Document Type
Article
Publication Date
7-28-1971
Abstract
In 1969 Breeding Bird Survey cooperators ran 1,361 survey routes in all States except Hawaii and Alaska and all Canadian Provinces except Newfoundland. The average number of birds per route for each species is tabulated by States and Provinces, to show the comparative abundance across the continent. Weighted mean population values for selected species at the State, stratum, regional, and continental level are presented. In the Western Region there was a highly significant population decrease in the Red-winged Blackbird (99% level of probability); significant increases in the Western Meadowlark and Starling (95% level); and a decrease in the Turkey Vulture. In the Central Region there was a highly significant decrease in the Red-headed Woodpecker, and significant decreases in the Yellow Warbler and American Goldfinch. In the Eastern Region there was a highly significant increase in the Wood Thrush and a decrease in the American Goldfinch. An index for comparing populations of each species from year-to-year was established, with 1968 as the base year.
Recommended Citation
Van Velzen, Willet T. and Robbins, Chandler S., "Administrative Report: The Breeding Bird Survey, 1969" (1971). Research. 8.
https://digitalcommons.pittstate.edu/sperryresearch/8
