Physical and Environmental Geography Commons^™

Modelling Pinniped Abundance And Distribution By Combining Counts At T Terrestrial Sites And In-Water Sightings, Steven L. Whitlock, Jamie N. Womble, James T. Peterson

United States National Park Service: Publications

Pinnipeds are commonly monitored using aerial photographic surveys at land- or ice-based sites, where animals come ashore for resting, pupping, molting, and to avoid predators. Although these counts form the basis for monitoring population change over time, they do not provide information regarding where animals occur in the water, which is often of management and conservation interest. In this study, we developed a hierarchical model that links counts of pinnipeds at terrestrial sites to sightings-at-sea and estimates abundance, spatial distribution, and the proportion of time spent on land (attendance probability). The structure of the model also allows for the inclusion …