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Chataigner B, Pilfold NW, Lenguya L, Besnard AG, Gimenez O. Unusual Suspects: Detection Probability Covaries With Vegetation Productivity and Rainfall for Camera Survey of African Leopards ( Panthera pardus pardus). Ecol Evol 2025; 15:e71346. [PMID: 40370352 PMCID: PMC12077962 DOI: 10.1002/ece3.71346] [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: 10/26/2024] [Revised: 04/06/2025] [Accepted: 04/11/2025] [Indexed: 05/16/2025] Open
Abstract
Maximizing detection probability of elusive species enhances the robustness of population and occupancy estimates, which are essential for supporting impactful conservation strategies. Although the number of camera trap studies on leopards is increasing, few have assessed the drivers influencing leopard detection specifically. We used occupancy modeling embedded in a causal inference framework to provide four biologically robust site use models against which to test the influence of six factors likely influencing leopard detectability at the level of encounter probability, trigger probability, and image quality. In this study, vegetation productivity moderated by rainfall was the top predictor of leopard detectability associated with three of the four site use models. While optimizing detection probability improves estimates of population parameters, the cost-effectiveness of the study designs is also an essential criterion to consider for long-term monitoring of elusive species. Camera trap placement involves minimal cost in the early stages of the grid design. Our results suggest that setting cameras in microhabitats of moderate productivity improved leopard detectability in the wet season. This study can inform the design of camera trap studies occurring in semi-arid bushland ecosystems to improve estimates of leopard population and occupancy.
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Wang Y, Liu M, Xia F, Li S. Human activities reshape the spatial overlap between North Chinese leopard and its wild ungulate prey. Front Zool 2024; 21:24. [PMID: 39327595 PMCID: PMC11426093 DOI: 10.1186/s12983-024-00545-z] [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: 04/23/2024] [Accepted: 09/16/2024] [Indexed: 09/28/2024] Open
Abstract
BACKGROUND Rapidly expanding human activities have profoundly changed the habitat use of both large carnivores and their prey, but whether and how human activities affect the interactions between them has received relatively less attention. In this study, we conducted a systematically designed camera-trapping survey on an endangered large carnivore (North Chinese leopard Panthera pardus japonensis) and its wild ungulate prey (Siberian roe deer Capreolus pygargus and wild boar Sus scrofa) in the Taihang Mountains of central North China. Using conditional two-species occupancy model based on data derived from the extensive sampling effort (15,654 camera-days at 102 camera sites), we examined the relationship of spatial use between leopards and each prey species under the effects of human presence, free-ranging cattle, roads and settlements. RESULTS Humans and cattle had contrasting effects on the relationship of spatial use between leopard and roe deer, with higher and lower spatial segregation between them at human and cattle-frequented sites, respectively. Roads might create a shelter for wild boar from leopard predation, with less spatial segregation between them at sites close to the roads. CONCLUSIONS Our findings demonstrate that human activities are reshaping the spatial overlap between large carnivores and their prey, and have non-equivalent effects among different types of human activity. Such effects may further alter the strength of interspecific interactions between predator and prey, with far-reaching influences on the community and ecosystem that require more research.
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Affiliation(s)
- Yidan Wang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
- Institute of Ecology, Peking University, Beijing, 100871, China
| | - Mingzhang Liu
- National Natural History Museum of China, Beijing, 100050, China
| | - Fan Xia
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China
- Institute of Ecology, Peking University, Beijing, 100871, China
| | - Sheng Li
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing, 100871, China.
- Institute of Ecology, Peking University, Beijing, 100871, China.
