The Biology and Current Status of the Long-eared Owl in Coastal Southern California
The Long-eared Owl (Asio otus) is poorly known in southern California. This paper reviews its historic nesting distribution in Orange and western San Diego counties as determined from 79 egg set records from 5 museum collections, and contrasts this with the distribution of 50 nesting attempts as recorded in Orange and northern San Diego counties between 1968-1992. Comparisons reveal a substantial area of extirpation in the coastal region with a small, remnant population in interior areas. The number of historic breeding territories has de- creased by at least 55%. Reproduction appears good with 85% of 40 nests fledging young. Diet was typical of other regions with small rodents (Microtus calif ornicus, Reithrodontomys megalotis, and Thomomys bottae) comprising 90% of the prey by number.
Bloom, Peter H.
"The Biology and Current Status of the Long-eared Owl in Coastal Southern California,"
Bulletin of the Southern California Academy of Sciences:
Available at: https://scholar.oxy.edu/scas/vol93/iss1/5