Population trends of forest birds in Missouri, USA: Comparison of point count data with predictions from the BBS [abstract]

Abstract only availableLong-term population size trends of Neotropical migrants and other forest birds are of primary concern for conservation biologists. The Breeding Bird Survey (BBS) has become an important tool for biologists in estimating population trends, but because surveys are conducted only along roads, its utility for forest interior species may be limited. We analyzed a long term (1991-2006) point count data set from the interior of three forested sites in central Missouri and compared our trend estimates to BBS trends for the state of Missouri. Using a mixed model analysis of variance with year as a fixed effect and point as a random effect, we generated trend estimates for thirteen species. Results/Conclusions Five species (38%) exhibited statistically significant negative trends indicating species decline, four species (31%) exhibited positive trends indicating that populations increased, three species (23%) exhibited no significant trend, and data from one species did not adequately fit the model. Of the nine species with significant trends in our point count data, seven (78%) had trends that were qualitatively similar to those generated from BBS data. However, for both of the species with contrasting trends, model predictions were strongly different. Our results suggest that the accuracy of BBS trends for forest interior birds may be species specific. We hope to strengthen our conclusions by incorporating point count data from other field sites and by controlling for observer effects in future analyses.NSF Undergraduate Mentoring in Environmental Biolog

What nest condition tells us about predators and nest success for birds [abstract]

Abstract only availableSince the 1990's scientists have become concerned about the declining population of migratory birds. A reduction in available habitat in wintering grounds and stop-over sites during migration may contribute to the decline in migratory bird populations. Another hypothesis for this decline in population is overwhelming nest predation on breeding grounds. This may be due to forest fragmentation which increases depredation of nests. Even though we understand why landscapes affect the bird population, knowledge of what types of predators are affected by fragmentation would determine how to manage land effectively. In this study, I test the hypothesis that nest condition would predict predator types by the amount of damage caused to the nest. To do this I found and monitored nests in Missouri and took pictures from different angles. I then set up video cameras to monitor the nest continuously. Once a nest failed, I took pictures to compare to the earlier ones. I will be scoring nests based on categories 0-3, which are based on the percentage change in nest condition from original photos