Avian Community Ecology and the Shifting Baseline in Sugarcreek Metropark

Abstract

<p>Quantifying changes in forest avian diversity is a challenging, but necessary task for developing effective conservation plans. While small changes in diversity accumulate over time, short-term changes in communities do not allow us to assess changes in diversity. More progressive changes from established baseline conditions may be more interpretable because the changes in diversity are assessed over longer time periods. We examined the temporal changes in avian forest communities at Sugarcreek Metropark in southwestern Ohio based on baseline survey provided by Dr. Reed Noss. Working in 1978, Noss conducted 33 censuses during the breeding and postbreeding seasons and evaluated the diversity of the avifauna to discern trends in both composition and species richness (Noss 1981). Our objective of this study was to determine how forest avian diversity has changed in Sugarcreek Reserve (Metropark) over time and how those changes have altered species richness and community composition. In 1978, Noss observed 7,609 individuals representing 77 species. In 2010, we sampled with the same protocol and intensity, but only observed 6,445 individuals representing only 63 species. Rarefaction analysis was used to normalize 2010 data set to match 1978. Individual species were separated according to categories: wintering residents and migrants. Both rarefaction analysis and rank-abundance curves revealed declines in diversity were attributable to declines in migratory species. Numbers of Northern Cardinals (Cardinalis cardinalis) increased nearly threefold, and Indigo Bunting numbers (Passerina cyanea) declined by a third. The decline in migrants observed at Sugarcreek mirror declines of migrants elsewhere in eastern North America.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 8, 2011</p>