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3
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McKee RK, Taillie PJ, Hart KM, Lopez CL, Sanjar A, McCleery RA. Ecological function maintained despite mesomammal declines. Sci Rep 2024; 14:19668. [PMID: 39181911 PMCID: PMC11344858 DOI: 10.1038/s41598-024-66534-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 07/02/2024] [Indexed: 08/27/2024] Open
Abstract
Mid-sized mammals (i.e., mesomammals) fulfill important ecological roles, serving as essential scavengers, predators, pollinators, and seed dispersers in the ecosystems they inhabit. Consequently, declines in mesomammal populations have the potential to alter ecological processes and fundamentally change ecosystems. However, ecosystems characterized by high functional redundancy, where multiple species can fulfil similar ecological roles, may be less impacted by the loss of mesomammals and other vertebrates. The Greater Everglades Ecosystem in southern Florida is a historically biodiverse region that has recently been impacted by multiple anthropogenic threats, most notably the introduction of the Burmese python (Python molurus bivittatus). Since pythons became established, mesomammal populations have become greatly reduced. To assess whether these declines in mesomammals have affected two critical ecosystem functions-scavenging and frugivory-we conducted experiments in areas where mesomammals were present and absent. We did not observe significant differences in scavenging or frugivory efficiency in areas with and without mesomammals, but we did observe significant differences in the communities responsible for scavenging and frugivory. Despite the observed evidence of redundancy, the changes in community composition could potentially lead to indirect consequences on processes like seed dispersal and disease dynamics within this ecosystem, emphasizing the need for further study.
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Affiliation(s)
- Rebecca K McKee
- Department of Biology, Mercer University, 1501 Mercer University Drive, Macon, Georgia, 31207, United States.
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, USA.
| | - Paul J Taillie
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, USA
- Department of Geography, University of North Carolina, Chapel Hill, NC, USA
| | - Kristen M Hart
- U.S. Geological Survey, Wetland and Aquatic Research Center, Davie, FL, USA
| | - Christopher L Lopez
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, USA
| | - Adam Sanjar
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, USA
| | - Robert A McCleery
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, USA
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Otte PJ, Cromsigt JPGM, Smit C, Hofmeester TR. Snow cover-related camouflage mismatch increases detection by predators. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024; 341:327-337. [PMID: 38247310 DOI: 10.1002/jez.2784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/23/2024]
Abstract
Camouflage expressed by animals is an adaptation to local environments that certain animals express to maximize survival and fitness. Animals at higher latitudes change their coat color according to a seasonally changing environment, expressing a white coat in winter and a darker coat in summer. The timing of molting is tightly linked to the appearance and disappearance of snow and is mainly regulated by photoperiod. However, due to climate change, an increasing mismatch is observed between the coat color of these species and their environment. Here, we conducted an experiment in northern Sweden, with white and brown decoys to study how camouflage (mis)-match influenced (1) predator attraction to decoys, and (2) predation events. Using camera trap data, we showed that mismatching decoys attracted more predators and experienced a higher likelihood of predation events in comparison to matching decoys, suggesting that camouflage mismatched animals experience increased detection by predators. These results provide insight into the function of a seasonal color coat and the need for this adaptation to maximize fitness in an environment that is exposed to high seasonality. Thus, our results suggest that, with increasing climate change and reduced snow cover, animals expressing a seasonal color coat will experience a decrease in survival.
