Individual identification of wild giant pandas from camera trap photos – a systematic and hierarchical approach

The scientific and conservation-management value of using camera traps is greatly enhanced if the identity of individual animals 'captured' can be assigned. Identification of individuals is necessary to make unbiased estimates of population parameters, and can allow for the generation of more robust inferences from studies of spatial and behavioral ecology. Here we tested the utility of an approach to individually identify wild giant pandas Ailuropoda melanoleuca from camera trap images, by cataloguing and careful scrutiny of numerous traits. We developed our identification strategy first by analyzing images of known (captive) individuals (N = 7). We then deployed camera traps at 23 control sites and at seven camera trap arrays 'baited' with conspecific decoys, in Foping Nature Reserve, China. From a sample of 12 871 photographs, and using the method we developed with known individuals, we were able to identify 11 individual giant pandas. We tested the repeatability of this approach using a double blind test with 12 naive volunteers, achieving a relatively high inter-observer agreement of 80%, which was increased to 93% when observers reported a high degree of confidence. We also found that image quality was significantly higher at decoy sites than at control sites. We suggest that this approach will be useful for future field projects, allowing researchers to address a broader array of questions and provide new insights into panda ecology and conservation.