Understanding relationships between local-scale habitat structure and obligate grassland breeding bird (OGBB) abundance is important for management and conservation. Studies typically examine OGBB habitat relationships across a series of fields of different sizes and vegetation types. However, it may be difficult to elucidate effects of vegetation on OGBB abundance, due to the influence of patch size and perimeter/area ratio on this metric. Between 2006 and 2009, we examined relationships between OGBB abundance and vegetation in a 83 ha grassland at the John White Wildlife Management Area (JWWMA) in western New York, thereby removing area and related effects. The JWWMA has been managed primarily for OGBBs since 2005. The grassland, which is surrounded almost entirely by agricultural fields, contains ten smaller management units planted into different mixtures of native and nonnative cool season grasses, warm season grasses, and forbs. OGBB, which were counted using a variable-width transect method, generally were most abundant in management units with relatively low, less dense vegetation, and a mix of nonnative cool season grasses and forbs. Tall, dense stands of either cool season grasses and forbs, or the warm season grass Panicum virgatum, supported few OGBBs. Results of our study agree with other studies in the Northeast, which suggest that in most inland areas, OGBBs are most abundant in cool season grasslands with low, relatively less dense vegetation.
|Presenter:||Nathan Grosse (Graduate Student)|
|Time:||11 am (Session II)|