Assessing the Relationship Between Riparian Width and Neotropical Migrant Bird Species Richness in the middle Mississinewa Watershed, Indiana, USA
Date of Award
Master of Environmental Studies (MES)
Neotropical migratory birds have declined in recent decades due, in part, to loss of habitat and habitat fragmentation. Conservation organizations have set goals to reduce such declines and one goal in the Midwest is to determine minimum areas needed to support diverse populations of Neotropical migrants. My study focused on Neotropical migrant species richness in relation to the width of riparian corridor buffers. I surveyed 36 sites in three width categories (12 narrow, 12 medium, and 12 wide sites) along a ten-mile stretch of the Mississinewa River in North Central Indiana three times during the breeding season. As expected, my results showed a positive correlation between Neotropical species richness and riparian buffer width. Surprisingly, vegetative characteristics had little impact on species richness, although there was a weak correlation between species richness and the number of shrub species. This may be because riparian vegetation was fairly homogeneous and generally dense among my sample sites. Acadian Flycatcher and Wood Thrush were the most area-sensitive species encountered and my results suggested that > 450-m buffers are needed to support the full avian community in this region. Given the current land-use and agricultural practices in Indiana, however, widening riparian buffers to 100 m would protect the majority of Neotropical migrants, and could be a more practical conservation target.
Chapman, Mary B., "Assessing the Relationship Between Riparian Width and Neotropical Migrant Bird Species Richness in the middle Mississinewa Watershed, Indiana, USA" (2014). Master of Environmental Science Theses. 15.