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Endangered Species Make Comeback on San Clemente Island
Endangered Species Make Comeback on San Clemente
San Clemente Island (SCI) is home to six plant species, four wildlife species, two marine invertebrates, all which are currently federally listed as “endangered” or “threatened” in addition to numerous other native and sensitive species.
The wildlife that are endangered and threatened on SCI include the endemic San Clemente loggerhead shrike, western snowy plover, San Clemente Bell’s sparrow (formerly the San Clemente sage sparrow), island night lizard and island fox (which is state but not federally endangered).
In the early 1990s, the San Clemente loggerhead shrikes were documented at an all-time population low, and in 1998 the population dipped to just 14 wild birds. This bird is a subspecies of the mainland loggerhead shrike and only lives at San Clemente Island.
San Clemente Island has an extensive shrike recovery program in place, which consists of predator management, habitat enhancement, captive breeding, release, and population monitoring. Through the Navy’s recovery efforts, the number of loggerhead shrikes has grown to 68 breeding pairs in 2013.
In 1977, the San Clemente Island bush mallow was one of the first plants listed under the Endangered Species Act. Found only on San Clemente Island, only one individual was known at the time of listing. After decades of recovery, there are now thousands of these lavender-flowered plants across much of the island.
Catalina grass, which historically was found on Santa Catalina Island, San Clemente Island, and Guadalupe Island, was believed to be extinct, as the plant hadn’t been seen since 1913. However the plant was recently rediscovered on Santa Catalina Island, and rediscovered on San Clemente Island in 2010. San Clemente now supports roughly 1,000 individuals of this unique plant.
San Clemente Island broom and San Clemente Island paintbrush are found only on San Clemente Island. These two plants were also some of the first plants listed under the Endangered Species Act. Just two decades ago, only a few hundred individuals of each of these species existed. Now each of these species has tens of thousands of individuals. The recovery of these two species is so significant that the United States Fish and Wildlife Service (USFWS) down-listed these two species from “endangered” to “threatened” in August 2013.
The Navy took the first big step toward recovering native wildlife and plants by removing feral goats and pigs that were destroying the island’s ecosystem. Approximately 30,000 goats were taken off the island, with the final goats removed in the early 1990’s.
Today, thanks to the Navy’s wildlife and botanical management programs, animals and native plants are showing signs of remarkable recovery, and program costs are decreasing. The San Clemente Bell’s sparrow has dramatically expanded its range and numbers following the recovery of native vegetation once nearly absent due to over grazing by goats. Navy botanist, Bryan Munson explained, “The return of the native plant life is expanding the populations of the native animals.”
Through habitat restoration, erosion control, and invasive species control, the Navy’s management efforts have helped transform San Clemente Island. Grasslands, scrublands, and woodlands have covered this once nearly barren island. Sensitive plant and animal species, like the San Clemente Bell’s sparrow, have increased dramatically as their habitats have recovered across the island.
One surprising fact that Navy biologists have monitored is the resiliency shown by certain plants and animals to the Navy training operations. Shrikes can be found successfully nesting in the Impact Area and have persisted and expanded there for many years. The federally endangered San Clemente Island bush mallow, a fire-adapted species, thrives within the Shore Bombardment Area.
The Navy has owned San Clemente Island since 1934 and began to work toward native ecosystem recovery in the late 1970s. The endangered island night lizard was delisted on May 1, 2014, based on species recovery. San Clemente Island now has the highest recorded density of any lizard on earth, an estimated 21.3 million island night lizards. Scientists are seeing plants and animals slowly creeping out of caves and canyon bottoms and spreading out across the savannas that had been decimated by the feral goats. Some places that resembled cratered moonscapes are now covered with native shrubs so thick it’s hard to wade through them.
The Navy not only manages four federally listed species, but has successfully managed and maintained all species endemic to the island. The Navy manages these species so that their populations are robust and do not warrant inclusion under the Endangered Species Act allowing the Navy to carry out its primary mission of national security at sea. ¦