Factors Affecting Golden‐Cheeked Warbler Nest Survival in Urban and Rural Landscapes

Abstract

ABSTRACT We evaluated hypotheses concerning temporal, landscape, and habitat effects on nest survival of golden‐cheeked warblers (Dendroica chrysoparia) in an urban and a rural landscape during the breeding seasons of 2005 and 2006 in central Texas, USA. We found support for temporal effects of year and cubic effect of date and included them in candidate models that evaluated habitat and landscape effects. Nest survival was lower in 2006 than in 2005 and decreased nonlinearly as the breeding season progressed. We found support for edge effects with decreased nest survival nearer edges and in areas with increased open edge density (wooded habitat abutting open habitat) or decreased trail density. However, confidence intervals for the model‐averaged odds ratios overlapped 1.0 for all edge variables. Overall daily survival rate was 0.964 (95% CI = 0.949‐0.975), resulting in a 25‐day period survival of 0.398 (95% CI = 0.269‐0.524). Period survival in Austin's urban landscape (0.399, 95% CI = 0.270‐0.526) was similar to survival in Fort Hood's rural landscape (0.396, 95% CI = 0.261‐0.528). Both landscapes likely support self‐sustaining populations based on reasonable assumptions for adult survival and number of nesting attempts. We suggest that some large urban preserves can provide breeding habitat of comparable quality to rural locations and recommend protecting large parcels (>100 ha) of breeding habitat with limited fragmentation and reducing the amount of wooded edge abutting open habitat to ensure nest survival regardless of their landscape context.