(Montana State University - Bozeman, College of Agriculture, 2005) Marske, Katharine Ann; Chairperson, Graduate Committee: Michael A. Ivie.
The Montserrat Oriole, Icterus oberi Lawrence, endemic to the West Indian island of Montserrat, has grown critically endangered since volcanic eruption began on that island in 1995. The Soufriere Hills Volcano has devastated much of the oriole's native habitat, and populations within intact forests have plummeted in recent years. One hypothesized cause for the Montserrat Oriole's decline is that low insect prey numbers during the nesting season, as a result of volcanic ash in the environment, is resulting in increased nest failure. The hypothesis of a negative effect of ash on canopy arthropods was tested. Four sites, varying in the level of ash deposition they typically receive, were sampled via canopy fogging over a 14-month period. Results indicate that ash is having a significant negative impact on canopy arthropods, particularly at the sampling sites closest to the volcano, but that the decline is limited to a few insect taxa.
