A model to predict breeding-season productivity for multibrooded songbirds

Citation
La. Powell et al., A model to predict breeding-season productivity for multibrooded songbirds, AUK, 116(4), 1999, pp. 1001-1008
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences
Journal title
AUK
ISSN journal
0004-8038 → ACNP
Volume
116
Issue
4
Year of publication
1999
Pages
1001 - 1008
Database
ISI
SICI code
0004-8038(199910)116:4<1001:AMTPBP>2.0.ZU;2-9
Abstract
Breeding-season productivity (the per capita number of offspring surviving to the end of the breeding season) is seldom estimated for multibrooded son gbirds because of cost and logistical constraints. However, this parameter is critical far predictions of population growth rates and comparisons of s easonal productivity across geographic or temporal scales. We constructed a dynamic, stochastic, individual-based model of breeding-season productivit y using demographic data from Wood Thrushes (Hylocichla mustelina) in centr al Georgia from 1993 to 1996. The model predicts breeding-season productivi ty as a function of adult survival, juvenile survival, nesting success, sea son length, renesting interval, and juvenile-care intervals. The model pred icted 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, nestin g success, fledglings per successful nest, and adult and juvenile survival caused variation in breeding-season productivity. Contrary to commonly held notions, season length and fledgling-care interval length did not cause va riation in breeding-season productivity. This modeling exercise emphasizes the need for demographic data for songbird species, and we encourage biolog ists to use similar models to evaluate productivity in songbird populations .