The San Joaquin Kit Fox

Written by Kinser Coelho

Description and Ecology

Do you know what the largest subspecies of small, North American foxes in California is? If you guessed the San Joaquin Kit Fox, you are absolutely right! It was named this after some genetic work was done by the authors of Mercure et al. (1993) claiming that of the multiple subspecies of the kit fox in the western United States, the San Joaquin Valley population was the most distinct, earning them the title of becoming their own distinct subspecies of kit foxes. These tiny and secretive animals are about the size of a house cat, with an average body length of of 30.98 inches and a tail of 11.4 inches in length. They have long slender legs and are about a foot high at the shoulder weighing roughly 5 lbs. They have relatively large ears that are close together, a narrow nose, and a long, bushy tail with a black tip as shown above. They're tan colored during the warmer months of the year and their coat changes to a silver-gray during the winter months, all while maintaining a relatively white and yellowish underside year round. Their foot pads are small in comparison to other kit foxes with an average length of 1.2 inches and an average width of 1 inch. Their longer ears are the best way to tell them apart from their close, neighboring relatives in that their ears are three quarters of an inch longer than the gray foxes.

San Joaquin Kit Foxes feast on the typical prey of a carnivore their size in the wild on grasslands: rodents and other small animals in their geographic range such as black-tailed hares, desert cottontails, mice, kangaroo rats, squirrels, birds and lizards. They themselves are preyed on by carnivores larger than them, mainly red foxes because of their size difference ad also coyotes. The best time to try and spot one is near sunset or even at night because they are primarily nocturnal. Some may venture out of their dens with their young but this typically will only happen as the sun is setting and they definitely will not be venturing too far away from their dens. Their mating season begins in December and ends in March in which they produce litters of between 2 and 6 pups. The parents and litter live in underground dens which are necessary to keep them cool in the summer and warm in the winter. These dens also keep them safe from coyotes, red foxes, and shelter their pups as they mature. San Joaquin Kit Foxes use dens built by other animals or structures such as large drainage pipes they find in fields or even near cities. Just one fox may use between three and 24 different dens each year. The parent San Joaquin Kit Foxes care for their pups until the pups are able to find food for themselves and venture away from their den which typically happens between 4-5 months of age. Studies have also shown that some juvenile female pups or male pups may stick with their parents for almost a year, helping to clean the den and sometimes help foster a new litter. This is not a typical occurrence but it can happen!

Geographic and Population Changes

As talked about above, San Joaquin Kit Foxes were found throughout most of the San Joaquin Valley in California but this was, in a way, speaking with a past tense. Debates about the exact historical range population have been going on for years but the authors of Grinnell et al. (1937) believed that by 1930, the San Joaquin Kit Fox range had been reduced by more than half. This is because this was around the time that people began to convert the home grasslands of the kit foxes into farms, orchards, and cities. Today, there are fewer than 7,000 San Joaquin Kit Foxes remaining in the once heavily populated San Joaquin Valley. It's scary to think about the impact humans have had on the homeland of the foxes in such a short amount of time due to agriculture, population growth, and urbanization.

Listing Date, Cause of Listing, and Main Threats 

The San Joaquin Kit Fox was listed as endangered by the U.S. Department of the Interior in 1967 and by the state of California in 1971. It still remains endangered today both federally and in California. The loss and degradation of habitat by agricultural and industrial developments has and continues to drop the carrying capacity of the San Joaquin Kit Fox's habitat. Urbanization and cattle grazing has also played a role. Reduced rainfall and increase changes of drought due to climate change are a factor as well in San Joaquin Kit Fox populations. The more rain, the more kit foxes so when there's no a lot of rain, you're not going to see the same amount of kit foxes. Red foxes and coyotes assist in decreasing the population of San Joaquin Kit Foxes being that they are the target prey a majority of the time  but that's far less of a toll than what human interaction and climate change does to the San Joaquin Kit Foxes. Another threat humans put on the foxes population size is using poisons to reduce rat and mice populations. Not only are the poisons deadly to the foxes if eaten but they can be easily transmitted through the fox's prey that had previously taken in the poison.

Recovery Plan

According to the Recovery Plan for Upland Species of the San Joaquin Valley, California put out by the U.S. Fish and Wildlife Service,the goal of the recovery plan is to work towards the establishment of a viable complex of San Joaquin Kit Fox populations on private and public lands throughout their geographic range in California. Conserving a number of populations, some much more significant than others because of their large sizes or strategic locations, will be a necessary foundation for recovery of the San Joaquin Kit Fox. The areas these populations inhabit need to include as much of the environmental variability of the past, historical range as possible. This will ensure that maximum genetic diversity will be conserved in the kit fox metapopulation to respond to varying environmental conditions. Also, connections need to be established, maintained, and promoted between the populations to stop the negative consequences of inbreeding between the foxes, random catastrophic events like the drought California is still going through right now, and demographic factors. The three core populations that need to first be established back to what they were in the past due to their decreasing size are the Carrizo Plain natural area in San Luis Obispo County, the natural lands of western Kern County inhabited by the San Joaquin Kit Fox, and the Ciervo-Panoche natural area of western Fresno and eastern San Benito Counties. These three populations are more or less connected by grazing lands although they are steep and dense in some areas. This is a key factor because this provides linkages to the three core populations once they themselves start expanding. It  may take some time but once these populations begin to grow, we will be seeing the populations of the San Joaquin Kit Fox increase at a much quicker pace which will lead to the spread of the foxes over their previous natural habitats in the San Joaquin Valley. This result will be better than the decrease of the kit foxes we are currently seeing year after year. 

Personal Action?

After reading this blog about the endangered San Joaquin Kit Fox, you may be asking yourself how you can help to save them? For one, you could go to this link http://www.defenders.org/san-joaquin-kit-fox/basic-facts and donate money to the good folks of Defenders of Wildlife who have already begun to help the San Joaquin Kit Fox by partnering up with the California Cattlemen's association to form the California Rangeland Conservation Coalition. They already have more than 50 members working to save 13 million acres of rangeland in the Central Valley through easements and restoration projects in which more than a million acres of that falls within essential San Joaquin Kit Fox habitat. You could also follow the link to http://ecos.fws.gov/ipac/ from the U.S. Fish and Wildlife's website to assist you in determining how your activities may impact sensitive natural resources for the San Joaquin Kit Fox and obtain suggestions for ways you can address these impacts yourself. These may seem like two small contributions but giving a little is giving a lot when it comes to the recovery of the once abundant population of the San Joaquin Kit Fox.  

References:

http://ecos.fws.gov/docs/recovery_plan/980930a.pdf

http://ecos.fws.gov/ipac/

http://www.fws.gov/sacramento/es/Recovery-Planning/Home/es_recovery.htm

http://www.defenders.org/san-joaquin-kit-fox/basic-facts

http://esrp.csustan.edu/speciesprofiles/profile.php?sp=vuma

http://www.asktheexterminator.com/wild_animals/Fox_Facts_printer.shtml

http://ecos.fws.gov/tess_public/profile/speciesProfile?spcode=A006#conservationPlans