The San Joaquin Valley of California is a region of immense biological diversity, and includes a number of endemic species and unique biotic communities. California harbors more unique plants and animals than any other state, and its biotic communities also face intense pressures. With the human population of California increasing every year, there is always more and more demand on the remaining habitat. Undeveloped habitat the size of San Francisco is converted to residential or commercial use every six months. The State of California lists 34 species of animals and 46 species of plants as having been extirpated since the 1880s. The combined state and federal lists of rare, threatened, or endangered plant and animal species in the state totals 330, and there are more candidate species identified. One of these listed species is the endangered San Joaquin kit fox.
The San Joaquin kit fox is the largest of the 8 subspecies of kit foxes. An adult kit fox stands 22-30cm (9-12 in.) at the shoulder and averages about 51 cm (20 in.) in body length. Its tail adds another 30 cm (12 in.). Fully grown, the kit fox weighs about 2.3 kg. (5 lbs.)