Patterns of river otter (Lontra canadensis) diet and habitat selection at latrine sites in central British Columbia.

I investigated patterns in river otter (Lontra canadensis) diet, habitat selection, and behavior at latrine sites in central British Columbia during the ice-free season in 2007 and 2008. I used an Information Theoretic Model Comparison approach to investigate the relationships among otter diet and temporal/spatial parameters and habitat characteristics and the presence, consistency, and intensity of otter activity. Data were collected every two weeks at latrine sites visited by otters. I used a combination of scat content and stable-isotope analysis to investigate the contributions of different prey items to otter diet. Binary and count models were used to predict the presence of individual prey items and number of scats, respectively. A combination of fish spawning period, water body type, and individual lake best described the presence of salmonids, minnows, and insects in otter scat. The relative effects of season and water body varied considerably among the three prey groups found in scats. Scat deposition was positively influenced by a time period when no fish were spawning (early July) and to the kokanee (Oncorhynchus nerka) spawning period (early September). In general, the stable-isotope analysis agreed with the results of the scat content analysis showing a dominance of fish in the diet of otter and a small contribution from other prey sources. The stable-isotope analysis, however, suggested a larger contribution from sockeye salmon and birds relative to data from the scat content analysis. I followed the diet analyses with an investigation of factors that influenced the selection of latrine sites and activity of otter at multiple spatial and behavioural scales. For fine-scale analyses, I performed field measurements at latrine sites and spatially adjacent random sites. At the course landscape scale, I used Geographic Information Systems (GIS) to examine environmental variables that described the broader Tezzeron and Pinchi lake study area. Working at these two spatial scales, I used binary models to p