these types of samples present significant challenges for NGS. The European mink (Mustela lutreola) is critically endangered throughout its range. However, important aspects such as census size and inbreeding remain still unknown in many populations, so it is crucial to develop new methods to monitor this species. In this work, we placed hair tubes along riverbanks in a border area of the Iberian population, which allowed the genetic identification of 76 European mink hair samples. We then applied a reduced representation genomic sequencing (ddRAD) technique to a subset of these samples to test whether we could extract sufficient genomic information from them. We show that several problems with the DNA, including contamination, fragmentation, oxidation, and possibly sample mixing, affected the samples. Using various bioinformatic techniques to reduce these problems, we were able to unambiguously genotype 19 hair samples belonging to six individuals. This small number of individuals showed that the demographic status of the species in this peripheral population is worse than expected. The data obtained also allowed us to perform preliminary analyses of relatedness and inbreeding. Although further improvements in sampling and analysis are needed, the application of the ddRAD technique to non-invasively obtained hairs represents a significant advance in the genomic study of endangered species.
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Affiliation(s)
| | - Lídia Escoda
- Institute of Evolutionary Biology (CSIC‐Universitat Pompeu Fabra)BarcelonaSpain
| | | | | | | | - Jose Castresana
- Institute of Evolutionary Biology (CSIC‐Universitat Pompeu Fabra)BarcelonaSpain
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4
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Brooks GC, Wendt A, Haas CA, Roberts JH. Comparing estimates of census and effective population size in an endangered amphibian. Anim Conserv 2023. [DOI: 10.1111/acv.12871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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5
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Zhang W, Chipperfield JD, Illian JB, Dupont P, Milleret C, de Valpine P, Bischof R. A flexible and efficient Bayesian implementation of point process models for spatial capture-recapture data. Ecology 2023; 104:e3887. [PMID: 36217822 PMCID: PMC10078592 DOI: 10.1002/ecy.3887] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 07/29/2022] [Accepted: 08/29/2022] [Indexed: 02/01/2023]
Abstract
Spatial capture-recapture (SCR) is now routinely used for estimating abundance and density of wildlife populations. A standard SCR model includes sub-models for the distribution of individual activity centers (ACs) and for individual detections conditional on the locations of these ACs. Both sub-models can be expressed as point processes taking place in continuous space, but there is a lack of accessible and efficient tools to fit such models in a Bayesian paradigm. Here, we describe a set of custom functions and distributions to achieve this. Our work allows for more efficient model fitting with spatial covariates on population density, offers the option to fit SCR models using the semi-complete data likelihood (SCDL) approach instead of data augmentation, and better reflects the spatially continuous detection process in SCR studies that use area searches. In addition, the SCDL approach is more efficient than data augmentation for simple SCR models while losing its advantages for more complicated models that account for spatial variation in either population density or detection. We present the model formulation, test it with simulations, quantify computational efficiency gains, and conclude with a real-life example using non-invasive genetic sampling data for an elusive large carnivore, the wolverine (Gulo gulo) in Norway.
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Affiliation(s)
- Wei Zhang
- Department of Environmental Science, Policy and Management, University of California Berkeley, Berkeley, California, USA.,School of Mathematics and Statistics, University of Glasgow, Glasgow, UK
| | - Joseph D Chipperfield
- Faculty of Life Sciences and Natural Resource Management, Norwegian University of Life Sciences, Trondheim, Norway.,Norwegian Institute for Nature Research, Høyteknologisenteret, Bergen, Norway
| | - Janine B Illian
- School of Mathematics and Statistics, University of Glasgow, Glasgow, UK
| | - Pierre Dupont
- Faculty of Life Sciences and Natural Resource Management, Norwegian University of Life Sciences, Trondheim, Norway
| | - Cyril Milleret
- Faculty of Life Sciences and Natural Resource Management, Norwegian University of Life Sciences, Trondheim, Norway
| | - Perry de Valpine
- Department of Environmental Science, Policy and Management, University of California Berkeley, Berkeley, California, USA
| | - Richard Bischof
- Faculty of Life Sciences and Natural Resource Management, Norwegian University of Life Sciences, Trondheim, Norway
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6
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Braczkowski A, Gopalaswamy AM, Fattebert J, Isoke S, Bezzina A, Maron M. Spatially explicit population estimates of African leopards and spotted hyenas in the Queen Elizabeth Conservation Area of southwestern Uganda. Mamm Biol 2022. [DOI: 10.1007/s42991-022-00324-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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7
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Russo BM, Jones AS, Clement MJ, Fyffe N, Mesler JI, Rubin ES. Camera trapping as a method for estimating abundance of Mexican wolves. WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Brianna M. Russo
- Arizona Game and Fish Department, Research Branch 5000 W. Carefree Highway Phoenix AZ 85086 USA
| | - Andrew S. Jones
- Arizona Game and Fish Department, Research Branch 5000 W. Carefree Highway Phoenix AZ 85086 USA
| | - Matthew J. Clement
- Arizona Game and Fish Department, Research Branch 5000 W. Carefree Highway Phoenix AZ 85086 USA
| | - Nathan Fyffe
- Arizona Game and Fish Department, Research Branch 5000 W. Carefree Highway Phoenix AZ 85086 USA
| | - Jacob I. Mesler
- Arizona Game and Fish Department, Research Branch 5000 W. Carefree Highway Phoenix AZ 85086 USA
| | - Esther S. Rubin
- Arizona Game and Fish Department, Research Branch 5000 W. Carefree Highway Phoenix AZ 85086 USA
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8
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Lombardi JV, Sergeyev M, Tewes ME, Schofield LR, Wilkins RN. Spatial capture-recapture and LiDAR-derived vegetation metrics reveal high densities of ocelots on Texas ranchlands. FRONTIERS IN CONSERVATION SCIENCE 2022. [DOI: 10.3389/fcosc.2022.1003044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Reliable estimates of population density and size are crucial to wildlife conservation, particularly in the context of the Endangered Species Act. In the United States, ocelots (Leopardus pardalis pardalis) were listed as endangered in 1982, and to date, only one population density estimate has been reported in Texas. In this study, we integrated vegetation metrics derived from LiDAR and spatial capture-recapture models to discern factors of ocelot encounter rates and estimated localized population estimates on private ranchlands in coastal southern Texas. From September 2020 to May 2021, we conducted a camera trap study across 42 camera stations on the East Foundation’s El Sauz Ranch, which was positioned within a larger region of highly suitable woody and herbaceous cover for ocelots. We observed a high density of ocelots (17.6 ocelots/100 km2) and a population size of 36.3 ocelots (95% CI: 26.1–58.6) with the 206.25 km2 state space area of habitat. The encounter probability of ocelots increased with greater canopy cover at 1-2 m height and decreasing proximity to woody cover. These results suggest that the incorporation of LiDAR-derived vegetative canopy metrics allowed us to understand where ocelots are likely to be detected, which may aid in current and future population monitoring efforts. These population estimates reflect the first spatially explicit and most recent estimates in a portion of the northernmost population of ocelots in southern Texas. This study further demonstrates the importance of private working lands for the recovery of ocelots in Texas.
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9
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Mäntyniemi S, Helle I, Kojola I. Assessment of the residential Finnish wolf population combines DNA captures, citizen observations and mortality data using a Bayesian state-space model. EUR J WILDLIFE RES 2022. [DOI: 10.1007/s10344-022-01615-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AbstractAssessment of the Finnish wolf population relies on multiple sources of information. This paper describes how Bayesian inference is used to pool the information contained in different data sets (point observations, non-invasive genetics, known mortalities) for the estimation of the number of territories occupied by family packs and pairs. The output of the assessment model is a joint probability distribution, which describes current knowledge about the number of wolves within each territory. The joint distribution can be used to derive probability distributions for the total number of wolves in all territories and for the pack status within each territory. Most of the data set comprises of both voluntary-provided point observations and DNA samples provided by volunteers and research personnel. The new method reduces the role of expert judgement in the assessment process, providing increased transparency and repeatability.
