Interdisciplinary Seminar
Successes and limitations of occupancy modeling: a tale of two taxa in the Greater Yellowstone Ecosystem

William Gould, Applied Statistics Program, New Mexico State University, USA

Two monitoring programs were developed as a means for monitoring ecosystem health in Yellowstone and Grand Teton National Parks. Annual surveys for breeding occupancy by amphibians using temporal replication were conducted over years 2006-2009. Multi-season occupancy estimation was used to assess changes in the occurrence of tiger salamanders, boreal chorus frogs and Columbia-spotted frogs at two scales: small watershed (catchment) and individual site. Landbird monitoring has also been conducted (primarily in Grand Teton National Park) in which point count surveys were used to detect landbirds in different habitats. Density was estimated using distance methodology, but occupancy rates were also estimated using spatial replication from multiple points along surveyed transects. The sampling designs, modeling approaches, and results of these two programs will be presented. Differences between study designs and the resulting effect on occupancy estimation will be discussed.

Em 11.05.2012
Anfiteatro 4 (Colégio Luís António Verney, U.Évora)