Author: David Lawrence Evans
Publisher:
ISBN:
Category : Birds of prey
Languages : en
Pages : 76
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Book Description
Depletion of fisheries due to acid rain may pose a future threat to bald eagle and osprey populations in some regions. Loss of essential habitat has affected declines in the caracara and western burrowing owl and the disappearance of the norther aplomado falcon from the southern United States. Most populations of the ferruginous hawk, marsh hawk, and prairie falcon appear stable; habitat loss is the most critical factor in population changes.
Author: Curtice R. Griffin
Publisher:
ISBN:
Category : Bald eagle
Languages : en
Pages : 20
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Book Description
Bald eagles (Haliaeetus leucocephalus) associate with wintering waterfowl concentrations throughout the United States, but little detailed information is available on eagle-waterfowl relations. This report concerns the ecology of bald eagles wintering in the vicinity of Swan Lake National Wildlife Referenc in north-central Missouri and, more specifically, examines the association of the eagles with waterfowl during the winters of 1975-76, 1976-77, and 1977-78
Author: Leigh M. Couling
Publisher:
ISBN:
Category : Hunting surveys
Languages : en
Pages : 298
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Book Description
A mail questionnaire survey of waterfowl hunters is conducted each year in the United States to provide information on waterfowl kill and hunter activity. We carried out a study using data from the 1971-73 and 1972-73 hunting seasons to determine the effectiveness of the present U.S. sampling and estimation techniques, and a number of modifications in both sampling and analysis is recommended.
Author: Jerome H. Stoudt
Publisher:
ISBN:
Category : Bird populations
Languages : en
Pages : 40
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Book Description
A study of canvasback (Aythya valisineria) breeding populations, nest success, productivity, and habitat requirements was conducted from 1961 to 1972 on a 181.3 square kilometer area south of Minnedosa, Manitoba.
Author: Samuel M. Carney
Publisher:
ISBN:
Category : Hunting surveys
Languages : en
Pages : 120
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Book Description
Average numbers of waterfowl harvested during the 1971-80 hunting seasons are estimated by species for each county in the continental United States. A brief account of the estimating procedure is included.
Author:
Publisher:
ISBN:
Category : Fishery management
Languages : en
Pages : 136
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Book Description
Author:
Publisher:
ISBN:
Category : Wildlife conservation
Languages : en
Pages : 80
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Book Description
Author: U.S. Fish and Wildlife Service
Publisher:
ISBN:
Category : Fishes
Languages : en
Pages : 76
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Book Description
Author:
Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 380
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Book Description
Author:
Publisher:
ISBN:
Category : Birds
Languages : en
Pages : 48
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Book Description
One egg from each of 440 clutches of eggs of 19 species of Alaskan seabirds collected in 1973-76 was analyzed for organochlorine residues. Both frequency of occurrence and concentration of residues in the eggs differed geographically and by species, apparently reflecting non-uniform distribution of organochlorines in the environment, dissimilar feeding habits and migration patterns of the species, or metabolic differences among the species.
