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Range use and movements of California condors

Condor

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Abstract

Between 1982 and 1987, photographic and telemetric tracking of California Condors (Gymnogyps californianus) yielded information on use of the last known range of the species by 23 individual birds. Except for yearlings, most and possibly all individuals in the population used all major foraging zones. Use of the foraging zones was not uniform among individuals, however. Breeding pairs tended to forage most frequently in zones close to their nests (usually within 70 km, occasionally as far away as 180 km). Immatures (at least older immatures), unpaired birds, and paired birds that were not breeding foraged more widely. Male and female adults used the foraging range in a similar manner. Although most portions of the foraging range received some condor use throughout the year, use varied seasonally in accord with recent and historical patterns of food availability. Nesting areas were separated from foraging zones and were visited much less freely than foraging zones. Paired birds tended strongly to visit only their own and immediately adjacent nesting areas. Their nesting areas remained stable over the years. Unpaired adults and immatures ranged more widely among nesting areas. Condors were sometimes documented flying more than 200 km and traversing the entire range of the species during a day. Birds were variably social in movements. Pair members tended to stay together during long-distance travels. Immatures and unpaired birds sometimes traveled with other condors but often moved singly. In years when the population still included many breeders, the largest observed aggregations included one-half to two-thirds of the total population. The comparative strengths and weaknesses of photographic and telemetric methods are described for tracking and other research endeavors.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Range use and movements of California condors
Series title:
Condor
Volume
94
Issue:
2
Year Published:
1992
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
313-335
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
313
Last page:
335
Number of Pages:
23