Abstract
Camera traps have become an important research tool for both conservation biologists and wildlife managers. Recent advances in spatially explicit capture-recapture (SECR) methods have increasingly put camera traps at the forefront of population monitoring programs. These methods allow for benchmark analysis of species density without the need for invasive fieldwork techniques. We conducted a review of SECR studies using camera traps to summarize the current focus of these investigations, as well as provide recommendations for future studies and identify areas in need of future investigation. Our analysis shows a strong bias in species preference, with a large proportion of studies focusing on large felids, many of which provide the only baseline estimates of population density for these species. Furthermore, we found that a majority of studies produced density estimates that may not be precise enough for long-term population monitoring. We recommend simulation and power analysis be conducted before initiating any particular study design and provide examples using readily available software. Furthermore, we show that precision can be increased by including a larger study area that will subsequently increase the number of individuals photo-captured. As many current studies lack the resources or manpower to accomplish such an increase in effort, we recommend that researchers incorporate new technologies such as machine-learning, web-based data entry, and online deployment management into their study design. We also cautiously recommend the potential of citizen science to help address these study design concerns. In addition, modifications in SECR model development to include species that have only a subset of individuals available for individual identification (often called mark-resight models), can extend the process of explicit density estimation through camera trapping to species not individually identifiable.
Highlights
Camera Traps and Benchmarking BiodiversityHuman-induced changes to both terrestrial and marine ecosystems are intensifying, especially in areas of the world with historically high levels of biodiversity (Venter et al, 2016)
Camera traps have been used for population monitoring for decades
Spatially-explicit mark recapture (SECR) methods make it possible to accurately estimate density over a given area, eliminating the need for ad hoc approaches like estimating individual movement through the maximum distance traveled across camera stations or applying an arbitrary buffer around the camera trap array
Summary
Camera Traps and Benchmarking BiodiversityHuman-induced changes to both terrestrial and marine ecosystems are intensifying, especially in areas of the world with historically high levels of biodiversity (Venter et al, 2016). Human activities have a direct effect on biodiversity, altering ecosystems around the globe (Cardinale et al, 2006; Estes et al, 2011; Hooper et al, 2012) During this period of rapid change, and in order to better understand the effects of human activity on biodiversity, it has become increasingly important to provide baseline measurements of species distributions and population sizes, especially for rare, elusive, and difficult-to-monitor species like carnivores, which play important roles in regulating ecosystems (Beschta and Ripple, 2009; Laundre et al, 2010; Ripple et al, 2014). Camera traps have become powerful research tools for scientists and wildlife managers investigating a wide variety of ecological questions, management situations, and conservation strategies (Karanth and Nichols, 1998; and Glen and Dickman, 2003; Hirakawa, 2008; O’Connell et al, 2011; Meek et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
