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A model to predict breeding-season productivity for multibrooded songbirds

Auk

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Abstract

Breeding-season productivity (the per capita number of offspring surviving to the end of the breeding season) is seldom estimated for multibrooded songbirds because of cost and logistical constraints. However, this parameter is critical for predictions of population growth rates and comparisons of seasonal productivity across geographic or temporal scales. We constructed a dynamic, stochastic, individual-based model of breeding-season productivity using demographic data from Wood Thrushes (Hylocichla mustelina) in central Georgia from 1993 to 1996. The model predicts breeding-season productivity as a function of adult survival, juvenile survival, nesting success, season length, renesting interval, and juvenile-care intervals. The model predicted that seasonal fecundity (number of fledglings produced) was 3.04, but only 2.04 juveniles per female survived to the end of the breeding season. Sensitivity analyses showed that differences in renesting interval, nesting success, fledglings per successful nest, and adult and juvenile survival caused variation in breeding-season productivity. Contrary to commonly held notions, season length and fledg-ling-care interval length did not cause variation in breeding-season productivity. This modeling exercise emphasizes the need for demographic data for songbird species, and we encourage biologists to use similar models to evaluate productivity in songbird populations.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
A model to predict breeding-season productivity for multibrooded songbirds
Series title:
Auk
Volume
116
Issue:
4
Year Published:
1999
Language:
English
Contributing office(s):
Patuxent Wildlife Research Center
Description:
1001-1008
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
1001
Last page:
1008
Number of Pages:
8