Botta's pocket gopher

Species of mammal

Botta's pocket gopher (Thomomys bottae) is a pocket gopher native to western North America. It is also known in some areas as valley pocket gopher, particularly in California. Both the specific and common names of this species honor Paul Émile Botta, a naturalist and archaeologist who collected mammals in California in 1827 and 1828.

Botta's pocket gopher is a medium sized gopher, with adults reaching a length of , including a tail of The overall dental formula is Males are larger, with a weight of , compared with in the females. Male pocket gophers are widely believed to continue growing throughout their life. However, size variation would indicate that some males are predisposed to be larger than others, and the largest male may not be the oldest. Coloration is highly variable, and has been used to help distinguish some of the many subspecies; it may also change over the course of a year as the animals molt. Both albino and melanistic individuals have also been reported. However, Botta's gopher generally lacks the black stripe down the middle of the back found in the closely related southern pocket gopher, a feature that may be used to tell the two species apart where they live in the same area. Skeletal remains of Botta's pocket gophers, dating back 31,000 years, have been identified from Oklahoma. Around 195 subspecies have been described, mostly on the basis of geographical distribution. Some of these have previously been described as distinct species in their own right. The distribution of the type localities of these subspecies is as follows: The average adult Botta's pocket gopher has a body temperature of Burrowing can be extremely energetically demanding requiring between 360 and 3,400 times as much energy as moving across the surface, depending on soil density. Due to the high cost of burrowing, Botta's pocket gopher is good at conserving energy by having a low basal metabolic rate and thermal conductance. The main predators of this species include American badgers, coyotes, long tailed weasels, and snakes, but other predators include skunks, owls, bobcats, and hawks. This species is considered a pest in urban and agricultural areas due to its burrowing habit and its predilection for alfalfa; however, it is also considered beneficial as its burrows are a key source of aeration for soils in the region. Digging by Botta's pocket gophers is estimated to aerate the soil to a depth of about , The species also has been associated with the deaths of aspen in Arizona and creates patches of bare ground that may limit the establishment of new seedlings.

Botta's pocket gopher is highly adaptable, burrowing into a very diverse array of soils from loose sands to tightly packed clays, and from arid deserts to high altitude meadows. They are able to tolerate such a wide range of soils in part because they dig primarily with their teeth, which are larger and with a thicker layer of enamel than in claw digging gophers. In comparison, gophers digging with their claws are generally only able to dig in softer soils, because their claws wear down more quickly than teeth do in harder materials. Botta's pocket gophers are active for a total of about nine hours each day, spending most of their time feeding in their burrows, but are not restricted to either daylight or night time. They make little sound, although they do communicate by making clicking noises, soft hisses, and squeaks. but the gophers aggressively defend a larger exclusive area, of for males and for females, around the burrow entrance. Hybridization with Townsend's pocket gopher has also been reported, and it, too, appears not to extend much beyond the first generation.