San Joaquin Kit Fox - Randy Sterbentz

San Joaquin Kit Fox

Vulpes macrotis mutica

Randy Sterbentz

Description and Ecology:

San Joaquin Kit Fox

(https://www.nwf.org/News-and-Magazines/National-Wildlife/Animals/Archives/2004/Poisoning-the-Imperiled.aspx)

            The kit fox (Vulpes macrotis) is the smallest species of fox on Earth.  The San Joaquin subspecies (Vulpes macrotis mutica) is the largest of the kit fox species, growing to around 31.7 inches.  There are only two subspecies of kit fox that are recognized: the species that lives in the San Joaquin Valley and the species that lives elsewhere (Vulpes macrotis macrotis).  Mercure et al. determined that the kit foxes living in San Joaquin Valley had distinct habits compared to other kit foxes, therefore classifying it as a subspecies of its own. (2)

           

            San Joaquin kit foxes can have a tan, buff, or greyish-silver coat, with a white or tan underbelly.  They have a distinct black tip on their tail.  Their tail is bushy and long (11 inches), and is typically carried down and straight. (2)

(http://www.mnn.com/earth-matters/animals/stories/one-glimpse-of-these-baby-kit-foxes-and-youll-be-hooked-on-their-story)

            They are decent diggers, modifying California ground squirrels’ burrows to accommodate for their larger size.  San Joaquin kit fox populations in an area vary wildly.  During child-rearing, families can move 3-5 times a month.  At 4 months of age, male San Joaquin kit fox pups will start to disperse to start hunting on their own.  Females may stick with their mother for up to a year.  After 1 year, the kit foxes can reproduce, though they rarely do in the first year of maturity. (1)

            San Joaquin kit foxes are predators, and as such, they help control populations of their prey.  Being nocturnal, they typically hunt nocturnal rodents, as well as San Joaquin antelope squirrels, desert cottontails, ground-nesting birds, insects, and even grass. (2)

Geographic and Population Change:

Current Range of the San Joaquin Kit Fox

(http://lpfw.org/our-region/wildlife/san-joaquin-kit-fox/)

            Historically, the San Joaquin kit fox used to prowl the entire San Joaquin Valley.  Their range has now been reduced to the edge of the Valley, from southern Kern County, up to Contra Costa County. Pre-1930, it is estimated there used to be as many as 12,134 kit foxes in the Valley.  As of 1975, it’s estimated there were 6,961 kit foxes in the reduced range.  The majority of San Joaquin kit foxes currently live in the southern edge of their range, with 41% of the population in Kern County and 10% in San Luis Obispo County. (2)

(http://www.littleredmillinery.com/kit-fox-diet/)

List Date: Federal: 1967 (California: 1971)

Listing Status: Federal: Endangered (California: Threatened)

Cause of listing and Main Threats:

            With the increased human development that has gone on in the San Joaquin Valley, the natural environment for all San Joaquin Valley inhabitants is being degraded.  Roads are fragmenting populations of kit fox, preventing them from reaching one another.  Developing the land is causing collapses on kit fox dens, suffocating the foxes still inside.  Grazing lands are being used up by livestock, degrading the habitat of the kit fox’s prey. (1)

Rodenticides are also impacting their survivability, either by directly ailing them when they consume a poisoned rodent, or by there not being as abundant of a source of rodents as they’re being killed off.  In addition to human causes, other species such as the red fox and coyotes compete with the San Joaquin kit foxes for the dwindling resources. (2)

All of these causes are resulting in the endangerment of the San Joaquin kit fox.  The largest of these concerns is their habitat fragmentation.  Without the ability for populations to interact with each other, they will die off separately. (1)

Description of Recovery Plan:

            The primary goal of the recovery plan is to secure the populations in three core areas: the Carrizo Plain Natural Area in San Luis Obispo County; Natural land of western Kern County; and the Ciervo-Panoche Natural Area of western Fresno and eastern San Benito Counties.  These lands are key locations that help keep the San Joaquin community thriving.  For the kit foxes, they serve as cornerstones that allow satellite populations to exist nearby and still have somewhere to return to safely.  There are many satellite populations that exist between these core populations, creating a network of sorts connecting the core populations.  If a core population goes extinct, that dramatically reduces success for the other core populations.  These are also mostly public lands, which puts less of a burden on private land owners.  Maintaining these lands and ensuring their sustainability will benefit not only the kit fox, but also all species that claim these lands as their home. (2)

            A secondary objective is more research.  Very little is known about the San Joaquin kit fox: an accurate historical range/population, agricultural abilities, distribution, interactions with Red foxes, etc.  Surveys will be performed alongside restoration efforts so more information can be gathered to better future recovery plans. (2)

What Can You Do?:

            If you don’t happen to have millions of dollar laying around to purchase some public land to personally protect, there are some small things you can do if live nearby the Valley.  San Joaquin kit foxes are adaptable, so if an urban environment comes to them, they can adapt to being scavengers.  Reduce the use of rodenticides, seal trash bags so kit foxes cannot get into them, and avoid attracting rodents and squirrels to your home.  Many other instances can be found in the site linked in Other Resources. (3)

Other Resources:

            Visit this site to inform yourself on how to prevent harming San Joaquin kit foxes:

https://www.wildlife.ca.gov/Keep-Me-Wild/Kit-Fox

(http://tinmanphotoblog.com/10-reasons-why-everyone-should-do-wildlife-photography/)

Bibliography:

1)  “Keep Me Wild: Kit Fox”. CA.gov. 2016. Web. December 1, 2016.

2)  “San Joaquin Kit Fox”.  Defenders of Wildlife. 2016. Web. November 28, 2016.

3)  Williams, Daniel F., et al., “Recovery Plan for Upland Species of the San Joaquin Valley, California.” U.S. Fish and Wildlife Service. 1998. Web. November 28, 2016.