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Affiliation(s)
- Pieter J Otte
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Joris P G M Cromsigt
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
- Department of Zoology, Centre for African Conservation Ecology, Nelson Mandela University, Gqeberha, South Africa
| | - Christian Smit
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Tim R Hofmeester
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
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5
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Charre‐Medellín JF, Ferrer‐Ferrando D, Monterrubio‐Rico TC, Fernández‐López J, Acevedo P. Using species distribution modeling to generate relative abundance information in socio-politically unstable territories: Conservation of Felidae in the central-western region of Mexico. Ecol Evol 2023; 13:e10534. [PMID: 37727774 PMCID: PMC10505758 DOI: 10.1002/ece3.10534] [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: 06/12/2023] [Revised: 08/30/2023] [Accepted: 09/04/2023] [Indexed: 09/21/2023] Open
Abstract
The distribution range and population abundance of species provide fundamental information on the species-habitat relationship required for management and conservation. Abundance inherently provides more information about the ecology of species than do occurrence data. However, information on abundance is scarce for most species, mainly at large spatial scales. The objective of this work was, therefore, to provide information regarding the population status of six wild felids inhabiting territories in Mexico that are inaccessible or politically unstable. This was done using species distribution models derived from occurrence data. We used distribution data at a continental scale for the wild felids inhabiting Mexico: jaguar (Panthera onca), bobcat (Lynx rufus), ocelot (Leopardus pardalis), cougar (Puma concolor), margay (Leopardus wiedii), and jaguarundi (Herpailurus yagouaroundi) to predict environmental suitability (estimated by both Maxent and the distance to niche centroid, DNC). Suitability was then examined by relating to a capture rate-based index, in a well-monitored area in central western Mexico in order to assess their performance as proxies of relative abundance. Our results indicate that the environmental suitability patterns predicted by both algorithms were comparable. However, the strength of the relationship between the suitability and relative abundance of local populations differed across species and between algorithms, with the bobcat and DNC, respectively, having the best fit, although the relationship was not consistent in all the models. This paper presents the potential of implementing species distribution models in order to predict the relative abundance of wild felids in Mexico and offers guidance for the proper interpretation of the relationship between suitability and population abundance. The results obtained provide a robust information base on which to outline specific conservation actions and on which to examine the potential status of endangered species inhabiting remote or politically unstable territories in which on-field monitoring programs are not feasible.
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Affiliation(s)
- Juan F. Charre‐Medellín
- National School of Higher StudiesUniversidad Nacional Autónoma de MéxicoMoreliaMexico
- Laboratory of Priority Terrestrial Vertebrates, Faculty of BiologyUniversidad Michoacana de San Nicolás de HidalgoMoreliaMexico
| | - David Ferrer‐Ferrando
- Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC‐UCLM‐JCCMCiudad RealSpain
| | - Tiberio C. Monterrubio‐Rico
- Laboratory of Priority Terrestrial Vertebrates, Faculty of BiologyUniversidad Michoacana de San Nicolás de HidalgoMoreliaMexico
| | | | - Pelayo Acevedo
- Instituto de Investigación en Recursos Cinegéticos (IREC), CSIC‐UCLM‐JCCMCiudad RealSpain
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Duarte HOB, Carvalho WD, de Toledo JJ, Rosalino LM. Big cats like water: occupancy patterns of jaguar in a unique and insular Brazilian Amazon ecosystem. MAMMAL RES 2023. [DOI: 10.1007/s13364-023-00681-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
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Blake Sasse D, Reifeiss JS, Perry RW. Increasing Detections of Small to Medium-Sized Mammals Using Multiple Game Cameras. SOUTHEAST NAT 2023. [DOI: 10.1656/058.022.0104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- D. Blake Sasse
- Arkansas Game and Fish Commission, 213A Highway 89 South, Mayflower, AR 72106
| | | | - Roger W. Perry
- Southern Research Station, US Forest Service, PO Box 1270, Hot Springs, AR 71902
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Sultaire SM, Millspaugh JJ, Jackson PJ, Montgomery RA. The influence of fine‐scale topography on detection of a mammal assemblage at camera traps in a mountainous landscape. WILDLIFE BIOLOGY 2022. [DOI: 10.1002/wlb3.01026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Sean M. Sultaire
- Wildlife Biology Program, W.A. Franke College of Forestry and Conservation, Univ. of Montana Missoula MT USA
| | - Joshua J. Millspaugh
- Wildlife Biology Program, W.A. Franke College of Forestry and Conservation, Univ. of Montana Missoula MT USA
| | | | - Robert A. Montgomery
- Wildlife Conservation Research Unit, Dept of Zoology, The Recanati‐Kaplan Centre, Univ. of Oxford, Tubney House Tubney Oxon UK
