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The California condor, 1966-1976: A Look at its Past and Future

North American Fauna No. 72

NTIS Accession Number: PB97-152821 PDF on file: 2156_Wilbur.pdf 5.9 MB
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Abstract

The California condor (Gymnogyps californianus) was studied on about 900 field days between 1966 and 1976. In addition, some 1,000 items of literature, specimen records from 56 museums, and 3,500 reports of condor sitings by cooperators were analyzed. Distribution does not appear to have changed significantly since the 1930's, although there are some areas within the. species' range that have become unusable. Two subpopulations of condors exist, one occupying the Coast Range Mountains, and the other found in the Transverse Ranges, Tehachapi Mountains, and Sierra Nevadas. There are well-defined seasonal movements within each subpopulation area. The surviving, wild population was estimated to be 45 condors in 1976, a decline of about 20% since 1965 and probably over 50% since 1940. No reliable population estimates are available before the 1940's, but it appears that a major decline occurred between 1880 and 1920. Shooting and specimen collecting were the primary causes of the early decline, and shooting continued as a major problem into the 1960's. Recent declines are a result of inadequate production; annual surveys indicate that only 16 young have been produced since 1968. Causes of low production are unknown but inadequate food supply, environmental contaminants, and disturbance from air traffic and petroleum extraction are implicated. A recovery plan for the condor is in operation; steps have been taken to supplement food supplies, preserve nesting and roosting habitat, and protect surviving birds from man-caused mortality or disturbance. The condor's prospects of recovery in its natural habitat seem bleak; a captive propagation program is proposed to supplement wild production.

Additional Publication Details

Publication type:
Report
Publication Subtype:
Federal Government Series
Title:
The California condor, 1966-1976: A Look at its Past and Future
Series title:
North American Fauna
Series number:
No. 72
Year Published:
1978
Language:
English
Publisher:
U.S. Fish and Wildlife Service
Contributing office(s):
Patuxent Wildlife Research Center
Description:
136