Habitat use, nest success, and management recommendations for grassland birds of the Canaan Valley National Wildlife Refuge, West Virginia

Grassland bird populations have been declining due to increased habitat fragmentation, urbanization, and conversion of farmlands to other uses throughout the United States. However, idle hayfields and pastures in the eastern United States may provide adequate nesting habitat for grassland species displaced from their native habitat. The objectives of this study were to: (1) compare grassland bird abundance, diversity, and richness of species between 3 idle hayfields and 3 pastures and between mowed and unmowed treatments, and (2) compare grassland bird nest success between hayfields and pastures, and between mowed and unmowed treatments on the Canaan Valley National Wildlife Refuge, West Virginia during the summers of 1999--2000. A total of 27 species was found on the refuge. The predominant grassland species were bobolinks ( Dolichonyz oryzivorus), savannah sparrows (Passerculus sandwichensis ), and eastern meadowlarks (Sturnella magna). Overall bird abundance differed between mowed (x¯ = 0.61; SE = 0.09) and unmowed (x¯ = 0.32; SE = 0.06) treatments in pastures (P = 0.033). Grassland bird diversity differed between mowed plots of hayfields (x¯ = 0.85; SE = 0.21) and pastures (x¯ = 1.57; SE = 0.26) (P = 0.026). Mayfield nest survival did not differ between nests found in hayfields and pastures, and mowed and unmowed treatments. While nest success did not differ between mowed and unmowed treatments, mowing these fields at the conclusion of the breeding season will provide long team advantages to grassland birds nesting on the refuge. Additionally, grassland birds appeared to be responding to the vegetative structure and vertical diversity within fields rather than field size. Management should focus on removal of internal edges (i.e., remnant fencelines, hedgerows, and wind breaks) found throughout the grasslands on the refuge