|Title||Response of insectivorous birds to emerging aquatic insects in riparian habitats of a tallgrass prairie stream|
|Publication Type||Journal Article|
|Year of Publication||1993|
|Journal||American Midland Naturalist|
The relationship between emergence production of aquatic insects from Kings Creek, a tallgrass prairie stream, and densities of insectivorous birds (flycatcher and gleaner guilds) was examined using concurrent measurements of insect emergence and bird densities at six sites on 31 dates during May to July from 1987 to 1990. Daily insect emergence averaged 10.6 g/100-reach in the gallery forest habitat and 2.5 g/reach in the prairie/shrub habitat. Principal taxa included Chironomidae (>50% of emergence biomass), Ephemeroptera and Plecoptera. Common flycatchers were the eastern wood-pewee (Contopus virens) and great crested flycatcher (Myiarchus crinitus) in the gallery forest, and eastern kingbird (Tyrannus tyrannus) in the prairie/shrub habitat. Common gleaners were black-capped chickadee (Parus atricapillus) in the gallery forest and common yellowthroat (Geothlypis trichas) in the prairie/shrub. Flycatcher densities were highly correlated with total emergence in both habitats, but gleaner densities were correlated with emergence only in the gallery forest habitat. Both emergence and insectivore densities varied directly with the stream hydrograph, even over short, postflood recovery periods. Direct observations of feeding behavior showed that insectivores preyed upon a variety of aquatic and nonaquatic prey. Thus stream insects are an important food resource for insectivorous birds in riparian habitats of the tallgrass prairie, although insect emergence is likely insufficient to support observed insectivore densities.