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Chaudhuri S, Rajaraman R, Kalyanasundaram S, Sathyakumar S, Krishnamurthy R. N-mixture model-based estimate of relative abundance of sloth bear ( Melursus ursinus) in response to biotic and abiotic factors in a human-dominated landscape of central India. PeerJ 2022; 10:e13649. [PMID: 36523470 PMCID: PMC9745790 DOI: 10.7717/peerj.13649] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 06/07/2022] [Indexed: 12/12/2022] Open
Abstract
Reliable estimation of abundance is a prerequisite for a species' conservation planning in human-dominated landscapes, especially if the species is elusive and involved in conflicts. As a means of population estimation, the importance of camera traps has been recognized globally, although estimating the abundance of unmarked, cryptic species has always been a challenge to conservation biologists. This study explores the use of the N-mixture model with three probability distributions, i.e., Poisson, negative binomial (NB) and zero-inflated Poisson (ZIP), to estimate the relative abundance of sloth bears (Melursus ursinus) based on a camera trapping exercise in Sanjay Tiger Reserve, Madhya Pradesh from December 2016 to April 2017. We used environmental and anthropogenic covariates to model the variation in the abundance of sloth bears. We also compared null model estimates (mean site abundance) obtained from the N-mixture model to those of the Royle-Nichols abundance-induced heterogeneity model (RN model) to assess the application of similar site-structured models. Models with Poisson distributions produced ecologically realistic and more precise estimates of mean site abundance (λ = 2.60 ± 0.64) compared with other distributions, despite the relatively high Akaike Information Criterion value. Area of mixed and sal forest, the photographic capture rate of humans and distance to the nearest village predicted a higher relative abundance of sloth bears. Mean site abundance estimates of sloth bears obtained from the N-mixture model (Poisson distribution) and the RN model were comparable, indicating the overall utility of these models in this field. However, density estimates of sloth bears based on spatially explicit methods are essential for evaluating the efficacy of the relatively more cost-effective N-mixture model. Compared to commonly used index/encounter-based methods, the N-mixture model equipped with knowledge on governing biotic and abiotic factors provides better relative abundance estimates for a species like the sloth bear. In the absence of absolute abundance estimates, the present study could be insightful for the long-term conservation and management of sloth bears.
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Affiliation(s)
- Sankarshan Chaudhuri
- Department of Landscape Level Planning and Management, Wildlife Institute of India, Dehradun, Uttarakhand, India
| | - Rajasekar Rajaraman
- Department of Landscape Level Planning and Management, Wildlife Institute of India, Dehradun, Uttarakhand, India
| | | | - Sambandam Sathyakumar
- Department of Endangered Species Management, Wildlife Institute of India, Dehradun, Uttarakhand, India
| | - Ramesh Krishnamurthy
- Department of Landscape Level Planning and Management, Wildlife Institute of India, Dehradun, Uttarakhand, India
- Faculty of Forestry, University of British Columbia, Vancouver, British Columbia, Canada
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10
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Evans BE, Mortelliti A. Forest disturbance and occupancy patterns of American ermine ( Mustela richardsonii) and long-tailed weasel ( Neogale frenata): results from a large-scale natural experiment in Maine, United States. J Mammal 2022. [DOI: 10.1093/jmammal/gyac079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Weasels are small mustelid carnivores that play an important role as predators of small mammals in a wide array of ecosystems. However, their response to land use, such as forest harvest for timber products, is seldom the subject of focused research and management projects. Both the American ermine, also known as the short-tailed weasel (Mustela richardsonii), and the long-tailed weasel (Neogale frenata) are native to Maine, United States, where commercial timber harvesting is widespread. The effects of this forest disturbance on weasels are poorly understood, so to contribute toward filling this knowledge gap, we conducted a 4-year, large-scale field study: specifically, our objective was to assess the effects of forest disturbance caused by timber harvest on occupancy patterns of ermines and long-tailed weasels occupancy patterns in Maine. We collected data from 197 survey sites (three camera traps each) over 4 years and analyzed over 7,000 images of weasels using dynamic false-positive occupancy models. We found that American ermines were widely distributed across the state (naïve occupancy at 54% of sites), while long-tailed weasels were rarer (naïve occupancy at 16% of sites). Both species responded positively to forest disturbance, with higher occupancy probabilities as disturbance increased, especially at the larger scales. American ermines were more likely to occupy stands with a higher percentage of conifer trees, while no such relationship was found for long-tailed weasels. We conclude that current forest harvest practices in Maine are not detrimental to weasel populations, but that the two species warrant continued monitoring.