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10
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McMurry S, Moeller AK, Goerz J, Robinson HS. Using space to event modeling to estimate density of multiple species in northeastern Washington. WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Sierra McMurry
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation University of Montana 32 Campus Drive Missoula MT 59812 USA
| | - Anna K. Moeller
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation University of Montana 32 Campus Drive Missoula MT 59812 USA
| | - James Goerz
- Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, W.A. Franke College of Forestry and Conservation University of Montana 32 Campus Drive Missoula MT 59812 USA
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11
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Gardner B, McClintock BT, Converse SJ, Hostetter NJ. Integrated animal movement and spatial capture-recapture models: Simulation, implementation, and inference. Ecology 2022; 103:e3771. [PMID: 35638187 PMCID: PMC9787507 DOI: 10.1002/ecy.3771] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 03/18/2022] [Accepted: 04/19/2022] [Indexed: 12/30/2022]
Abstract
Over the last decade, spatial capture-recapture (SCR) models have become widespread for estimating demographic parameters in ecological studies. However, the underlying assumptions about animal movement and space use are often not realistic. This is a missed opportunity because interesting ecological questions related to animal space use, habitat selection, and behavior cannot be addressed with most SCR models, despite the fact that the data collected in SCR studies - individual animals observed at specific locations and times - can provide a rich source of information about these processes and how they relate to demographic rates. We developed SCR models that integrated more complex movement processes that are typically inferred from telemetry data, including a simple random walk, correlated random walk (i.e., short-term directional persistence), and habitat-driven Langevin diffusion. We demonstrated how to formulate, simulate from, and fit these models with standard SCR data using data-augmented Bayesian analysis methods. We evaluated their performance through a simulation study, in which we varied the detection, movement, and resource selection parameters. We also examined different numbers of sampling occasions and assessed performance gains when including auxiliary location data collected from telemetered individuals. Across all scenarios, the integrated SCR movement models performed well in terms of abundance, detection, and movement parameter estimation. We found little difference in bias for the simple random walk model when reducing the number of sampling occasions from T = 25 to T = 15. We found some bias in movement parameter estimates under several of the correlated random walk scenarios, but incorporating auxiliary location data improved parameter estimates and significantly improved mixing during model fitting. The Langevin movement model was able to recover resource selection parameters from standard SCR data, which is particularly appealing because it explicitly links the individual-level movement process with habitat selection and population density. We focused on closed population models, but the movement models developed here can be extended to open SCR models. The movement process models could also be easily extended to accommodate additional "building blocks" of random walks, such as central tendency (e.g., territoriality) or multiple movement behavior states, thereby providing a flexible and coherent framework for linking animal movement behavior to population dynamics, density, and distribution.
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Affiliation(s)
- Beth Gardner
- School of Environmental and Forest SciencesUniversity of WashingtonSeattleWashingtonUSA
| | - Brett T. McClintock
- Marine Mammal LaboratoryNOAA‐NMFS Alaska Fisheries Science CenterSeattleWashingtonUSA
| | - Sarah J. Converse
- U.S. Geological Survey, Washington Cooperative Fish and Wildlife Research Unit, School of Environmental and Forest Sciences and School of Aquatic and Fishery SciencesUniversity of WashingtonSeattleWashingtonUSA
| | - Nathan J. Hostetter
- U.S. Geological Survey, North Carolina Cooperative Fish and Wildlife Research Unit, Department of Applied EcologyNorth Carolina State UniversityRaleighNorth CarolinaUSA
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12
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Emmet RL, Augustine BC, Abrahms B, Rich LN, Gardner B. A spatial capture-recapture model for group-living species. Ecology 2022; 103:e3576. [PMID: 34714927 DOI: 10.1002/ecy.3576] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 07/09/2021] [Accepted: 08/24/2021] [Indexed: 12/13/2022]
Abstract
Group living in species can have complex consequences for individuals, populations, and ecosystems. Therefore, estimating group density and size is often essential for understanding population dynamics, interspecific interactions, and conservation needs of group-living species. Spatial capture-recapture (SCR) has been used to model both individual and group density in group-living species, but modeling either individual-level or group-level detection results in different biases due to common characteristics of group-living species, such as highly cohesive movement or variation in group size. Furthermore, no SCR method currently estimates group density, individual density, and group size jointly. Using clustered point processes, we developed a cluster SCR model to estimate group density, individual density, and group size. We compared the model to standard SCR models using both a simulation study and a data set of detections of African wild dogs (Lycaon pictus), a group-living carnivore, on camera traps in northern Botswana. We then tested the model's performance under various scenarios of group movement in a separate simulation study. We found that the cluster SCR model outperformed a standard group-level SCR model when fitted to data generated with varying group sizes, and mostly recovered previous estimates of wild dog group density, individual density, and group size. We also found that the cluster SCR model performs better as individuals' movements become more correlated with their groups' movements. The cluster SCR model offers opportunities to investigate ecological hypotheses relating group size to population dynamics while accounting for cohesive movement behaviors in group-living species.
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Affiliation(s)
- Robert L Emmet
- Quantitative Ecology and Resource Management, University of Washington, Seattle, Washington, USA
| | - Ben C Augustine
- Department of Natural Resources and the Environment, Cornell University, Ithaca, New York, USA
| | - Briana Abrahms
- Department of Biology, Center for Ecosystem Sentinels, University of Washington, Seattle, Washington, USA
| | - Lindsey N Rich
- California Department of Fish and Wildlife, Wildlife Diversity Program, West Sacramento, California, USA
| | - Beth Gardner
- School of Environmental and Forest Sciences, University of Washington, Seattle, Washington, USA
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13
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Batter TJ, Bush JP, Sacks BN. Robustness of fecal DNA spatial capture‐recapture to clustered space‐use by tule elk. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Thomas J. Batter
- Mammalian Ecology and Conservation Unit, Veterinary Genetics Laboratory, School of Veterinary Medicine, 1 Shields Avenue University of California, Davis Davis CA 95616 USA
| | - Joshua P. Bush
- California Department of Fish and Wildlife 1701 Nimbus Rd, North‐Central Region Rancho Cordova CA 95670 USA
| | - Benjamin N. Sacks
- Mammalian Ecology and Conservation Unit, Veterinary Genetics Laboratory, and Department of Population Health and Reproduction, School of Veterinary Medicine, 1 Shields Avenue University of California, Davis Davis CA 95616 USA
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14
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Henk M, Hilson C, Bean WT, Barton DC, Gunther MS. Noninvasive genetic sampling with a spatial capture‐recapture analysis to estimate abundance of Roosevelt elk. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Makenzie Henk
- Department of Wildlife California State Polytechnic University, Humboldt, 1 Harpst Street Arcata CA 95521 USA
| | - Carrington Hilson
- California Department of Fish and Wildlife, 619 2nd Street Eureka CA 95501 USA
| | - William T. Bean
- Department of Wildlife California State Polytechnic University, Humboldt, 1 Harpst Street Arcata CA 95521 USA
| | - Daniel C. Barton
- Department of Wildlife California State Polytechnic University, Humboldt, 1 Harpst Street Arcata CA 95521 USA
| | - Micaela Szykman Gunther
- Department of Wildlife California State Polytechnic University, Humboldt, 1 Harpst Street Arcata CA 95521 USA
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15
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Hanslowe EB, Yackel Adams AA, Nafus MG, Page DA, Bradke DR, Erickson FT, Bailey LL. Chew-cards can accurately index invasive rat densities in Mariana Island forests. NEOBIOTA 2022. [DOI: 10.3897/neobiota.74.80242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Rats (Rattus spp.) are likely established on 80–90% of the world’s islands and represent one of the most damaging and expensive biological invaders. Effective rat control tools exist but require accurate population density estimates or indices to inform treatment timing and effort and to assess treatment efficacy. Capture-mark-recapture data are frequently used to produce robust density estimates, but collecting these data can be expensive, time-consuming, and labor-intensive. We tested a potentially cheaper and easier alternative, chew-cards, as a count-based (quantitative) index of invasive rat densities in tropical forests in the Mariana Islands, an archipelago in the western North Pacific Ocean. We trialed chew-cards in nine forest grids on two Mariana Islands by comparing the proportion of cards chewed to capture-mark-recapture density estimates and manipulated rat densities to test whether the relationship was retained. Chew-card counts were positively correlated with rat capture-mark-recapture density estimates across a range of rat densities found in the region. Additionally, the correlation between the two sampling methods increased with the number of days chew-cards were deployed. Specifically, when chew-cards were deployed for five nights, a 10% increase in the proportion of cards chewed equated to an estimated increase in rat density of approximately 2.4 individuals per ha (R2 = 0.74). Chew-cards can provide a valid index of rat densities in Mariana Island forests and are a cheaper alternative to capture-mark-recapture sampling when relative differences in density are of primary interest. New cost-effective monitoring tools can enhance our understanding and management of invaded islands while stretching limited resources further than some conventional approaches, thus improving invasive species management on islands.
