Thanks to San Diego Zoo Global and the U.S. Navy, the San Clemente loggerhead shrike has been brought back from the brink of extinction. Listed as critically endangered in 1977 due primarily to loss of habitat from goats grazing on San Clemente Island, this subspecies of shrike has been the focus of a Navy-funded, intensive captive breeding and release program since 1991. Typically I spend my days in the Endocrinology Lab at the San Diego Zoo Institute for Conservation Research but was give the opportunity to visit the San Clemente Island Loggerhead Shrike Breeding Program for a day.
The shrike breeding facility is located about 10 miles south of the island’s airport (town). During our drive, I was struck by the lack of development. I can only imagine this is what San Diego looked like 100 years ago. I also imagined myself commuting to work every morning at 5 (they start early at the breeding facility!) on this small, two-lane road. Finally, we turned on a tiny dirt road that led to our destination. The facility is on the edge of a cliff about 1,300 feet above the ocean. It is quite impressive with arrays of breeding enclosures and a captive-rearing facility. The program has been very successful in breeding genetically valuable birds to help ensure the success of future generations.
The staff members make every attempt to parent-rear and cross foster baby birds, but in the event these attempts are not successful, they are fully prepared to artificially incubate eggs and hand raise baby birds. The loggerhead shrike program has been highly successful, with approximately 125 breeding individuals currently in the wild. This year alone, 30 fledglings were released to add to the 152 wild fledglings the previous year produced. The program has been deemed a success, and captive-breeding efforts may soon come to a halt if Navy-supported population biologists determine that the wild population could be self-sustaining.
I feel fortunate to have gotten an opportunity to experience San Clemente Island through the eyes of San Diego Zoo Global employees who spend their days trying to save the shrike from the brink of extinction. This experience opened my eyes to the hard work and dedication required for a successful captive-breeding program. It also introduced me to an illusive island right off San Diego’s coast. For that I am very appreciative. Thanks to San Diego Zoo Global and the U.S. Navy, the San Clemente loggerhead shrike has a bright and productive future!
Corinne Pisacane is a senior research laboratory technician for the San Diego Zoo Institute for Conservation Research. Read her previous post, Is Our Cheetah Pregnant?