Using spatial capture-recapture models to estimate spotted hyaena (Crocuta crocuta) population density and assess the influence of sex-specific covariates on space use and detection probability.
Description
Despite being resident or reintroduced to multiple South African protected areas, spotted hyaena (Crocuta crocuta) have been subject to limited population monitoring and are not managed in the same intensive way as other large carnivores. Considering the species’ significant influence on ecosystem processes, robust estimates of population density are necessary to inform conservation management. In this study, we ran a single-season camera trap survey in the Main Camp section of Addo Elephant National Park (Addo), South Africa, and used spatial capture-recapture (SCR) models to estimate spotted hyaena population density. Spotted hyaena density was estimated to be 11.13 (± SE 1.96) individuals/100 km2, with an estimated abundance of 37 (± SE 6.44). Using our database of sexed spotted hyaena individuals, we found no significant difference for sex-specific SCR parameters (baseline encounter probability and spatial scale parameter), suggesting the incorporation of sex-specific information may not be as necessary for spotted hyaena as it is for territorial felids and other species with more pronounced differences in range size. Spotted hyaena density in Addo was comparable to previous SCR studies and towards the higher end of known densities. Our estimate provides an important baseline for monitoring reintroduction success in Addo, and we advocate for increased SCR monitoring of spotted hyaena in South African protected areas to inform a metapopulation approach to the species’ management. These data include spotted hyaena capture histories and metadata (_edf and _tdf files) for SCR analysis of spotted hyaena density in Addo Elephant National Park, South Africa. We test the effects of distance to den site, camera type and sex on baseline encounter probability and space use. We include R code which covers step by step analysis and associated instructions. GPS locations of camera traps can be obtained by contacting the authors directly with prior written permission from SANParks due to the sensitivity of such locations in their priority species monitoring program. Original R Code supplied by author Dr Robert S. Davis
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Steps to reproduce
We implemented one single season camera trap survey for 46 days in Addo Main Camp from 23 January 2023 till 13 March 2023. The survey used 34 single camera trap stations, with a combination of white flash (Cuddeback Digital, Green Bay, USA) and infrared (Bushnell Trophy Cam HD; Bushnell Corporation, Overland Park, KS, USA) camera traps deployed. We identified individual spotted hyaena from camera trap images using their unique spot patterns and prepared the data for SCR analysis by creating capture history files and camera metadata files (the associated _tdf and _edf files).