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16
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Davis RS, Gentle LK, Stone EL, Uzal A, Yarnell RW. A review of spotted hyaena population estimates highlights the need for greater utilisation of spatial capture-recapture methods. JOURNAL OF VERTEBRATE BIOLOGY 2022. [DOI: 10.25225/jvb.22017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Robert S. Davis
- School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Nottinghamshire, United Kingdom; e-mail: , , ,
| | - Louise K. Gentle
- School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Nottinghamshire, United Kingdom; e-mail: , , ,
| | - Emma L. Stone
- Department of Applied Sciences, University of the West of England, UK & Conservation Research Africa, Lilongwe, Malawi; e-mail:
| | - Antonio Uzal
- School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Nottinghamshire, United Kingdom; e-mail: , , ,
| | - Richard W. Yarnell
- School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Nottinghamshire, United Kingdom; e-mail: , , ,
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17
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Reynolds‐Hogland MJ, Ramsey AB, Muench C, Pilgrim KL, Engkjer C, Ramsey PW. Age-specific, population-level pedigree of wild black bears provides insights into reproduction, paternity, and maternal effects on offspring apparent survival. Ecol Evol 2022; 12:e8770. [PMID: 35386864 PMCID: PMC8969918 DOI: 10.1002/ece3.8770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 03/04/2022] [Accepted: 03/10/2022] [Indexed: 11/09/2022] Open
Abstract
Wildlife pedigrees provide insights into ecological and evolutionary processes. DNA obtained from noninvasively collected hair is often used to determine individual identities for pedigrees and other genetic analyses. However, detection rates associated with some noninvasive DNA studies can be relatively low, and genetic data do not provide information on individual birth year. Supplementing hair DNA stations with video cameras should increase the individual detection rate, assuming accurate identification of individuals via video data. Video data can also provide birth year information for individuals captured as young of the year, which can enrich population-level pedigrees. We placed video cameras at hair stations and combined genetic and video data to reconstruct an age-specific, population-level pedigree of wild black bears during 2010-2020. Combining individual birth year with mother-offspring relatedness, we also estimated litter size, interlitter interval, primiparity, and fecundity. We used the Cormack-Jolly-Seber model in Program Mark to evaluate the effect of maternal identity on offspring apparent survival. We compared model rankings of apparent survival and parameter estimates based on combined genetic and video data with those based on only genetic data. We observed 42 mother-offspring relationships. Of these, 21 (50%) would not have been detected had we used hair DNA alone. Moreover, video data allowed for the cub and yearling age classes to be determined. Mean annual fecundity was 0.42 (95% CI: 0.27, 0.56). Maternal identity influenced offspring apparent survival, where offspring of one mother experienced significantly lower apparent survival (0.39; SE = 0.15) than that of offspring of four other mothers (0.89-1.00; SE = 0.00-0.06). We video-documented cub abandonment by the mother whose offspring experienced low apparent survival, indicating individual behaviors (e.g., maternal care) may scale up to affect population-level parameters (e.g., cub survival). Our findings provide insights into evolutionary processes and are broadly relevant to wildlife ecology and conservation.
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Affiliation(s)
| | | | | | - Kristine L. Pilgrim
- USDA National Genomics CenterRocky Mountain Research StationMissoulaMontanaUSA
| | - Cory Engkjer
- USDA National Genomics CenterRocky Mountain Research StationMissoulaMontanaUSA
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18
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Western G, Elliot NB, Sompeta SL, Broekhuis F, Ngene S, Gopalaswamy AM. Lions in a coexistence landscape: Repurposing a traditional field technique to monitor an elusive carnivore. Ecol Evol 2022; 12:e8662. [PMID: 35261749 PMCID: PMC8888262 DOI: 10.1002/ece3.8662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 01/28/2022] [Accepted: 02/02/2022] [Indexed: 11/23/2022] Open
Abstract
Throughout Africa, lions are thought to have experienced dramatic population decline and range contraction. The greatest declines are likely occurring in human‐dominated landscapes where reliably estimating lion populations is particularly challenging. By adapting a method that has thus far only been applied to animals that are habituated to vehicles, we estimate lion density in two community areas in Kenya's South Rift, located more than 100 km from the nearest protected area (PA). More specifically, we conducted an 89‐day survey using unstructured spatial sampling coupled with playbacks, a commonly used field technique, and estimated lion density using spatial capture‐recapture (SCR) models. Our estimated density of 5.9 lions over the age of 1 year per 100 km2 compares favorably with many PAs and suggests that this is a key lion population that could be crucial for connectivity across the wider landscape. We discuss the possible mechanisms supporting this density and demonstrate how rigorous field methods combined with robust analyses can produce reliable population estimates within human‐dominated landscapes.
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Affiliation(s)
- Guy Western
- South Rift Association of Landowners Nairobi Kenya
| | - Nicholas B. Elliot
- Kenya Wildlife Trust Nairobi Kenya
- Department of Zoology Wildlife Conservation Research UnitRecanati‐Kaplan CentreUniversity of Oxford Oxford UK
| | | | - Femke Broekhuis
- Wildlife Ecology and Conservation Group Wageningen University and Research Wageningen The Netherlands
| | | | - Arjun M. Gopalaswamy
- Carnassials Global Bengaluru India
- Wildlife Conservation Society Global Conservation Programs Bronx New York USA
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19
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Dey S, Bischof R, Dupont PPA, Milleret C. Does the punishment fit the crime? Consequences and diagnosis of misspecified detection functions in Bayesian spatial capture-recapture modeling. Ecol Evol 2022; 12:e8600. [PMID: 35222967 PMCID: PMC8847120 DOI: 10.1002/ece3.8600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/14/2022] [Accepted: 01/19/2022] [Indexed: 11/11/2022] Open
Abstract
Spatial capture-recapture (SCR) analysis is now used routinely to inform wildlife management and conservation decisions. It is therefore imperative that we understand the implications of and can diagnose common SCR model misspecifications, as flawed inferences could propagate to policy and interventions. The detection function of an SCR model describes how an individual's detections are distributed in space. Despite the detection function's central role in SCR, little is known about the robustness of SCR-derived abundance estimates and home range size estimates to misspecifications. Here, we set out to (a) determine whether abundance estimates are robust to a wider range of misspecifications of the detection function than previously explored, (b) quantify the sensitivity of home range size estimates to the choice of detection function, and (c) evaluate commonly used Bayesian p-values for detecting misspecifications thereof. We simulated SCR data using different circular detection functions to emulate a wide range of space use patterns. We then fit Bayesian SCR models with three detection functions (half-normal, exponential, and half-normal plateau) to each simulated data set. While abundance estimates were very robust, estimates of home range size were sensitive to misspecifications of the detection function. When misspecified, SCR models with the half-normal plateau and exponential detection functions produced the most and least reliable home range size, respectively. Misspecifications with the strongest impact on parameter estimates were easily detected by Bayesian p-values. Practitioners using SCR exclusively for density estimation are unlikely to be impacted by misspecifications of the detection function. However, the choice of detection function can have substantial consequences for the reliability of inferences about space use. Although Bayesian p-values can aid the diagnosis of detection function misspecification under certain conditions, we urge the development of additional custom goodness-of-fit diagnostics for Bayesian SCR models to identify a wider range of model misspecifications.
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Affiliation(s)
- Soumen Dey
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life SciencesÅsNorway
| | - Richard Bischof
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life SciencesÅsNorway
| | - Pierre P. A. Dupont
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life SciencesÅsNorway
| | - Cyril Milleret
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life SciencesÅsNorway
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20
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Braczkowski A, Schenk R, Samarasinghe D, Biggs D, Richardson A, Swanson N, Swanson M, Dheer A, Fattebert J. Leopard and spotted hyena densities in the Lake Mburo National Park, southwestern Uganda. PeerJ 2022; 10:e12307. [PMID: 35127275 PMCID: PMC8801179 DOI: 10.7717/peerj.12307] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 09/22/2021] [Indexed: 01/06/2023] Open
Abstract
Robust measures of animal densities are necessary for effective wildlife management. Leopards (Panthera pardus) and spotted hyenas (Crocuta Crocuta) are higher order predators that are data deficient across much of their East African range and in Uganda, excepting for one peer-reviewed study on hyenas, there are presently no credible population estimates for these species. A lack of information on the population status and even baseline densities of these species has ramifications as leopards are drawcards for the photo-tourism industry, and along with hyenas are often responsible for livestock depredations from pastoralist communities. Leopards are also sometimes hunted for sport. Establishing baseline density estimates for these species is urgently needed not only for population monitoring purposes, but in the design of sustainable management offtakes, and in assessing certain conservation interventions like financial compensation for livestock depredation. Accordingly, we ran a single-season survey of these carnivores in the Lake Mburo National Park of south-western Uganda using 60 remote camera traps distributed in a paired format at 30 locations. We analysed hyena and leopard detections under a Bayesian spatially explicit capture-recapture (SECR) modelling framework to estimate their densities. This small national park (370 km2) is surrounded by Bahima pastoralist communities with high densities of cattle on the park edge (with regular park incursions). Leopard densities were estimated at 6.31 individuals/100 km2 (posterior SD = 1.47, 95% CI [3.75-9.20]), and spotted hyena densities were 10.99 individuals/100 km2, but with wide confidence intervals (posterior SD = 3.35, 95% CI [5.63-17.37]). Leopard and spotted hyena abundance within the boundaries of the national park were 24.87 (posterior SD 7.78) and 39.07 individuals (posterior = SD 13.51) respectively. Leopard densities were on the middle end of SECR studies published in the peer-reviewed literature over the last 5 years while spotted hyena densities were some of the first reported in the literature using SECR, and similar to a study in Botswana which reported 11.80 spotted hyenas/100 km2. Densities were not noticeably lower at the park edge, and in the southwest of our study site, despite repeated cattle incursions into these areas. We postulate that the relatively high densities of both species in the region could be owed to impala Aepyceros melampus densities ranging from 16.6-25.6 impala/km2. Another, potential explanatory variable (albeit a speculative one) is the absence of interspecific competition from African lions (Panthera leo), which became functionally extinct (there is only one male lion present) in the park nearly two decades ago. This study provides the first robust population estimate of these species anywhere in Uganda and suggests leopards and spotted hyenas continue to persist in the highly modified landscape of Lake Mburo National Park.
