Imperiled foxes on Santa Cruz Island will likely go extinct unless the National Park Service removes golden eagles, a protected species, through bold means, perhaps even shooting them, a new study concludes.
Such a draconian step may be necessary because the eagles have eaten so many of the diminutive foxes that the animals are spiraling toward extinction, three experts write in an article appearing today in the journal Science.
The article crystallizes some of the stark ethical questions that face society as greater numbers of rare animals and plants worldwide compete for survival.
"Conservation of species threatened with imminent extinction may require drastic measures that can be emotionally charged, politically unsavory and legally challenging," the biologists wrote.
The eagles also threaten fox subspecies on two neighboring islands -- Santa Rosa and San Miguel -- where attempts are underway to save the foxes from extinction, said one of the paper's authors, UC Davis conservation biologist Rosie Woodroffe.
Park Service officials said this week that they have not determined that golden eagles must be destroyed, and that any such decision would require considerable study. Making the task even more difficult, the three fox subspecies are candidates for protection under the Endangered Species Act while the golden eagle is protected by two other federal acts.
The three fox subspecies exist nowhere else in the world. Each island has seen its population of foxes plummet precipitously since the eagles -- for reasons not entirely clear -- began colonizing them in the early 1990s.
On Santa Cruz Island, the fox population dropped from about 1,500 to fewer than 100 in less than a decade. So few foxes remained in the wild on Santa Rosa and San Miguel islands that biologists decided to bring them into captivity in hopes of saving them.
Breeding programs are underway on all three islands and, just two weeks ago, a handful of foxes were released on Santa Cruz and Santa Rosa.
The foxes are biologically distinct from the rare foxes on Santa Catalina Island, where 10 captive-bred animals were released into the wild Tuesday. To date, golden eagles have not settled on Catalina or preyed on the foxes there.
Santa Rosa, San Miguel and part of Santa Cruz Island are part of Channel Islands National Park, where park scientists have been struggling to restore native animals and vegetation by removing nonnative species. Since 1999, biologists working for the park have relocated 31 golden eagles to northeastern California.
