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
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...
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PeerJ Inc.
2022-12-01
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| Online Access: | https://peerj.com/articles/13649.pdf |
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| author | Sankarshan Chaudhuri Rajasekar Rajaraman Sankar Kalyanasundaram Sambandam Sathyakumar Ramesh Krishnamurthy |
| author_facet | Sankarshan Chaudhuri Rajasekar Rajaraman Sankar Kalyanasundaram Sambandam Sathyakumar Ramesh Krishnamurthy |
| author_sort | Sankarshan Chaudhuri |
| collection | DOAJ |
| description | 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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| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T07:00:20Z |
| publishDate | 2022-12-01 |
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| spelling | doaj.art-a6a4cfdc97ce44cab8af949bb5223a702023-12-03T09:53:06ZengPeerJ Inc.PeerJ2167-83592022-12-0110e1364910.7717/peerj.13649N-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 IndiaSankarshan Chaudhuri0Rajasekar Rajaraman1Sankar Kalyanasundaram2Sambandam Sathyakumar3Ramesh Krishnamurthy4Department of Landscape Level Planning and Management, Wildlife Institute of India, Dehradun, Uttarakhand, IndiaDepartment of Landscape Level Planning and Management, Wildlife Institute of India, Dehradun, Uttarakhand, IndiaSalim Ali Centre for Ornithology and Natural History, Coimbatore, Tamil Nadu, IndiaDepartment of Endangered Species Management, Wildlife Institute of India, Dehradun, Uttarakhand, IndiaDepartment of Landscape Level Planning and Management, Wildlife Institute of India, Dehradun, Uttarakhand, IndiaReliable 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.https://peerj.com/articles/13649.pdfSloth bearRelative abundanceCamera trapN-mixture modelHuman-dominated landscape |
| spellingShingle | Sankarshan Chaudhuri Rajasekar Rajaraman Sankar Kalyanasundaram Sambandam Sathyakumar Ramesh Krishnamurthy 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 Sloth bear Relative abundance Camera trap N-mixture model Human-dominated landscape |
| title | 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 |
| title_full | 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 |
| title_fullStr | 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 |
| title_full_unstemmed | 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 |
| title_short | 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 |
| title_sort | 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 |
| topic | Sloth bear Relative abundance Camera trap N-mixture model Human-dominated landscape |
| url | https://peerj.com/articles/13649.pdf |
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