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Affiliation(s)
- Aleksander Braczkowski
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China,Resilient Conservation Group, Centre for Planetary Health and Food Security, Griffith University, Nathan, Queensland, Australia,School of Natural Resource Management, Nelson Mandela University, George Campus, George, Western Cape, South Africa
| | | | - Dinal Samarasinghe
- Wildlife Research and Nature Conservation Foundation (WRNCF), Colombo, Sri Lanka
| | - Duan Biggs
- Resilient Conservation Group, Centre for Planetary Health and Food Security, Griffith University, Nathan, Queensland, Australia,School of Earth and Sustainability. Northern Arizona University, Flagstaff, Az, USA,Centre for Complex Systems in Transition, School of Public Leadership, Stellenbosch University, Stellenbosch, South Africa
| | - Allie Richardson
- School of Biological Science, The University of Queensland, Brisbane, Queensland
| | | | | | - Arjun Dheer
- Department of Evolutionary Ecology, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Julien Fattebert
- Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, United States,Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Durban, KwaZulu-Natal, South Africa
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21
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Masías VH, Crespo R FA, Navarro R P, Masood R, Krämer NC, Hoppe HU. On spatial variation in the detectability and density of social media user protest supporters. TELEMATICS AND INFORMATICS 2021. [DOI: 10.1016/j.tele.2021.101730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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22
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Mena JL, Yagui H, Tejeda V, Bonifaz E, Bellemain E, Valentini A, Tobler MW, Sánchez-Vendizú P, Lyet A. Environmental DNA metabarcoding as a useful tool for evaluating terrestrial mammal diversity in tropical forests. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02335. [PMID: 33780592 DOI: 10.1002/eap.2335] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 11/04/2020] [Accepted: 01/14/2021] [Indexed: 06/12/2023]
Abstract
Innovative techniques, such as environmental DNA (eDNA) metabarcoding, are now promoting broader biodiversity monitoring at unprecedented scales, because of the reduction in time, presumably lower cost, and methodological efficiency. Our goal was to assess the efficiency of established inventory techniques (live-trapping grids, pitfall traps, camera trapping, mist netting) as well as eDNA for detecting Amazonian mammals. For terrestrial small mammals, we used 32 live-trapping grids based on Sherman and Tomahawk traps (total effort of 10,368 trap-nights); in addition to 16 pitfall traps (1,408 trap-nights). For bats, we used mist nets at 8 sites (4,800 net hours). For medium and large mammals, we used 72 camera trap stations (5,208 camera-days). We identified vertebrate and mammal taxa based on eDNA analysis (12S region, with V05 and Mamm01 markers) from water samples, including a total of 11 3-km transects for stagnant water sampling and seven small streams for running water sampling. A total of 106 mammal species were recorded. Building on sample-based rarefaction and extrapolation curves, both trapping grids and pitfall were successful, recording 91.16% and 82.1% of the expected species for these techniques (~22 and ~9 species), and 16.98% and 6.60% of the total recorded mammal species, respectively. Mist nets recorded 83.2% of the expected bat species (~48), and 34.91% of the total recorded species. Camera trapping recorded 99.2% of the predicted large- and medium-sized species (~31), and 33.02% of the total recorded species. eDNA recorded 75.4% of the expected mammal species for this technique (~68), and 47.0% of the total recorded species. eDNA resulted in a useful tool that saves on effort and reduces sampling costs. This study is among the first to show the large potential of eDNA metabarcoding for assessing Amazonian mammal communities, providing, in combination with conventional techniques, a rapid overview of mammal diversity with broad applications to monitoring, management and conservation. By including appropriate genetic markers and updated reference databases, eDNA metabarcoding method can be extended to the whole vertebrate community.
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Affiliation(s)
- José Luis Mena
- World Wildlife Fund-Perú, Trinidad Moran 853, Lima 14, Peru
| | | | - Vania Tejeda
- World Wildlife Fund-Perú, Trinidad Moran 853, Lima 14, Peru
- Museo de Historia Natural de la Universidad Nacional de San Agustín de Arequipa, Av. Alcides Carrión S/N, Arequipa, Peru
| | - Emilio Bonifaz
- Museo de Historia Natural Vera Alleman Haeghebaert, Universidad Ricardo Palma, Lima 33, Perú
| | - Eva Bellemain
- SPYGEN, 17 rue du Lac St André, Savoie Technolac, BP20274, Le Bourget du Lac, 73375, France
| | - Alice Valentini
- SPYGEN, 17 rue du Lac St André, Savoie Technolac, BP20274, Le Bourget du Lac, 73375, France
| | - Mathias W Tobler
- San Diego Zoo Global, Institute for Conservation Research, 15600 San Pasqual Valley Road, Escondido, California, 92027, USA
| | - Pamela Sánchez-Vendizú
- Facultad de Ciencias Biológicas de la Universidad Nacional Mayor de San Marcos, Ca. German Amezaga 375, Lima, Peru
| | - Arnaud Lyet
- World Wildlife Fund, 1250 24th Street NW, Washington, D.C., 20037, USA
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23
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Crum NJ, Neyman LC, Gowan TA. Abundance estimation for line transect sampling: A comparison of distance sampling and spatial capture-recapture models. PLoS One 2021; 16:e0252231. [PMID: 34048456 PMCID: PMC8162584 DOI: 10.1371/journal.pone.0252231] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/11/2021] [Indexed: 11/18/2022] Open
Abstract
Accurate and precise abundance estimation is vital for informed wildlife conservation and management decision-making. Line transect surveys are a common sampling approach for abundance estimation. Distance sampling is often used to estimate abundance from line transect survey data; however, search encounter spatial capture-recapture can also be used when individuals in the population of interest are identifiable. The search encounter spatial capture-recapture model has rarely been applied, and its performance has not been compared to that of distance sampling. We analyzed simulated datasets to compare the performance of distance sampling and spatial capture-recapture abundance estimators. Additionally, we estimated the abundance of North Atlantic right whales in the southeastern United States with two formulations of each model and compared the estimates. Spatial capture-recapture abundance estimates had lower root mean squared error than distance sampling estimates. Spatial capture-recapture 95% credible intervals for abundance had nominal coverage, i.e., contained the simulating value for abundance in 95% of simulations, whereas distance sampling credible intervals had below nominal coverage. Moreover, North Atlantic right whale abundance estimates from distance sampling models were more sensitive to model specification compared to spatial capture-recapture estimates. When estimating abundance from line transect data, researchers should consider using search encounter spatial capture-recapture when individuals in the population of interest are identifiable, when line transects are surveyed over multiple occasions, when there is imperfect detection of individuals located on the line transect, and when it is safe to assume the population of interest is closed demographically. When line transects are surveyed over multiple occasions, researchers should be aware that individual space use may induce spatial autocorrelation in counts across transects. This is not accounted for in common distance sampling estimators and leads to overly precise abundance estimates.
