WHITE-HEADED WOODPECKER (PICOIDES ALBOLARVATUS) NESTING HABITAT SELECTION: ARE THEY MAKING GOOD CHOICES?
Kathryn L. Purcell; US Forest Service, Pacific Southwest Research Station; 2081 E. Sierra Avenue, Fresno, CA, 93710; (559) 916-4634; kpurcell@fs.fed.us; Eric McGregor, Jim Baldwin
We studied white-headed woodpeckers (Picoides albolarvatus) in the Sierra Nevada, California and collected data on nesting habitat at three spatial scales. Habitat selection models at the nest site and 125-ha scales best predicted white-headed woodpecker nest occurrence. At the nest site scale, white-headed woodpeckers nested in areas with open canopy, fewer large trees, more snags, and in more decayed substrates compared to random plots but no variables were important for nest survival. At the 1-ha scale, white-headed woodpeckers nested in areas with more conifers and fewer snags but again no variables were important for nest survival. At the 125-ha scale, models for habitat selection and nest survival were in agreement. Nests were found and were more successful in areas of higher canopy cover of conifers with high edge density. Viewed across multiple spatial scales, white-headed woodpeckers selected heterogeneous landscapes. At nest sites they selected areas with low canopy cover while at the home range scale they selected and were more successful within forests of moderate canopy cover and high edge density. Taken together, our results suggest white-headed woodpeckers nest in areas with access to decayed snags, forest openings, and moderate canopy cover at the landscape scale.
Ecology and Conservation of Birds II