A medium-sized swallow (17 to 20 g), with long forked tail. Steely-blue upperparts, ruforus underparts, and chestnut forehead. Sexes are similar, but males have longer outer tail-streamers than females. Juveniles are similar to adults (Brown and Brown 1999).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
Western Hemisphere Range
In the Bozeman area, migration periods are May 1 to 15 and August 25 to September 10.
Originally nesting primarily in caves, it has almost completely converted to breeding under the eves of or inside artificial structures such as buildings and bridges. Presently found in various habitats, including agricultural areas, cities, suburbs, and along highways. Breeding habitat usually contains open areas (fields and meadows) for foraging, a nest site that includes a vertical or horizontal substrate underneath some type of roof and ceiling and a body of water that provides mud for nest building (Brown and Brown 1999).
Main food is flying insects (Brown and Brown 1999).
Near Fortine, egg dates for the first brood are May 20 to August 4 and egg dates for the second brood are July 4 to August 27. Statewide, nest building is in late June with hatching in mid-July.