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Affiliation(s)
- Nathan J. Crum
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, St Petersburg, Florida, United States of America
| | - Lisa C. Neyman
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, St Petersburg, Florida, United States of America
| | - Timothy A. Gowan
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, St Petersburg, Florida, United States of America
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24
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Matias G, Rosalino LM, Rosa JL, Monterroso P. Wildcat population density in
NE
Portugal: A regional stronghold for a nationally threatened felid. POPUL ECOL 2021. [DOI: 10.1002/1438-390x.12088] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Gonçalo Matias
- cE3c‐Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências Universidade de Lisboa Lisbon Portugal
| | - Luís Miguel Rosalino
- cE3c‐Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências Universidade de Lisboa Lisbon Portugal
| | - José Luís Rosa
- Instituto da Conservação da Natureza e Florestas Bragança Portugal
| | - Pedro Monterroso
- CIBIO/InBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos Universidade do Porto Vairão Portugal
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25
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Moeller AK, Nowak JJ, Neufeld L, Bradley M, Manseau M, Wilson P, McFarlane S, Lukacs PM, Hebblewhite M. Integrating counts, telemetry, and non‐invasive DNA data to improve demographic monitoring of an endangered species. Ecosphere 2021. [DOI: 10.1002/ecs2.3443] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Anna K. Moeller
- Wildlife Biology Program Department of Ecosystem and Conservation Sciences W.A. Franke College of Forestry and Conservation University of Montana Missoula Montana USA
| | | | | | - Mark Bradley
- Parks Canada, Jasper National Park Jasper Alberta Canada
| | - Micheline Manseau
- Landscape Science and Technology Division Environment and Climate Change Canada Ottawa Ontario Canada
- Biology Department Trent University Peterborough Ontario Canada
| | - Paul Wilson
- Biology Department Trent University Peterborough Ontario Canada
| | - Samantha McFarlane
- Landscape Science and Technology Division Environment and Climate Change Canada Ottawa Ontario Canada
- Biology Department Trent University Peterborough Ontario Canada
| | - Paul M. Lukacs
- Wildlife Biology Program Department of Ecosystem and Conservation Sciences W.A. Franke College of Forestry and Conservation University of Montana Missoula Montana USA
| | - Mark Hebblewhite
- Wildlife Biology Program Department of Ecosystem and Conservation Sciences W.A. Franke College of Forestry and Conservation University of Montana Missoula Montana USA
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26
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Duľa M, Bojda M, Chabanne DBH, Drengubiak P, Hrdý Ľ, Krojerová-Prokešová J, Kubala J, Labuda J, Marčáková L, Oliveira T, Smolko P, Váňa M, Kutal M. Multi-seasonal systematic camera-trapping reveals fluctuating densities and high turnover rates of Carpathian lynx on the western edge of its native range. Sci Rep 2021; 11:9236. [PMID: 33927232 PMCID: PMC8085240 DOI: 10.1038/s41598-021-88348-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 04/09/2021] [Indexed: 11/09/2022] Open
Abstract
Camera-trapping and capture-recapture models are the most widely used tools for estimating densities of wild felids that have unique coat patterns, such as Eurasian lynx. However, studies dealing with this species are predominantly on a short-term basis and our knowledge of temporal trends and population persistence is still scarce. By using systematic camera-trapping and spatial capture-recapture models, we estimated lynx densities and evaluated density fluctuations, apparent survival, transition rate and individual's turnover during five consecutive seasons at three different sites situated in the Czech-Slovak-Polish borderland at the periphery of the Western Carpathians. Our density estimates vary between 0.26 and 1.85 lynx/100 km2 suitable habitat and represent the lowest and the highest lynx densities reported from the Carpathians. We recorded 1.5-4.1-fold changes in asynchronous fluctuated densities among all study sites and seasons. Furthermore, we detected high individual's turnover (on average 46.3 ± 8.06% in all independent lynx and 37.6 ± 4.22% in adults) as well as low persistence of adults (only 3 out of 29 individuals detected in all seasons). The overall apparent survival rate was 0.63 ± 0.055 and overall transition rate between sites was 0.03 ± 0.019. Transition rate of males was significantly higher than in females, suggesting male-biased dispersal and female philopatry. Fluctuating densities and high turnover rates, in combination with documented lynx mortality, indicate that the population in our region faces several human-induced mortalities, such as poaching or lynx-vehicle collisions. These factors might restrict population growth and limit the dispersion of lynx to other subsequent areas, thus undermining the favourable conservation status of the Carpathian population. Moreover, our study demonstrates that long-term camera-trapping surveys are needed for evaluation of population trends and for reliable estimates of demographic parameters of wild territorial felids, and can be further used for establishing successful management and conservation measures.
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Affiliation(s)
- Martin Duľa
- Department of Forest Ecology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic. .,Friends of the Earth Czech Republic, Olomouc Branch, Dolní náměstí 38, 779 00, Olomouc, Czech Republic.
| | - Michal Bojda
- Department of Forest Ecology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic.,Friends of the Earth Czech Republic, Olomouc Branch, Dolní náměstí 38, 779 00, Olomouc, Czech Republic
| | - Delphine B H Chabanne
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, WA, Australia.,Evolutionary Genetics Group, Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Peter Drengubiak
- Kysuce Protected Landscape Area Administration, State Nature Conservancy of the Slovak Republic, U Tomali č. 1511, 022 01, Čadca, Slovakia
| | - Ľuboslav Hrdý
- Friends of the Earth Czech Republic, Olomouc Branch, Dolní náměstí 38, 779 00, Olomouc, Czech Republic
| | - Jarmila Krojerová-Prokešová
- Institute of Vertebrate Biology of the Czech Academy of Sciences, Květná 8, 603 65, Brno, Czech Republic.,Department of Zoology, Fisheries, Hydrobiology and Apiculture, Faculty of AgriSciences, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic
| | - Jakub Kubala
- Department of Applied Zoology and Wildlife Management, Faculty of Forestry, Technical University in Zvolen, T. G. Masaryka 24, 960 01, Zvolen, Slovakia.,DIANA - Carpathian Wildlife Research, Mládežnícka 47, 974 04, Banská Bystrica, Slovakia
| | - Jiří Labuda
- Department of Forest Ecology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic.,Friends of the Earth Czech Republic, Olomouc Branch, Dolní náměstí 38, 779 00, Olomouc, Czech Republic
| | - Leona Marčáková
- Friends of the Earth Czech Republic, Olomouc Branch, Dolní náměstí 38, 779 00, Olomouc, Czech Republic
| | - Teresa Oliveira
- Department of Forestry and Renewable Forest Resources, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Peter Smolko
- Department of Applied Zoology and Wildlife Management, Faculty of Forestry, Technical University in Zvolen, T. G. Masaryka 24, 960 01, Zvolen, Slovakia.,DIANA - Carpathian Wildlife Research, Mládežnícka 47, 974 04, Banská Bystrica, Slovakia
| | - Martin Váňa
- Friends of the Earth Czech Republic, Olomouc Branch, Dolní náměstí 38, 779 00, Olomouc, Czech Republic
| | - Miroslav Kutal
- Department of Forest Ecology, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 1, 613 00, Brno, Czech Republic.,Friends of the Earth Czech Republic, Olomouc Branch, Dolní náměstí 38, 779 00, Olomouc, Czech Republic
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Sadhukhan S, Root-Gutteridge H, Habib B. Identifying unknown Indian wolves by their distinctive howls: its potential as a non-invasive survey method. Sci Rep 2021; 11:7309. [PMID: 33790346 PMCID: PMC8012383 DOI: 10.1038/s41598-021-86718-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 03/19/2021] [Indexed: 02/01/2023] Open
Abstract
Previous studies have posited the use of acoustics-based surveys to monitor population size and estimate their density. However, decreasing the bias in population estimations, such as by using Capture-Mark-Recapture, requires the identification of individuals using supervised classification methods, especially for sparsely populated species like the wolf which may otherwise be counted repeatedly. The cryptic behaviour of Indian wolf (Canis lupus pallipes) poses serious challenges to survey efforts, and thus, there is no reliable estimate of their population despite a prominent role in the ecosystem. Like other wolves, Indian wolves produce howls that can be detected over distances of more than 6 km, making them ideal candidates for acoustic surveys. Here, we explore the use of a supervised classifier to identify unknown individuals. We trained a supervised Agglomerative Nesting hierarchical clustering (AGNES) model using 49 howls from five Indian wolves and achieved 98% individual identification accuracy. We tested our model's predictive power using 20 novel howls from a further four individuals (test dataset) and resulted in 75% accuracy in classifying howls to individuals. The model can reduce bias in population estimations using Capture-Mark-Recapture and track individual wolves non-invasively by their howls. This has potential for studies of wolves' territory use, pack composition, and reproductive behaviour. Our method can potentially be adapted for other species with individually distinctive vocalisations, representing an advanced tool for individual-level monitoring.
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Affiliation(s)
- Sougata Sadhukhan
- grid.452923.b0000 0004 1767 4167Animal Ecology and Conservation Biology, Wildlife Institute of India, Dehradun, 248001 India
| | - Holly Root-Gutteridge
- grid.36511.300000 0004 0420 4262Animal Behaviour, Cognition and Welfare Group, University of Lincoln, Lincoln, UK ,grid.12082.390000 0004 1936 7590Reby Lab, School of Psychology, University of Sussex, Brighton, UK
| | - Bilal Habib
- grid.452923.b0000 0004 1767 4167Animal Ecology and Conservation Biology, Wildlife Institute of India, Dehradun, 248001 India
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28
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Sun Y, Chen Y, Díaz-Sacco JJ, Shi K. Assessing population structure and body condition to inform conservation strategies for a small isolated Asian elephant (Elephas maximus) population in southwest China. PLoS One 2021; 16:e0248210. [PMID: 33690688 PMCID: PMC7942997 DOI: 10.1371/journal.pone.0248210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 02/22/2021] [Indexed: 11/24/2022] Open
Abstract
The Asian elephant (Elephas maximus) population in Nangunhe National Nature Reserve in China represents a unique evolutionary branch that has been isolated for more than twenty years from neighboring populations in Myanmar. The scarcity of information on population structure, sex ratio, and body condition makes it difficult to develop effective conservation measures for this elephant population. Twelve individuals were identified from 3,860 valid elephant images obtained from February to June 2018 (5,942 sampling effort nights) at 52 camera sites. Three adult females, three adult males, one subadult male, two juvenile females, two juvenile males and one male calf were identified. The ratio of adult females to adult males was 1:1, and the ratio of reproductive ability was 1:0.67, indicating the scarcity of reproductive females as an important limiting factor to population growth. A population density of 5.32 ± 1.56 elephants/100 km2 was estimated using Spatially Explicit Capture Recapture (SECR) models. The health condition of this elephant population was assessed using an 11-point scale of Body Condition Scoring (BCS). The average BCS was 5.75 (n = 12, range 2–9), with adult females scoring lower than adult males. This isolated population is extremely small and has an inverted pyramid age structure and therefore is at a high risk of extinction. We propose three plans to improve the survival of this population: improving the quality and quantity of food resources, removing fencing and establishing corridors between the east and wet parts of Nangunhe reserve.
