Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582530
Title: Improving the reliability of jaguar abundance and density estimates from camera trapping surveys
Author: Higginbottom, Paul Andrew
Awarding Body: Manchester Metropolitan University
Current Institution: Manchester Metropolitan University
Date of Award: 2012
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Abstract:
Population estimates of jaguar (Panthera onca) are important for conservation strategies such as ruCN classification, tracking population trends and establishing protected areas. Estimates produced using camera traps can suffer from a lack of reliability due to the spatial and temporal variations that are possible when deploying camera grids in the field. This PhD examined factors that influence jaguar abundance and density estimates produced from camera trap surveys, and how estimates could be improved upon. The Cockscomb Basin Wildlife Sanctuary, Belize, an area known to support a healthy jaguar population was chosen as the study site. Closed models and a Bayesian spatially explicit capture-recapture (SECR) method were examined. First, camera trapping was modified to produce closed model estimates from areas without trails. Second, temporal issues of survey length, timing and population openness, and spatial factors such as camera density and location were investigated. Finally, performance ofthe SECR method was compared with closed models, and questions of sample size, survey timing and location sensitivity examined. Camera trapping of Neotropical cats is rarely performed in areas without trails. A modified strategy was proposed which placed cameras only on watercourses, and results compared with a concurrent trail-based survey. Jaguar densities were higher on watercourses than on trails (watercourses: 10.4 ± 3.75 S.E.; trails: 6.4 ± 1.50 S.E. jaguars 100 km"). Capture rates of jaguar and ocelot (Leopardus pardalis) did not differ between areas, but were lower on watercourses for puma (Puma coneolor). Watercourse cameras recorded higher jaguar capture rates than those on new trails, suggesting that watercourses be preferred when positioning cameras. Jaguar capture rates were lower during the day on trails, but not on watercourses, and trapping success was improved by placing cameras where sign had been detected, and where surrounding gradients were steepest. The strategy proved appropriate for jaguar and ocelot, and is recommended for future studies in areas without trails. Most camera trap studies of big cats are one-off surveys that vary in length. Survey timing and length, and population closure were investigated as factors that may compromise the reliability of abundance estimates, with estimates generated from surveys of different start times and lengths. For longer durations, estimates were constant until a transient period was encountered where they became higher (> 3 x) and less stable.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.582530  DOI: Not available
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