Darwin’s Fox: The Rarest In South America (NPR)
Monday, October 25th, 2010—
Darwin’s fox (Lycalopex fulvipes) is having a hard time finding refuge. Only a few hundred of the squat, dark-coated foxes survive today in the remaining patches of temperate rainforest that once stretched along the entire coast of southern Chile. Much of their habitat has been destroyed, or replaced with pine and eucalyptus groves, and there is another, more hounding, concern.
“The main threat seems to be the leashless domesticated dogs that are very abundant and live all over southern Chile,” says Jaime Jiménez, an ecologist at the Universidad de los Lagos in Osorno, Chile. “Even the park rangers have dogs.”
He says the foxes that aren’t chased and killed by loose dogs are susceptible to parasites the dogs carry as well as viral diseases like rabies and distemper.
The foxes take cover in the rainforest that remains, eating everything from small mammals and birds to crustaceans and insects. Scientists have verified two separate populations: one on the island of Chiloé (from which they get their Spanish name, zorro chilote) and one about 300 miles north in Nahuelbuta National Park.
Morphology and Ecology
Darwin’s fox is morphologically distinct from its cousin, which is only found on mainland Chile, the chilla fox (Lycalopex griseus); Darwin’s fox has shorter legs, a darker coat and a broader head. But since they are about the same size, scientists had classified it as a subspecies of the chilla fox until a study in 1996 deemed it a genetically distinct species. They diverged from a common ancestor more than 275,000 years ago.
Charles Darwin was the first scientist to describe the fox when he saw it on the island of Chiloé in 1834.
“According to Darwin,” recounts Jiménez, “when he returned from a geological excursion and saw the rare fox keenly observing the Beagle’s mariners on the beach, he crept up behind it and hit it over the head with his geological hammer.”
Jiménez says he could get just as close to the foxes while he was studying their behavior and numbers on Chiloé. He published a paper on their ecology in the Journal of Zoology in 2007.
It’s been three years since park rangers last saw Darwin’s foxes in Nahuelbuta National Park, says Agustín Iriarte, an ecologist with the non-profit conservation group Flora and Fauna Chile who has been studying their range and numbers for over 14 years. He has optimistic news: a few days ago, Chile’s forestry service CONAF announced four new sightings of Darwin’s foxes in the areas abutting Nahuelbuta National Park.
Jiménez says the larger of the two fox populations is on Chiloé, estimating it to be comprised of about 70 foxes. This low number has earned the species the designation ‘critically endangered’ on the IUCN (International Union for the Conservation of Nature) Red List of Threatened Species.
Jiménez says that no one knows exactly how many foxes are left, and that’s why he’s involved in continually trapping, radiotagging and tracking them. He also says it’s very difficult to secure financing for his conservation efforts. What little funding he has comes from a miscellany of international sources, from Brookfield Zoo in Chicago to the Darwin Initiative in the United Kingdom.
“Their numbers do not exceed 400 individuals,” says Jiménez. “This makes them one of the most critically endangered mammals on the planet — more than panda bears and blue whales.”
—Aleszu Bajak, NPR’s ‘Science Friday’