The Biology and Current Status of the Long-eared Owl in Coastal Southern California

Abstract

The Long-eared Owl (Asio otus) is poorly known in southern California. <br /><br />This paper reviews its historic nesting distribution in Orange and western San <br /><br />Diego counties as determined from 79 egg set records from 5 museum collections, <br /><br />and contrasts this with the distribution of 50 nesting attempts as recorded in <br /><br />Orange and northern San Diego counties between 1968-1992. Comparisons reveal <br /><br />a substantial area of extirpation in the coastal region with a small, remnant <br /><br />population in interior areas. The number of historic breeding territories has de- <br /><br />creased by at least 55%. Reproduction appears good with 85% of 40 nests fledging <br /><br />young. Diet was typical of other regions with small rodents (Microtus calif ornicus, <br /><br />Reithrodontomys megalotis, and Thomomys bottae) comprising 90% of the prey <br /><br />by number.