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Affiliation(s)
- Bryn E Evans
- Department of Wildlife Fisheries and Conservation Biology, University of Maine , Orono, Maine , USA
| | - Alessio Mortelliti
- Department of Wildlife Fisheries and Conservation Biology, University of Maine , Orono, Maine , USA
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Morin DJ, Lesmeister DB, Nielsen CK, Schauber EM. Asymmetrical intraguild interactions with coyotes, red foxes, and domestic dogs may contribute to competitive exclusion of declining gray foxes. Ecol Evol 2022; 12:e9074. [PMID: 35813925 PMCID: PMC9251843 DOI: 10.1002/ece3.9074] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/05/2022] [Accepted: 06/08/2022] [Indexed: 11/07/2022] Open
Abstract
Species coexistence is governed by availability of resources and intraguild interactions including strategies to reduce ecological overlap. Gray foxes are dietary generalist mesopredators expected to benefit from anthropogenic disturbance, but populations have declined across the midwestern USA, including severe local extirpation rates coinciding with high coyote and domestic dog occurrence and low red fox occurrence. We used data from a large-scale camera trap survey in southern Illinois, USA to quantify intraguild spatial and temporal interactions among the canid guild including domestic dogs. We used a two-species co-occurrence model to make pairwise assessments of conditional occupancy and detection rates. We also estimated temporal activity overlap among species and fit a fixed-effects hierarchical community occupancy model with the four canid species. We partitioned the posterior distributions to compare gray fox occupancy probabilities conditional on estimated state of combinations of other species to assess support for hypothesized interactions. We found no evidence of broadscale avoidance among native canids and conclude that spatial and temporal segregation were limited by ubiquitous human disturbance. Mean guild richness was two canid species at a site and gray fox occupancy was greater when any combination of sympatric canids was also present, setting the stage for competitive exclusion over time. Domestic dogs may amplify competitive interactions by increasing canid guild size to the detriment of gray foxes. Our results suggest that while human activities can benefit some mesopredators, other species such as gray foxes may serve as bellwethers for habitat degradation with trophic downgrading and continued anthropogenic homogenization.
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Affiliation(s)
- Dana J. Morin
- Department of Wildlife, Fisheries and AquacultureMississippi State UniversityMississippi StateMississippiUSA
| | - Damon B. Lesmeister
- Pacific Northwest Research Station, U.S. Forest Service and Department of Fisheries and WildlifeOregon State UniversityCorvallisOregonUSA
| | - Clayton K. Nielsen
- Cooperative Wildlife Research Laboratory and Forestry ProgramSouthern Illinois UniversityCarbondaleIllinoisUSA
| | - Eric M. Schauber
- Illinois Natural History Survey, Prairie Research InstituteUniversity of Illinois Urbana‐ChampaignChampaignIllinoisUSA
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12
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Comparison of methods for estimating density and population trends for low-density Asian bears. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02058] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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13
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Griebling HJ, Sluka CM, Stanton LA, Barrett LP, Bastos JB, Benson-Amram S. How technology can advance the study of animal cognition in the wild. Curr Opin Behav Sci 2022. [DOI: 10.1016/j.cobeha.2022.101120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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14
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Perera P, Karawita H, Jayasinghe C. The applicability of camera trap data to monitor the cryptic Indian pangolin (Manus crassicaudata) populations: A survey from a tropical lowland rainforest in Southwest Sri Lanka. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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15