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Affiliation(s)
- Yakuan Sun
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Ying Chen
- School of Biological Science, The University of Hong Kong, Hong Kong, China
| | - Juan José Díaz-Sacco
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
| | - Kun Shi
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, China
- Eco-Bridge Continental, Beijing, China
- * E-mail:
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29
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McFarlane S, Manseau M, Steenweg R, Hervieux D, Hegel T, Slater S, Wilson PJ. An assessment of sampling designs using SCR analyses to estimate abundance of boreal caribou. Ecol Evol 2020; 10:11631-11642. [PMID: 33144989 PMCID: PMC7593142 DOI: 10.1002/ece3.6797] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 08/06/2020] [Accepted: 08/20/2020] [Indexed: 11/12/2022] Open
Abstract
Accurately estimating abundance is a critical component of monitoring and recovery of rare and elusive species. Spatial capture-recapture (SCR) models are an increasingly popular method for robust estimation of ecological parameters. We provide an analytical framework to assess results from empirical studies to inform SCR sampling design, using both simulated and empirical data from noninvasive genetic sampling of seven boreal caribou populations (Rangifer tarandus caribou), which varied in range size and estimated population density. We use simulated population data with varying levels of clustered distributions to quantify the impact of nonindependence of detections on density estimates, and empirical datasets to explore the influence of varied sampling intensity on the relative bias and precision of density estimates. Simulations revealed that clustered distributions of detections did not significantly impact relative bias or precision of density estimates. The genotyping success rate of our empirical dataset (n = 7,210 samples) was 95.1%, and 1,755 unique individuals were identified. Analysis of the empirical data indicated that reduced sampling intensity had a greater impact on density estimates in smaller ranges. The number of captures and spatial recaptures was strongly correlated with precision, but not absolute relative bias. The best sampling designs did not differ with estimated population density but differed between large and small ranges. We provide an efficient framework implemented in R to estimate the detection parameters required when designing SCR studies. The framework can be used when designing a monitoring program to minimize effort and cost while maximizing effectiveness, which is critical for informing wildlife management and conservation.
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Affiliation(s)
- Samantha McFarlane
- Environmental and Life Sciences DepartmentTrent UniversityPeterboroughOntarioCanada
- Landscape Science and Technology DivisionEnvironment and Climate Change CanadaOttawaONCanada
| | - Micheline Manseau
- Environmental and Life Sciences DepartmentTrent UniversityPeterboroughOntarioCanada
- Landscape Science and Technology DivisionEnvironment and Climate Change CanadaOttawaONCanada
| | - Robin Steenweg
- Fish and Wildlife Stewardship BranchAlberta Environment and ParksGrande PrairieABCanada
- Canadian Wildlife Service—Pacific RegionEnvironment and Climate Change CanadaKelownaBCCanada
| | - Dave Hervieux
- Fish and Wildlife Stewardship BranchAlberta Environment and ParksGrande PrairieABCanada
| | - Troy Hegel
- Regional Resource ManagementAlberta Environment and ParksEdmontonABCanada
| | - Simon Slater
- Fish and Wildlife Stewardship BranchAlberta Environment and ParksEdmontonABCanada
| | - Paul J. Wilson
- Environmental and Life Sciences DepartmentTrent UniversityPeterboroughOntarioCanada
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30
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Milleret C, Dupont P, Chipperfield J, Turek D, Brøseth H, Gimenez O, Valpine P, Bischof R. Estimating abundance with interruptions in data collection using open population spatial capture–recapture models. Ecosphere 2020. [DOI: 10.1002/ecs2.3172] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Cyril Milleret
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås NO‐1432 Norway
| | - Pierre Dupont
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås NO‐1432 Norway
| | - Joseph Chipperfield
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås NO‐1432 Norway
- Norwegian Institute for Nature Research Bergen NO‐5008 Norway
| | - Daniel Turek
- Department of Mathematics & Statistics Williams College Williamstown Massachusetts 01267 USA
| | - Henrik Brøseth
- Norwegian Institute for Nature Research Trondheim NO‐7485 Norway
| | - Olivier Gimenez
- CEFE University of Montpellier CNRS University of Paul Valéry Montpellier 3 EPHE IRD Montpellier France
| | - Perry Valpine
- Department of Environmental Science, Policy & Management University of California Berkeley Berkeley California 94720 USA
| | - Richard Bischof
- Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences Ås NO‐1432 Norway
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Dingo Density Estimates and Movements in Equatorial Australia: Spatially Explicit Mark-Resight Models. Animals (Basel) 2020; 10:ani10050865. [PMID: 32429520 PMCID: PMC7278439 DOI: 10.3390/ani10050865] [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: 03/16/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 11/16/2022] Open
Abstract
Australia is currently free of canine rabies. Spatio-ecological knowledge about dingoes in northern Australia is currently a gap that impedes the application of disease spread models and our understanding of the potential transmission of rabies, in the event of an incursion. We therefore conducted a one-year camera trap survey to monitor a dingo population in equatorial northern Australia. The population is contiguous with remote Indigenous communities containing free-roaming dogs, which potentially interact with dingoes. Based on the camera trap data, we derived dingo density and home range size estimates using maximum-likelihood, spatially explicit, mark-resight models, described dingo movements and evaluated spatial correlation and temporal overlap in activities between dingoes and community dogs. Dingo density estimates varied from 0.135 animals/km2 (95% CI = 0.127-0.144) during the dry season to 0.147 animals/km2 (95% CI = 0.135-0.159) during the wet season. The 95% bivariate Normal home range sizes were highly variable throughout the year (7.95-29.40 km2). Spatial use and daily activity patterns of dingoes and free-roaming community dogs, grouped over ~3 month periods, showed substantial temporal activity overlap and spatial correlation, highlighting the potential risk of disease transmission at the wild-domestic interface in an area of biosecurity risk in equatorial northern Australia. Our results have utility for improving preparedness against a potential rabies incursion.
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32
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Topography and disturbance explain mountain tapir (Tapirus pinchaque) occupancy at its southernmost global range. Mamm Biol 2020. [DOI: 10.1007/s42991-020-00027-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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33
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Donaldson ME, Jackson K, Rico Y, Sayers JB, Ethier DM, Kyle CJ. Development of a massively parallel, genotyping-by-sequencing assay in American badger (Taxidea taxus) highlights the need for careful validation when working with low template DNA. CONSERV GENET RESOUR 2020. [DOI: 10.1007/s12686-020-01146-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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34
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Dröge E, Creel S, Becker MS, Loveridge AJ, Sousa LL, Macdonald DW. Assessing the performance of index calibration survey methods to monitor populations of wide-ranging low-density carnivores. Ecol Evol 2020; 10:3276-3292. [PMID: 32273986 PMCID: PMC7141012 DOI: 10.1002/ece3.6065] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 01/06/2020] [Accepted: 01/08/2020] [Indexed: 11/24/2022] Open
Abstract
Apex carnivores are wide-ranging, low-density, hard to detect, and declining throughout most of their range, making population monitoring both critical and challenging. Rapid and inexpensive index calibration survey (ICS) methods have been developed to monitor large African carnivores. ICS methods assume constant detection probability and a predictable relationship between the index and the actual population of interest. The precision and utility of the resulting estimates from ICS methods have been questioned. We assessed the performance of one ICS method for large carnivores-track counts-with data from two long-term studies of African lion populations. We conducted Monte Carlo simulation of intersections between transects (road segments) and lion movement paths (from GPS collar data) at varying survey intensities. Then, using the track count method we estimated population size and its confidence limits. We found that estimates either overstate precision or are too imprecise to be meaningful. Overstated precision stemmed from discarding the variance from population estimates when developing the method and from treating the conversion from tracks counts to population density as a back-transformation, rather than applying the equation for the variance of a linear function. To effectively assess the status of species, the IUCN has set guidelines, and these should be integrated in survey designs. We propose reporting the half relative confidence interval width (HRCIW) as an easily calculable and interpretable measure of precision. We show that track counts do not adhere to IUCN criteria, and we argue that ICS methods for wide-ranging low-density species are unlikely to meet those criteria. Established, intensive methods lead to precise estimates, but some new approaches, like short, intensive, (spatial) capture-mark-recapture (CMR/SECR) studies, aided by camera trapping and/or genetic identification of individuals, hold promise. A handbook of best practices in monitoring populations of apex carnivores is strongly recommended.
