Grassland songbirds have been declining due to loss of habitat. In Canaan Valley, WV, grassland habitats primarily consist of active and idle pastures and hayfields. Our objectives were to document the species of breeding birds that occurred on grasslands of the Canaan Valley National Wildlife Refuge and evaluate temporal patterns of abundance among months and years. This study took place on 3 idle hayfields and 3 idle pastures in the Refuge during the summers of 1999 and 2000. At the conclusion of the first field season, half of each field was mowed. A total of 28 species—13 in 1999 and 27 in 2000—was documented. Dolichonyx oryzivorus (Bobolink), Sturnella magna (Eastern Meadowlark), Passerculus sandwichensis (Savannah Sparrow), and Agelaius phoeniceus (Red-winged Blackbird) were dominant. Additional species observed included Ammodramus savannarum (Grasshopper Sparrow) and Circus cyaneus (Northern Harrier). Species diversity, species richness, and total bird abundance varied among months (P < 0.05). Densities were higher in July than in May, June, and August; however, total number of birds peaked later in 1999 than in 2000. Species richness and diversity were lower in August than other months. Temporal variations in grassland bird diversity, richness, and abundance were likely influenced by precipitation patterns and land-use practices on and adjacent to the Refuge.