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Effects of abundant species on the ability of observers to make accurate counts of birds

The Auk

By:
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Abstract

Bird numbers can be estimated using a variety of methods (Emlen 1971, Berthold 1976, Reynolds et al. 1980). The number of birds counted is frequently reported in relation to some measure of effort: e.g. per unit area, per count period, per observer day, or per km of trail. The numbers recorded are sometimes those of only a single species (Kepler and Kepler 1973, Mayfield 1973, Van Riper et al. 1978), but more frequently the numbers of all species encountered are recorded. In 16 of 18 articles in which estimated numbers of birds were reported in the 1973-1978 issues of The Auk and The Condor, observers recorded all birds encountered. In the other two studies, the numbers of only one species were estimated. The stated or implicit assumption in those studies reporting all species is that there is no loss of information with the added responsibility of keeping track of a larger number of species. The ability of a single person to record accurately all individuals and species has been challenged by Carney and Petrides (1957), Lack (1976), and Preston (1979). The question is: Are the data recorded by an observer who must record all species (generalist) less accurate than those recorded by an individual who has the responsibility for recording only a subset of the community (specialist)?

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Effects of abundant species on the ability of observers to make accurate counts of birds
Series title:
The Auk
Volume:
98
Issue:
3
Year Published:
1981
Language:
English
Publisher:
American Ornithological Society
Contributing office(s):
Patuxent Wildlife Research Center
Description:
4 p.
First page:
610
Last page:
613