05/25/2026
In 2004, a National Geographic film crew working in Bakersfield, California found six dead San Joaquin kit foxes in a den near a mall parking lot. Two adults and four pups. Mall landscapers had filled the den entrances with dirt. The foxes suffocated underground.
Three years later, a new family of kit foxes moved into a den at the same site.
The San Joaquin kit fox is one of the most endangered mammals in North America. Fewer than five thousand remain. They have lost roughly ninety-two percent of their historic range across California's Central Valley to agriculture, oil extraction, and urban development. The grasslands and scrublands they evolved to hunt across have been converted into the most intensively farmed landscape in the Western Hemisphere. What remains of their natural habitat is fragmented into isolated patches separated by highways, canals, subdivisions, and industrial infrastructure.
The strange part of the story is that one of the largest and most stable kit fox populations in existence lives not in a nature reserve but inside the city of Bakersfield.
Bakersfield sits in the southern San Joaquin Valley, surrounded by oil fields, agriculture, and desert. The city itself is flat, dry, and sprawling, with large open lots, canal rights-of-way, drainage basins, golf courses, school campuses, and the kind of low-density suburban development that accidentally mimics the open terrain kit foxes need. The foxes moved in and stayed. California State University Bakersfield has a resident population on campus. Trail cameras set up by the university's biology department have captured footage of mothers and pups playing outside their dens between campus buildings at night.
A San Joaquin kit fox weighs about five pounds. It is one of the smallest canids in North America, with oversized ears that function as heat radiators in the desert and give the animal a face that looks more like a fennec fox than anything people associate with American wildlife. It hunts at night, moving fast and low across open ground, taking ground squirrels, pocket gophers, kangaroo rats, and insects. During the day it retreats underground into dens it either digs itself or takes over from ground squirrels. A single fox may use dozens of dens across its home range, rotating between them to avoid predators and parasites.
In urban Bakersfield, the dens are everywhere biologists have looked. Under parking lot landscaping islands. In the berms of drainage basins beside arterial intersections. Inside stacked pipe at construction sites. Under storage containers. In golf course fairways. Inside modular housing units. Brian Cypher of the Endangered Species Recovery Program at California State University Stanislaus has led urban kit fox research in Bakersfield for over two decades. His team has documented foxes denning in locations that no field guide would recognize as habitat. The foxes do not care what the surface looks like. They care what is underneath it. If the soil is soft enough to dig and the surface above offers enough quiet, the fox will den there.
The urban population thrived for years, in some measures outperforming wild populations in survival and reproductive rates. Then in 2013, sarcoptic mange appeared in the Bakersfield foxes and the population crashed. Sarcoptic mange is caused by burrowing skin mites and is always fatal in kit foxes. The disease spreads through direct contact and through shared dens, and Cypher's research published in 2025 showed exactly why the urban environment made it worse. Radio-collared foxes in Bakersfield used an average of nearly eight dens over a four-month period. Other foxes used the same dens within days. Some foxes were sharing dens simultaneously. In the urban landscape, where den density is high and foxes rotate through sites constantly, a single infected animal can seed mites across dozens of dens and expose nearly ten other foxes in a matter of months.
By 2022, Cypher's camera surveys detected no mange in the Bakersfield population, suggesting the epidemic had burned through and the survivors were rebuilding. But the population had been significantly reduced, and the genetic and demographic consequences of the crash are still being measured.
The kit foxes of Bakersfield represent something that conservation biology rarely produces: an endangered species that is doing better inside a city than outside it. The urban environment offers stable water from irrigation and canal systems, consistent prey populations sustained by human landscaping, reduced pressure from coyotes and bobcats that avoid developed areas, and an abundance of denning substrate in disturbed soils. The tradeoff is cars, dogs, pesticides, landscaping crews that do not check for dens before filling holes, and a disease transmission rate amplified by the same den-sharing behavior that makes the foxes successful in the first place.
A five-pound fox with satellite-dish ears hunting ground squirrels between the parking lot and the drainage ditch at a California state university campus is not the image most people carry of an endangered species. But the San Joaquin kit fox stopped matching the expected image decades ago. It adapted to the landscape humans built on top of its habitat, and it is raising pups in the infrastructure because the grasslands are gone and the infrastructure is what is left.
Source: Endangered Species Recovery Program, California State University Stanislaus / Cypher et al. (2025), Animals / U.S. Fish and Wildlife Service, San Joaquin Kit Fox 5-Year Review, 2025.
