Population Decline of the Island Loggerhead Shrike (Lanius ludovicianus anthonyi) in the California Channel Islands

Abstract

The Island Loggerhead Shrike (Lanius ludovicianus anthonyi) is classified as a species of special concern by the California Department of Fish and Game. We conducted a breeding bird census of Loggerhead Shrikes on Santa Cruz Island in 2006 based on potential shrike habitats identified using remote sensing. Census results for 2006, along with additional findings, constitute the first quantitative and replicable assessment of the subspecies' status. Population size is <30 birds with 12 on Santa Cruz Island and 15 on Santa Rosa Island. These observations, coupled with comparable surveys on other northern Channel Islands, provide the basis for a species and habitat conservation management plan.