Faculty Research & Creative Activity

Document Type


Publication Date

January 2004


T.-Renesting decisions and annual fecundity are crucial for interpreting other demographic information, yet are infrequently reported. We used radiotelemetry to monitor female Dickcissels (Spiza americana) throughout the 1999 and 2000 breeding seasons in south- eastern Illinois. Overall fecundity (regardless of whether females remained in the study area throughout the breeding season) was 0.61 ? 0.13 female fledglings per year. Of females that re- mained within the study area, 94% fledged young (1.25 ? 0.15 female fledglings per year). Most females (62%) that experienced nest failure emigrated from the study area (moved >10 km) in 2.8 ? 0.6 days; others (36%) initiated subsequent nests in 8.5 ? 0.8 days. After fledging >1 young, 95% of females ceased breeding for the season. Successful and failed nest sites were indistin- guishable on the basis of vegetative characteristics. Moreover, replacement nests had similar vegetative characteristics and were similar distances from habitat edges, compared with initial nests, which suggests that female Dickcissels do not or cannot "improve" nest-site characteris- tics in response to nest failure. We observed two behaviors unusual in female Dickcissels: one bird that fledged two broods in one season, and the return of five females banded in 1999 to the study site in 2000.


Published as Renesting Decisions and Annual Fecundity of Female Dickcissels (Spiza americana) in Illinois Jeffery W. Walk, Kevin Wentworth, Eric L. Kershner, Eric K. Bollinger and Richard E. Warner The Auk Vol. 121, No. 4 (Oct., 2004) (pp. 1250-1261) Page Count: 12. © 2004 by the Regents of the University of California/American Ornithologists' Union. Copying and permissions notice: Authorization to copy this content beyond fair use (as specified in Sections 107 and 108 of the U. S. Copyright Law) for internal or personal use, or the internal or personal use of specific clients, is granted by the Regents of the University of California/on behalf of the American Ornithologists' Union for libraries and other users, provided that they are registered with and pay the specified fee via Rightslink® on [JSTOR (http://www.jstor.org/r/ucal)] or directly with the Copyright Clearance Center, http://www.copyright.com.