At the close of NBC's Nightly News on Dec. 1, there was an inspiring story about a small mammal brought back from the brink of extinction thanks to interest and action by conservation partners including the National Park Service (NPS), The Nature Conservancy (TNC) the U.S. Fish and Wildlife Service, as well as efforts by other groups and individuals.
That animal was the island fox (Urocyon littoralis)the smallest North American canid, (member of the dog family), weighing about five pounds. Found only on six of the largest Channel Islands, some 19 to 60 miles off the southern California coast, the native foxes were geographically isolated and believed to have been around for at least the last 15,000 years. The fox population on each island has unique characteristics and has its own subspecies.
The island fox is closely related to the gray fox (Urocyon cinereoargenteus) we have on the Texas South Plains. The gray fox is larger, weighing roughly 8 to 15 pounds. Unlike the red fox, also found in this area, the gray can climb easily, thanks to its strong, hooked claws. Foxes are primarily nocturnal, with peaks of activity around dawn and dusk.
The island foxes' homes had abundant tall, dense grasslands, and the foxes were at the top of the food chain, coexisting with resident bald eagles. It may not have been widely known at the time, but the territorial bald eagles prevented their cousins, the golden eagles, from coming in from the mainland. The bald eagles' diet was fish and they weren't intested in the small foxes.
However, when pigs were brought to the island in the mid-1800s, they ultimately attracted the attention of golden eagles, providing year-round fare for the goldens.
Something else was at play in the fragile ecosystem: When DDT was introducted in the 1950s, the bald eagle population crashed and as they were removed from the equation, goldens arrived again to fill the void.
Those elements, in combination with reduced grasslands, erosion and introduction of non-native fennel and other non-native plants, results in the foxes' being exposed to high predation rates.
By the 1990s, golden eagles were colonizing the islands, and island fox was on the menu, thereby shifting the foxes' status from predator to prey. Their habitat was further disrupted by introduced grazing sheep and the island foxes' numbers fell precipitously. Four island fox subspecies were placed on the Endangered Species List in 2004 when their numbers plummeted more than 95 percent.
Compounding these factors, a 1998 canine distemper outbreak killed many of the island foxes. Based on results of blood samples, the California Department of Fish and Game gave permission to test an experimental vaccine. All inoculated foxes survived and foxes given the vaccine successfully developed antibodies against canine distemper.
Scientists ultimately removed livestock, relocated the golden eagles to northeast California over a five-year period, reintroduced bald eagles and eventually reestablished the small foxes so they could become dominant once again. This took time, effort and about $5.4 million.
The end result was worth it.
Captive breeding programs for the foxes were established by the National Park Service in April, 1999. Experts determined golden eagle predation, disease and parasites as the most significant threats to the fox's survival. You can find a comprehensive report (2004) on the Island Fox Recovery Program on the Internet or visit a 2008 island-by-island update by visiting islandfox.org/pdfs/islandfoxupdate.pdf.
There's also a short two-page report including the use of radio tracking for island foxes at islandfox.org/pdfs/ifmgmtresearch.pdf.
That report says, in part, "Managing island fox populations has different challenges on different islands. Island fox recovery owes much of its success to the Island Fox Working Group and the sharing of information and strategies between the various land managers." There are also several video clips that weren't aired on television about the island fox that can be found at MSNBC under their Nightly News segments for Dec. 1.
The National Park Service calls the Channel Islands the "North American Galapagos because they are home to over 150 endemic, or unique, species."
The island fox's recovery was the fastest and most successful of any animal in history and appealed to me because it was a classic example of just how fragile many of nature's ecosystems are. With man's help instead of man's interference, the delicate balance can be successfully restored to a naturally functioning ecosystem.
CAROL LEE is the executive director emeritus of the South Plains Wildlife Rehabilitation Center, Inc. She can be reached at firstname.lastname@example.org.
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