IS THE CALIFORNIA GNATCATCHER AN INDICATOR OF BIRD-SPECIES RICHNESS IN COASTAL SAGE SCRUB?

Abstract

In southern California, the California Gnatcatcher (Polioptila californica) is a year-round resident in coastal sage scrub (Atwood 1993). This habitat—reduced to 10 to 30% of its former extent due to conversion to human use—supports approximately 100 other animal and plant species considered rare, sensitive, threatened, or endangered by California or federal wildlife agencies (Atwood 1993, McCaull 1994).