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Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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At least 145 records · Page 8Linked to original sources
USGS1966

Selected bibliography on the red-winged blackbird

Lists alphabetically, by author, 128 informative references on the life history, biology, economic status, and control of the re-winged blackbird (Agelaius phoeniceus). A brief description is given for those reference titles that do not clearly indicate the content of the paper.

Special Scientific Report - Wildlife↗
USGS1979

Human related mortality of birds in the United States

Modern man serves as both a direct and an indirect cause of the death of birds. In the early 1970's, human activity was responsible for the death of approximately 196 million birds per year, or about 1.9% of the wild birds of the continental United States that died each year. Hunting was the largest direct mortality factor and accounted for about 61% of human related bird deaths. Control or prevention of avian depredations took about 1% of the total, and all research and propagation about 0.5%. Collision with man-made objects was the greatest indirect human cause of avian deaths. accounting for about 32% of the human related deaths. Pollution and poisoning caused the death of about 2% of the total. A relatively few species account for most of this mortality but continue to maintain large, harvestable populations, suggesting that the numbers of most bird species are essentially unaffected by the human activities discussed. Other activities of man that do not necessarily result in the death of birds but rather reduce reproductive potential are more likely to have long-term effects on avian populations.

Special Scientific Report - Wildlife↗
USGS1973

Birds imported into the United States in 1971

Birds imported into the United States in 1971 are tabulated by species. Total numbers for the period 1968-1971 are given for the more commonly imported taxa. The number of birds imported in 1971 increased only slightly over that for.1970. In 1971, 750 species were imported, of which 194 had not been imported in the previous 3 years; since 1968, approximately 1,445 species have been imported. Parrots accounted for nearly 25 percent of all birds imported in 1971, compared to only 13.5 percent in 1970. Birds were imported from 63 foreign countries, but more than 90 percent of all birds came from only 10 countries. The proportion of imported birds presumed to have been raised in captivity decreased in 1971.

Special Scientific Report - Wildlife↗
USGS1967

The breeding bird survey, 1966

A Breeding Bird Survey of a large section on North America was conducted during June 1966. Cooperators ran a total of 585 Survey routes in 26 eastern States and 4 Canadian Provinces. Future coverage of established routes will enable changes in the abundance of North American breeding birds to be measured. Routes are selected at random on the basis of one-degree blocks of latitude and longitude. Each 241/2-mile route, with 3-minute stops spaced one-half mile apart, is driven by automobile. All birds heard or seen at the stops are recorded on special forms and the data are then transferred to machine punch cards. The average number of birds per route is tabulated by State, along with the total number of each species and the percent of routes and stops upon which they were recorded. Maps are presented showing the range and abundance of selected species. Also, a year-to-year comparison is made of populations of selected species on Maryland routes in 1965 and 1966.

Special Scientific Report - Wildlife↗