The main danger to survival of the coastal California gnatcatcher is human activity. The diet of the coastal California gnatcatcher includes mostly insects. These were mostly by those against the delisting of the gnatcatcher. Thus continuing to make sure the Gnatcatcher is protected. It is an important habitat plant for the endangered California gnatcatcher. The adult tropical gnatcatcher is long, and weighs . This species is very similar to the California gnatcatcher and the black-tailed gnatcatcher. Switzer Canyon is a coastal sage scrub habitat that shelters the threatened California gnatcatcher. The coastal California gnatcatcher is the northernmost subspecies of the California gnatcatcher. A bird, the Iquitos gnatcatcher, "Polioptila clementsi", is named after him. It was previously considered a subspecies of the white-lored gnatcatcher. Many authorities consider it a subspecies of the Guianan gnatcatcher ("Polioptila guianensis"). The Coastal California Gnatcatcher lays on average 4 eggs at a time.