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Affiliation(s)
- Egil Dröge
- Wildlife Conservation Research UnitDepartment of ZoologyThe Recanati‐Kaplan CentreUniversity of OxfordTubneyUK
- Zambian Carnivore ProgrammeMfuweZambia
| | - Scott Creel
- Zambian Carnivore ProgrammeMfuweZambia
- Conservation Biology and Ecology ProgramDepartment of EcologyMontana State UniversityBozemanMontana
- Department of WildlifeFish and Environmental StudiesUmeåSweden
| | - Matthew S. Becker
- Zambian Carnivore ProgrammeMfuweZambia
- Conservation Biology and Ecology ProgramDepartment of EcologyMontana State UniversityBozemanMontana
| | - Andrew J. Loveridge
- Wildlife Conservation Research UnitDepartment of ZoologyThe Recanati‐Kaplan CentreUniversity of OxfordTubneyUK
| | - Lara L. Sousa
- Wildlife Conservation Research UnitDepartment of ZoologyThe Recanati‐Kaplan CentreUniversity of OxfordTubneyUK
| | - David W. Macdonald
- Wildlife Conservation Research UnitDepartment of ZoologyThe Recanati‐Kaplan CentreUniversity of OxfordTubneyUK
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35
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Bischof R, Dupont P, Milleret C, Chipperfield J, Royle JA. Consequences of ignoring group association in spatial capture–recapture analysis. WILDLIFE BIOLOGY 2020. [DOI: 10.2981/wlb.00649] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Richard Bischof
- R. Bischof ✉ , P. Dupont and C. Milleret, Faculty of Environmental Sciences and Natural Resource Management, Norwegian Univ. of Life Sciences, NO-1432 Aas, Norway
| | - Pierre Dupont
- R. Bischof ✉ , P. Dupont and C. Milleret, Faculty of Environmental Sciences and Natural Resource Management, Norwegian Univ. of Life Sciences, NO-1432 Aas, Norway
| | - Cyril Milleret
- R. Bischof ✉ , P. Dupont and C. Milleret, Faculty of Environmental Sciences and Natural Resource Management, Norwegian Univ. of Life Sciences, NO-1432 Aas, Norway
| | - Joseph Chipperfield
- J. Chipperfield, Norwegian Inst. for Nature, Res., Bergen, Norway. – J. A. Royle, USGS Patuxent Wildlife Research Center, Laurel, MD, USA
| | - J. Andrew Royle
- R. Bischof ✉ , P. Dupont and C. Milleret, Faculty of Environmental Sciences and Natural Resource Management, Norwegian Univ. of Life Sciences, NO-1432 Aas, Norway
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36
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Gimenez O, Gatti S, Duchamp C, Germain E, Laurent A, Zimmermann F, Marboutin E. Spatial density estimates of Eurasian lynx ( Lynx lynx) in the French Jura and Vosges Mountains. Ecol Evol 2019; 9:11707-11715. [PMID: 31695880 PMCID: PMC6822030 DOI: 10.1002/ece3.5668] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 08/04/2019] [Accepted: 08/28/2019] [Indexed: 11/07/2022] Open
Abstract
Obtaining estimates of animal population density is a key step in providing sound conservation and management strategies for wildlife. For many large carnivores however, estimating density is difficult because these species are elusive and wide-ranging. Here, we focus on providing the first density estimates of the Eurasian lynx (Lynx lynx) in the French Jura and Vosges mountains. We sampled a total of 413 camera trapping sites (with two cameras per site) between January 2011 and April 2016 in seven study areas across seven counties of the French Jura and Vosges mountains. We obtained 592 lynx detections over 19,035 trap days in the Jura mountains and 0 detection over 6,804 trap days in the Vosges mountains. Based on coat patterns, we identified a total number of 92 unique individuals from photographs, including 16 females, 13 males, and 63 individuals of unknown sex. Using spatial capture-recapture (SCR) models, we estimated abundance in the study areas between 5 (SE = 0.1) and 29 (0.2) lynx and density between 0.24 (SE = 0.02) and 0.91 (SE = 0.03) lynx per 100 km2. We also provide a comparison with nonspatial density estimates and discuss the observed discrepancies. Our study is yet another example of the advantage of combining SCR methods and noninvasive sampling techniques to estimate density for elusive and wide-ranging species, like large carnivores. While the estimated densities in the French Jura mountains are comparable to other lynx populations in Europe, the fact that we detected no lynx in the Vosges mountains is alarming. Connectivity should be encouraged between the French Jura mountains, the Vosges mountains, and the Palatinate Forest in Germany where a reintroduction program is currently ongoing. Our density estimates will help in setting a baseline conservation status for the lynx population in France.
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Affiliation(s)
- Olivier Gimenez
- CEFECNRSEPHEIRDUniv MontpellierUniv Paul Valéry Montpellier 3MontpellierFrance
| | - Sylvain Gatti
- Office National de la Chasse et de la Faune SauvageGièresFrance
| | | | - Estelle Germain
- Centre de Recherche et d'Observation sur les Carnivores (CROC)LucyFrance
| | - Alain Laurent
- Office National de la Chasse et de la Faune SauvageGièresFrance
| | | | - Eric Marboutin
- Office National de la Chasse et de la Faune SauvageGièresFrance
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37
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Goswami VR, Yadava MK, Vasudev D, Prasad PK, Sharma P, Jathanna D. Towards a reliable assessment of Asian elephant population parameters: the application of photographic spatial capture-recapture sampling in a priority floodplain ecosystem. Sci Rep 2019; 9:8578. [PMID: 31189980 PMCID: PMC6561924 DOI: 10.1038/s41598-019-44795-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 05/24/2019] [Indexed: 11/17/2022] Open
Abstract
The hitherto difficult task of reliably estimating populations of wide-ranging megafauna has been enabled by advances in capture–recapture methodology. Here we combine photographic sampling with a Bayesian spatially-explicit capture–recapture (SCR) model to estimate population parameters for the endangered Asian elephant Elephas maximus in the productive floodplain ecosystem of Kaziranga National Park, India. Posterior density estimates of herd-living adult females and sub-adult males and females (herd-adults) was 0.68 elephants/km2 (95% Credible Intervals, CrI = 0.56−0.81) while that of adult males was 0.24 elephants/km2 (95% CrI = 0.18−0.30), with posterior density estimates highlighting spatial heterogeneity in elephant distribution. Estimates of the space-usage parameter suggested that herd-adults (\documentclass[12pt]{minimal}
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\begin{document}$${\hat{\sigma }}_{HA}$$\end{document}σˆHA = 5.91 km, 95% CrI = 5.18–6.81) moved around considerably more than adult males (\documentclass[12pt]{minimal}
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\begin{document}$${\hat{\sigma }}_{AM}$$\end{document}σˆAM = 3.64 km, 95% CrI = 3.09–4.34). Based on elephant movement and age–sex composition, we derived the population that contributed individuals sampled in Kaziranga to be 908 herd-adults, 228 adult males and 610 young (density = 0.46 young/km2, SD = 0.06). Our study demonstrates how SCR is suited to estimating geographically open populations, characterising spatial heterogeneity in fine-scale density, and facilitating reliable monitoring to assess population status and dynamics for science and conservation.
