![]() comm.) and the interior of a log out-building (J. Other less common nest sites include wells (Oberholser 1974), a fiberglass cistern and masonry bar-b-que pit (D. The bird’s necessity to cling to textured vertical surfaces when not in flight limits roost and nest sites to dark, hollow shafts such as masonry chimneys or airshafts of wood or brick. This indicates a late date for eggs no earlier than 28 July 1992.īREEDING HABITAT: Formerly nesting in hollow trees, the Chimney Swift now nests almost exclusively in man-made structures. ![]() A fallen nest with young aged two to six days was taken to licensed rehabilitators on 8 August 1992 in latilong 30097, quad C6 (Texas Parks and Wildlife Department Annual Species Report). Given an incubation period of 19 to 21 days (Sherman 1952, Fischer 1958), this indicates an early egg date of no later than 21 April 1987. The TBBAP data document a nest with young on at latilong 30099, quad A1. Oberholser notes that the early and late dates for eggs are May 5 and July 5, respectively. The breeding season for Chimney Swifts in Texas begins in late April (eggs) and continues into August (young on or around the nest). The presence of non-breeding spring and summer roosting flocks further complicates confirmation (Kyle and Kyle 1994). Because of the inaccessibility of most nest sites (usually deep, narrow shafts), only 36 of these confirmations resulted from the discovery of active nests with eggs or young. Of the 941 records obtained by the TBBAP, only 19% were confirmed. SEASONAL OCCURRENCE: Although the presence of Chimney Swifts is easy to establish by their vocal “chippering” and aerial displays, breeding is more difficult to confirm. Including the TBBAP data, only three possible records exist for the Trans-Pecos region (Wauer 1973, Oberholser 1974). The paucity of habitat (natural and man-made) in the Trans-Pecos region acts as a barrier to further expansion. Adapting to the historically new habitat of chimneys, air shafts and other structures instead of hollow trees, the Chimney Swift followed development westward across North America and Texas. With some additional frequency in western-most portions of its range, TBBAP data corroborate Oberholser’s observations of the bird.īoth the extension and limit of the range are directly related to human activity. Oberholser notes that in the 1950s and 1960s their breeding range had spread west and south but was still confined to the eastern two-thirds of Texas. By 1940 they were relatively common in Austin. It is the most common swift in the eastern half of the continent, and one of only two species of breeding swifts in Texas (Oberholser 1974).ĭISTRIBUTION: In 1925, Chimney Swifts were seldom seen in central Texas. The Chimney Swift is one of about 80 species worldwide and four that regularly occur in North America (Terres 1982).
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