Tuesday, July 22, 2014

Detection dogs and big cats

Greg Davidson and detection dog Chevy searching for cougar scat.

Detection dogs can be trained to locate explosives, illegal drugs, wildlife scat, or human remains. They have even been trained to locate illicit mobile phones in prisons. But, they have become extremely valuable for wildlife biologists and have been used to collect data on invasive species as well as endangered species.

In a forthcoming study in the Journal of Wildlife Management, Greg Davidson and colleagues from Find it Detection Dogs, used detection dogs to estimate the population size of cougars in northeast Oregon. Cougars are solitary, elusive, and have large home ranges. The researchers surveyed a 220 km2 area using conservation detection dogs trained to locate cougar scat. Two hundred and seventy-two scat samples were collected, and 249 were analyzed for individual identification using DNA.  From 73 samples, 21 cougars (9 males and 12 females) could be recognized. The authors evaluated four models to estimate cougar densities: Huggins closed population capture–recapture (Huggins), CAPWIRE, multiple detections with Poisson (MDP), and spatially explicit capture–recapture (SECR). Their population estimates for the study area were 26 (9 males and 17 females) from Huggins models, 24 (9 males and 15 females) from CAPWIRE, and 27 (9 males and 18 females) from the MDP model.

This study demonstrates the efficacy of using detection dogs to collect cougar scat. The results suggest the probability of a dog finding a cougar’s scat on the landscape (given scat was available) in any of the 4 surveys was 0.99 for males and 0.68 for females. As a result, the authors were able to collected scat from all 4 GPS-collared cougars known to occupy a portion of the study area. The reported capture probabilities of this study were the largest observed for any previous study conducted with wild felids, which highlight the benefits of using scat detecting dogs to estimate cougar densities. Determining the age of the cougars captured was not possible because of the use of scat; so, their estimates included adults, subadults, and juveniles old enough to leave den sites.

Citation

Davidson, G. A., Clark, D. A., Johnson, B. K., Waits, L. P., & Adams, J. R. (in press, 2014). Estimating cougar densities in northeast Oregon using conservation detection dogs. The Journal of Wildlife Management. DOI: 10.1002/jwmg.758

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