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Recent trends in counts of migrant hawks from northeastern North America

Journal of Wildlife Management

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Abstract

Using simple regression, pooled-sites route-regression, and nonparametric rank-trend analyses, we evaluated trends in counts of hawks migrating past 6 eastern hawk lookouts from 1972 to 1987. The indexing variable was the total count for a season. Bald eagle (Haliaeetus leucocephalus), peregrine falcon (Falco peregrinus), merlin (F. columbarius), osprey (Pandion haliaetus), and Cooper's hawk (Accipiter cooperii) counts increased using route-regression and nonparametric methods (P < 0.05). Northern harrier (Circus cyaneus) counts increased based on the nonparametric method (P < 0.01) but not the route-regression method (P > 0.10). We found no consistent trends (P > 0.10) in counts of sharp-shinned hawks (A. striatus), northern goshawks (A. gentilis) red-shouldered hawks (Buteo lineatus), red-tailed hawks (B. jamaicensis), rough-legged hawsk (B. lagopus), and American kestrels (F. sparverius). Broad-winged hawk (B. platypterus) counts declined (P < 0.05) based on the route-regression method. Empirical comparisons of our results with those for well-studied species such as the peregrine falcon, bald eagle, and osprey indicated agreement with nesting surveys. We suggest that counts of migrant hawks are a useful and economical method for detecting long-term trends in species across regions, particularly for species that otherwise cannot be easily surveyed.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Recent trends in counts of migrant hawks from northeastern North America
Series title:
Journal of Wildlife Management
Volume
54
Issue:
3
Year Published:
1990
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
463-470
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Journal of Wildlife Management
First page:
463
Last page:
470
Number of Pages:
8