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Kays R, Hody A, Jachowski DS, Parsons AW. Empirical evaluation of the spatial scale and detection process of camera trap surveys. MOVEMENT ECOLOGY 2021; 9:41. [PMID: 34391486 PMCID: PMC8364038 DOI: 10.1186/s40462-021-00277-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Camera traps present a valuable tool for monitoring animals but detect species imperfectly. Occupancy models are frequently used to address this, but it is unclear what spatial scale the data represent. Although individual cameras monitor animal activity within a small target window in front of the device, many practitioners use these data to infer animal presence over larger, vaguely-defined areas. Animal movement is generally presumed to link these scales, but fine-scale heterogeneity in animal space use could disrupt this relationship. METHODS We deployed cameras at 10 m intervals across a 0.6 ha forest plot to create an unprecedentedly dense sensor array that allows us to compare animal detections at these two scales. Using time-stamped camera detections we reconstructed fine-scale movement paths of four mammal species and characterized (a) how well animal use of a single camera represented use of the surrounding plot, (b) how well cameras detected animals, and (c) how these processes affected overall detection probability, p. We used these observations to parameterize simulations that test the performance of occupancy models in realistic scenarios. RESULTS We document two important aspects of animal movement and how it affects sampling with passive detectors. First, animal space use is heterogeneous at the camera-trap scale, and data from a single camera may poorly represent activity in its surroundings. Second, cameras frequently (14-71%) fail to record passing animals. Our simulations show how this heterogeneity can introduce unmodeled variation into detection probability, biasing occupancy estimates for species with low p. CONCLUSIONS Occupancy or population estimates with camera traps could be improved by increasing camera reliability to reduce missed detections, adding covariates to model heterogeneity in p, or increasing the area sampled by each camera through different sampling designs or technologies.
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Affiliation(s)
- Roland Kays
- Department of Forestry and Environmental Resources, North Carolina State University, 2800 Faucette Drive, Raleigh, NC, USA.
- North Carolina Museum of Natural Sciences, 11 West Jones Street, Raleigh, NC, USA.
| | - Allison Hody
- Department of Forestry and Environmental Resources, North Carolina State University, 2800 Faucette Drive, Raleigh, NC, USA
- Department of Forestry and Environmental Conservation, Clemson University, 258 Lehotsky Hall, Clemson, SC, USA
| | - David S Jachowski
- Department of Forestry and Environmental Conservation, Clemson University, 258 Lehotsky Hall, Clemson, SC, USA
| | - Arielle W Parsons
- Department of Forestry and Environmental Resources, North Carolina State University, 2800 Faucette Drive, Raleigh, NC, USA
- North Carolina Museum of Natural Sciences, 11 West Jones Street, Raleigh, NC, USA
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16
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Hofmeester TR, Thorsen NH, Cromsigt JPGM, Kindberg J, Andrén H, Linnell JDC, Odden J. Effects of camera‐trap placement and number on detection of members of a mammalian assemblage. Ecosphere 2021. [DOI: 10.1002/ecs2.3662] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Tim R. Hofmeester
- Department of Wildlife, Fish, and Environmental Studies Swedish University of Agricultural Sciences Umeå SE‐90183 Sweden
| | - Neri H. Thorsen
- Norwegian Institute for Nature Research Sognsveien 68 Oslo NO‐0855 Norway
| | - Joris P. G. M. Cromsigt
- Department of Wildlife, Fish, and Environmental Studies Swedish University of Agricultural Sciences Umeå SE‐90183 Sweden
- Department of Zoology Centre for African Conservation Ecology Nelson Mandela University Port Elizabeth 6031 South Africa
- Copernicus Institute of Sustainable Development Environmental Sciences Utrecht University Utrecht 3548 The Netherlands
| | - Jonas Kindberg
- Department of Wildlife, Fish, and Environmental Studies Swedish University of Agricultural Sciences Umeå SE‐90183 Sweden
- Norwegian Institute for Nature Research PO Box 5685 Torgard Trondheim NO‐7485 Norway
| | - Henrik Andrén
- Department of Ecology Swedish University of Agricultural Sciences Grimsö Wildlife Research Station RiddarhyttanSE‐73993 Sweden
| | - John D. C. Linnell
- Norwegian Institute for Nature Research PO Box 5685 Torgard Trondheim NO‐7485 Norway
- Department of Forestry and Wildlife Management Inland Norway University of Applied Sciences Koppang NO‐2480 Norway
| | - John Odden
- Norwegian Institute for Nature Research Sognsveien 68 Oslo NO‐0855 Norway
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