Nocturnal singing in grassland birds

We conducted unlimited radius point counts from March-July 1999 at sunrise, dusk, and night to document the relative frequency of nocturnal singing by grassland birds at Prairie Ridge State Natural Area, Jasper County, Illino is. Most grassland species were recorded singing at all rimes of day. but l east commonly at night. Short-cared Owls (Asio flammeus) and American Woodc ock (Scolopax minor) were only recorded at dusk and night. Sedge Wrens (Cis tothorus platensis) and Henslow's Sparrows (Ammodramus henslowii) were most frequently recorded at night and least frequently at sunrise. Only 57% of all the breeding species recorded by our surveys were detected on June sunr ise counts corresponding to the timing of the North American Breeding Bird Survey.