Nocturnal Predation of Females on Nests: An Important Source of Mortality for Golden-checked Warblers?

We monitored 124 female Golden-checked Warblers (Dendroica chrysoparia) at 133 nests with video cameras from 1997-2002 and 2005-2006 at two study areas in central Texas, USA. Six adult females were depredated by snakes in 781 camera-monitored intervals when females were on the nest at night and exposed to possible nocturnal predation. Daily nest survival was 0.971 (95% CI: 0.959-0.980) and daily adult female predation while nesting was 0.008 (95% CI: 0.003-0.017). We estimated that 14.6% of breeding females were depredated on the nest during the breeding season based on the observed survival rates and assuming females whose first nest was unsuccessful and which survived attempted a second nesting attempt. Females were captured 75% of the times they were on the nest at the time of a nocturnal nest predation by a snake. Predation of nesting females is potentially an important source of mortality for Golden-checked Warblers, and warrants further investigation. Received 7 June 2008. Accepted 30 August 2008.