Modelling density surfaces of intraspecific classes using camera trap distance sampling
Abstract Spatially explicit densities of wildlife are important for understanding environmental drivers of populations, and density surfaces of intraspecific classes allow exploration of links between demographic ratios and environmental conditions. Although spatially explicit densities and class de...
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Format: | Article |
Language: | English |
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Wiley
2023-05-01
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Series: | Methods in Ecology and Evolution |
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Online Access: | https://doi.org/10.1111/2041-210X.14093 |
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author | Zackary J. Delisle David L. Miller Robert K. Swihart |
author_facet | Zackary J. Delisle David L. Miller Robert K. Swihart |
author_sort | Zackary J. Delisle |
collection | DOAJ |
description | Abstract Spatially explicit densities of wildlife are important for understanding environmental drivers of populations, and density surfaces of intraspecific classes allow exploration of links between demographic ratios and environmental conditions. Although spatially explicit densities and class densities are valuable, conventional design‐based estimators remain prevalent when using camera‐trapping methods for unmarked populations. We developed a density surface model that utilized camera trap distance sampling data within a hierarchical generalized additive modelling framework. We estimated density surfaces of intraspecific classes of a common ungulate, white‐tailed deer Odocoileus virginianus, across three large management regions in Indiana, United States. We then extended simple statistical theory to test for differences in two ratios of density. Deer density was influenced by landscape fragmentation, wetlands and anthropogenic development. We documented class‐specific responses of density to availability of concealment cover, and found strong evidence that increased recruitment of young was tied to increased resource availability from anthropogenic agricultural land use. The coefficients of variation of the total density estimates within the three regions we surveyed were 0.11, 0.10 and 0.06. Synthesis and applications. Our strategy extends camera trap distance sampling and enables managers to use camera traps to better understand spatial predictors of density. Our density estimates were more precise than previous estimates from camera trap distance sampling. Population managers can use our methods to detect finer spatiotemporal changes in density or ratios of intraspecific‐class densities. Such changes in density can be linked to land use, or to management regimes on habitat and harvest limits of game species. |
first_indexed | 2024-03-12T20:33:14Z |
format | Article |
id | doaj.art-6030febafa2945969f432a86a50345fb |
institution | Directory Open Access Journal |
issn | 2041-210X |
language | English |
last_indexed | 2024-03-12T20:33:14Z |
publishDate | 2023-05-01 |
publisher | Wiley |
record_format | Article |
series | Methods in Ecology and Evolution |
spelling | doaj.art-6030febafa2945969f432a86a50345fb2023-08-01T18:55:36ZengWileyMethods in Ecology and Evolution2041-210X2023-05-011451287129810.1111/2041-210X.14093Modelling density surfaces of intraspecific classes using camera trap distance samplingZackary J. Delisle0David L. Miller1Robert K. Swihart2Department of Forestry and Natural Resources Purdue University West Lafayette Indiana USABiomathematics and Statistics Scotland Dundee ScotlandDepartment of Forestry and Natural Resources Purdue University West Lafayette Indiana USAAbstract Spatially explicit densities of wildlife are important for understanding environmental drivers of populations, and density surfaces of intraspecific classes allow exploration of links between demographic ratios and environmental conditions. Although spatially explicit densities and class densities are valuable, conventional design‐based estimators remain prevalent when using camera‐trapping methods for unmarked populations. We developed a density surface model that utilized camera trap distance sampling data within a hierarchical generalized additive modelling framework. We estimated density surfaces of intraspecific classes of a common ungulate, white‐tailed deer Odocoileus virginianus, across three large management regions in Indiana, United States. We then extended simple statistical theory to test for differences in two ratios of density. Deer density was influenced by landscape fragmentation, wetlands and anthropogenic development. We documented class‐specific responses of density to availability of concealment cover, and found strong evidence that increased recruitment of young was tied to increased resource availability from anthropogenic agricultural land use. The coefficients of variation of the total density estimates within the three regions we surveyed were 0.11, 0.10 and 0.06. Synthesis and applications. Our strategy extends camera trap distance sampling and enables managers to use camera traps to better understand spatial predictors of density. Our density estimates were more precise than previous estimates from camera trap distance sampling. Population managers can use our methods to detect finer spatiotemporal changes in density or ratios of intraspecific‐class densities. Such changes in density can be linked to land use, or to management regimes on habitat and harvest limits of game species.https://doi.org/10.1111/2041-210X.14093abundancedeerdensity surface modellinggeneralized additive modelprecisionrecruitment |
spellingShingle | Zackary J. Delisle David L. Miller Robert K. Swihart Modelling density surfaces of intraspecific classes using camera trap distance sampling Methods in Ecology and Evolution abundance deer density surface modelling generalized additive model precision recruitment |
title | Modelling density surfaces of intraspecific classes using camera trap distance sampling |
title_full | Modelling density surfaces of intraspecific classes using camera trap distance sampling |
title_fullStr | Modelling density surfaces of intraspecific classes using camera trap distance sampling |
title_full_unstemmed | Modelling density surfaces of intraspecific classes using camera trap distance sampling |
title_short | Modelling density surfaces of intraspecific classes using camera trap distance sampling |
title_sort | modelling density surfaces of intraspecific classes using camera trap distance sampling |
topic | abundance deer density surface modelling generalized additive model precision recruitment |
url | https://doi.org/10.1111/2041-210X.14093 |
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