Despite centuries of cattle ranching and farming, wild animals are
still to be found in California's San Joaquin Valley. One such is a
diminutive, big-eared fox, which has only two speeds: fast and
faster. This subspecies, known as the San Joaquin kit fox, is
hanging on not only in protected areas but in highly developed
areas such as Bakersfield, digging their dens as close as ten feet
to a house.
The foxes have a taste for fast food and are always available for handouts. Where they can, they stick with the old ways, however. Their diet includes lizards, mice and rats, ground squirrels, mourning doves, snakes and beetles. Some have learned to open the traps in which biologists catch kangaroo rats for tagging. The kit foxes are preyed on in turn by coyotes and recently introduced red foxes.
No one knows how many are left, but the number is far lower than the 7,000 that scientists estimated lived in California as recently as 1975. Only 5 percent of the fox's original habitat remains. Brian Cypher is studying the urban foxes for the Endangered Species Recovery Program. Katherine Ralls of the Smithsonian's Conservation and Research Center is doing the same in the Carrizo Plain National Monument, where a glimpse of presettlement California can be seen. Their research will provide information on the genetics, behavior, distribution and population size, that can be applied to the little carnivore's conservation.
Nothing can protect them from the vagaries of nature. When a drought occurs, plants don't produce seeds and kangaroo rats run out of food and don't reproduce. As their populations, along with those of other rodents drop, so too do the numbers of kit foxes. Without enough to eat, they stop reproducing as well. Heavy rains can have the same impact.
Ralls and her colleagues have a new ally in their research: a dog. Scat from foxes and all other animals contains some of the animal's DNA in cells from the lining of the intestines. Samples are analyzed at the Smithsonian's molecular genetics lab at the National Zoo. "We'll eventually be able to establish paternity, family groups, related and unrelated individuals," says Jesús Maldonado, who does the work. But how to distinguish kit fox scat from that of other animals? It turns out that dogs can be trained to detect the scat of a particular species and ignore everything else.
All of the San Joaquin kit foxes are in jeopardy. "We've already learned a lot through our cumulative research," says Ralls. "But there's still a lot more to find out if this species is to make it."