eWestern Birds
The Quarterly Journal of Western Field Ornithologists
Declines in the Breeding Population of Vaux’s Swifts in Northeastern Oregon
Evelyn L. Bull
ABSTRACT: I investigated trends in the breeding population of Vaux’s Swift (Chaetura vauxi) in northeastern Oregon by revisiting in 2003 39 stands of trees that contained swifts in 1991. In 2003 the number of swifts in these stands was significantly fewer, with only 46% of the stands still containing swifts. Only 29% of the 58 nest and roost trees the swifts were using from 1989 to 1997 were still suitable for nesting in 2003; the remainder had fallen over, broken off, or become riddled with cavities. Factors that may be affecting the population include tree mortality caused by insect outbreaks and disease, tree harvesting, wildfire, climatic shifts, and habitat changes in the winter range.
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