Type: other

Article abstract: We conducted periodic occupancy surveys for coastal California gnatcatcher (Polioptila californica californica) from 2004 - 2009 in the San Diego County, focusing on preserve lands associated with Habitat Conservation Plans. We investigated the effects of habitat quality classification, elevation, distance to coast, and heat load on the occupancy, extinction, and colonization probabilities. In addition a wildfire in 2003 burned 17,044 hectares, roughly 1/3 of the area, thus we were able to investigate the recolonization process associated with this unforeseen event. We found that occupancy increased with habitat quality and over time, but decreased with elevation. Extinction probability was at a generally constant rate (~0.13), but colonization varied greatly with probabilities being higher in higher quality habitat and at lower elevations. We suggest that sites categorized as high and very high quality at lower elevations should receive priority in terms of conservation actions. Although the burned plots are starting to be recolonized, after 5 years post-burn, these areas are not at pre-burned occupancy levels and monitoring should continue.