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Affiliation(s)
- Varun R Goswami
- Wildlife Conservation Society - India, Bangalore, 560097, Karnataka, India. .,Centre for Wildlife Studies, Bangalore, 560097, Karnataka, India. .,Conservation Initiatives, Guwahati, 781022, Assam, India.
| | - Mahendra K Yadava
- Department of Environment and Forest, Govt. of Assam, Guwahati, 781037, Assam, India
| | - Divya Vasudev
- Wildlife Conservation Society - India, Bangalore, 560097, Karnataka, India.,Centre for Wildlife Studies, Bangalore, 560097, Karnataka, India.,Conservation Initiatives, Guwahati, 781022, Assam, India
| | - Parvathi K Prasad
- Wildlife Conservation Society - India, Bangalore, 560097, Karnataka, India.,Centre for Wildlife Studies, Bangalore, 560097, Karnataka, India
| | - Pragyan Sharma
- Wildlife Conservation Society - India, Bangalore, 560097, Karnataka, India.,Centre for Wildlife Studies, Bangalore, 560097, Karnataka, India
| | - Devcharan Jathanna
- Wildlife Conservation Society - India, Bangalore, 560097, Karnataka, India.,Centre for Wildlife Studies, Bangalore, 560097, Karnataka, India
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38
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Paterson JT, Proffitt K, Jimenez B, Rotella J, Garrott R. Simulation-based validation of spatial capture-recapture models: A case study using mountain lions. PLoS One 2019; 14:e0215458. [PMID: 31002709 PMCID: PMC6474654 DOI: 10.1371/journal.pone.0215458] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 04/02/2019] [Indexed: 11/19/2022] Open
Abstract
Spatial capture-recapture (SCR) models have improved the ability to estimate densities of rare and elusive animals. However, SCR models have seldom been validated even as model formulations diversify and expand to incorporate new sampling methods and/or additional sources of information on model parameters. Information on the relationship between encounter probabilities, sources of additional information, and the reliability of density estimates, is rare but crucial to assessing reliability of SCR-based estimates. We used a simulation-based approach that incorporated prior empirical work to assess the accuracy and precision of density estimates from SCR models using spatially unstructured sampling. To assess the consequences of sparse data and potential sources of bias, we simulated data under six scenarios corresponding to three different levels of search effort and two levels of correlation between search effort and animal density. We then estimated density for each scenario using four models that included increasing amounts of information from harvested individuals and telemetry to evaluate the impact of additional sources of information. Model results were sensitive to the quantity of available information: density estimates based on low search effort were biased high and imprecise, whereas estimates based on high search effort were unbiased and precise. A correlation between search effort and animal density resulted in a positive bias in density estimates, though the bias decreased with increasingly informative datasets. Adding information from harvested individuals and telemetered individuals improved density estimates based on low and moderate effort but had negligible impact for datasets resulting from high effort. We demonstrated that density estimates from SCR models using spatially unstructured sampling are reliable when sufficient information is provided. Accurate density estimates can result if empirical-based simulations such as those presented here are used to develop study designs with appropriate amounts of effort and information sources.
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Affiliation(s)
- J. Terrill Paterson
- Department of Ecology, Montana State University, Bozeman, Montana, United States of America
- Montana Department of Fish, Wildlife and Parks, Bozeman, Montana, United States of America
- * E-mail:
| | - Kelly Proffitt
- Montana Department of Fish, Wildlife and Parks, Bozeman, Montana, United States of America
| | - Ben Jimenez
- Montana Department of Fish, Wildlife and Parks, Bozeman, Montana, United States of America
| | - Jay Rotella
- Department of Ecology, Montana State University, Bozeman, Montana, United States of America
| | - Robert Garrott
- Department of Ecology, Montana State University, Bozeman, Montana, United States of America
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39
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Roffler GH, Waite JN, Pilgrim KL, Zarn KE, Schwartz MK. Estimating abundance of a cryptic social carnivore using spatially explicit capture–recapture. WILDLIFE SOC B 2019. [DOI: 10.1002/wsb.953] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Gretchen H. Roffler
- Alaska Department of Fish and GameDivision of Wildlife Conservation802 3rd StreetDouglasAK99824USA
| | - Jason N. Waite
- Alaska Department of Fish and GameDivision of Wildlife Conservation802 3rd StreetDouglasAK99824USA
| | - Kristine L. Pilgrim
- National Genomics Center for Wildlife and Fish ConservationRocky Mountain Research StationU.S. Department of Agriculture Forest Service800 E BeckwithMissoulaMT59801USA
| | - Katherine E. Zarn
- National Genomics Center for Wildlife and Fish ConservationRocky Mountain Research StationU.S. Department of Agriculture Forest Service800 E BeckwithMissoulaMT59801USA
| | - Michael K. Schwartz
- National Genomics Center for Wildlife and Fish ConservationRocky Mountain Research StationU.S. Department of Agriculture Forest Service800 E BeckwithMissoulaMT59801USA
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40
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Dupont P, Milleret C, Gimenez O, Bischof R. Population closure and the bias‐precision trade‐off in spatial capture–recapture. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13158] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Pierre Dupont
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life Sciences Ås Norway
| | - Cyril Milleret
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life Sciences Ås Norway
| | - Olivier Gimenez
- CEFECNRSUniversity MontpellierUniversity Paul Valéry Montpellier 3EPHEIRD Montpellier France
| | - Richard Bischof
- Faculty of Environmental Sciences and Natural Resource ManagementNorwegian University of Life Sciences Ås Norway
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Murphy SM, Augustine BC, Adams JR, Waits LP, Cox JJ. Integrating multiple genetic detection methods to estimate population density of social and territorial carnivores. Ecosphere 2018. [DOI: 10.1002/ecs2.2479] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Sean M. Murphy
- Louisiana Department of Wildlife and Fisheries; Large Carnivore Program; Lafayette Louisiana 70506 USA
| | - Ben C. Augustine
- Department of Fish and Wildlife Conservation; Virginia Polytechnic Institute and State University; Blacksburg Virginia 24061 USA
| | - Jennifer R. Adams
- Laboratory for Ecological, Evolutionary and Conservation Genetics; Department of Fish and Wildlife Sciences; University of Idaho; Moscow Idaho 83844 USA
| | - Lisette P. Waits
- Laboratory for Ecological, Evolutionary and Conservation Genetics; Department of Fish and Wildlife Sciences; University of Idaho; Moscow Idaho 83844 USA
| | - John J. Cox
- Department of Forestry and Natural Resources; University of Kentucky; Lexington Kentucky 40546 USA
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Mattioli L, Canu A, Passilongo D, Scandura M, Apollonio M. Estimation of pack density in grey wolf ( Canis lupus) by applying spatially explicit capture-recapture models to camera trap data supported by genetic monitoring. Front Zool 2018; 15:38. [PMID: 30305834 PMCID: PMC6171198 DOI: 10.1186/s12983-018-0281-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 09/07/2018] [Indexed: 11/10/2022] Open
Abstract
Background Density estimation is a key issue in wildlife management but is particularly challenging and labour-intensive for elusive species. Recently developed approaches based on remotely collected data and capture-recapture models, though representing a valid alternative to more traditional methods, have found little application to species with limited morphological variation. We implemented a camera trap capture-recapture study to survey wolf packs in a 560-km2 area of Central Italy. Individual recognition of focal animals (alpha) in the packs was possible by relying on morphological and behavioural traits and was validated by non-invasive genotyping and inter-observer agreement tests. Two types (Bayesian and likelihood-based) of spatially explicit capture-recapture (SCR) models were fitted on wolf pack capture histories, thus obtaining an estimation of pack density in the area. Results In two sessions of camera trapping surveys (2014 and 2015), we detected a maximum of 12 wolf packs. A Bayesian model implementing a half-normal detection function without a trap-specific response provided the most robust result, corresponding to a density of 1.21 ± 0.27 packs/100 km2 in 2015. Average pack size varied from 3.40 (summer 2014, excluding pups and lone-transient wolves) to 4.17 (late winter-spring 2015, excluding lone-transient wolves). Conclusions We applied for the first time a camera-based SCR approach in wolves, providing the first robust estimate of wolf pack density for an area of Italy. We showed that this method is applicable to wolves under the following conditions: i) the existence of sufficient phenotypic/behavioural variation and the recognition of focal individuals (i.e. alpha, verified by non-invasive genotyping); ii) the investigated area is sufficiently large to include a minimum number of packs (ideally 10); iii) a pilot study is carried out to pursue an adequate sampling design and to train operators on individual wolf recognition. We believe that replicating this approach in other areas can allow for an assessment of density variation across the wolf range and would provide a reliable reference parameter for ecological studies.
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Affiliation(s)
- Luca Mattioli
- Settore Attività Faunistico Venatoria, Pesca Dilettantistica, Pesca in mare, Regione Toscana, Via A. Testa 2, I-52100 Arezzo, Italy
| | - Antonio Canu
- 2Department of Veterinary Medicine, University of Sassari, via Vienna 2, I-07100 Sassari, Italy
| | - Daniela Passilongo
- 2Department of Veterinary Medicine, University of Sassari, via Vienna 2, I-07100 Sassari, Italy
| | - Massimo Scandura
- 2Department of Veterinary Medicine, University of Sassari, via Vienna 2, I-07100 Sassari, Italy
| | - Marco Apollonio
- 2Department of Veterinary Medicine, University of Sassari, via Vienna 2, I-07100 Sassari, Italy
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Sabino-Marques H, Ferreira CM, Paupério J, Costa P, Barbosa S, Encarnação C, Alpizar-Jara R, Alves PC, Searle JB, Mira A, Beja P, Pita R. Combining genetic non-invasive sampling with spatially explicit capture-recapture models for density estimation of a patchily distributed small mammal. EUR J WILDLIFE RES 2018. [DOI: 10.1007/s10344-018-1206-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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