Camas pocket gopher

Camas pocket gopher
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	Geomyidae
Genus:	Thomomys
Subgenus:	Megascapheus
Species:	T. bulbivorus
Binomial name
Thomomys bulbivorus (Richardson, 1829)
Distribution of the camas pocket gopher in the Willamette Valley of northwest Oregon
Synonyms[2]
List Diplostoma bulbivorum Richardson, 1829 Diplostoma douglasii Richardson, 1829 Geomys bulbivorus Richardson, 1837 Ascomys bulbivorus Wagner, 1843 Pseudostoma bulbivorum Audubon & Bachmann, 1854 Geomys (Thomomys) bulbivorus Giebel, 1855 Thomomys bulbivora Brandt, 1855 Thomomys bulbivorus Baird, 1858 Thomomys (subgenus Megascapheus) bulbivorus Elliot, 1903

The camas pocket gopher (Thomomys bulbivorus), also known as the camas rat or Willamette Valley gopher, is a rodent, the largest member in the genus Thomomys, of the family Geomyidae. First described in 1829, it is endemic to the Willamette Valley of northwestern Oregon in the United States. The herbivorous gopher forages for vegetable and plant matter, which it collects in large, fur-lined, external cheek pouches. Surplus food is hoarded in an extensive system of tunnels. The dull-brown-to-lead-gray coat changes color and texture over the year. The mammal's characteristically large, protuberant incisors are well adapted for use in tunnel construction, particularly in the hard clay soils of the Willamette Valley. The gophers make chattering sounds with their teeth; males and females make purring (or crooning) sounds when they are together, and the young make twittering sounds. Born toothless, blind and hairless, the young grow rapidly before being weaned at about six weeks of age.

Although the camas pocket gopher is fiercely defensive when cornered, it may become tame in captivity. While population trends are generally stable, threats to the species' survival include urbanization, habitat conversion for agricultural use and active attempts at eradication with trapping and poisons. It is prey for raptors and carnivorous mammals, and host to several parasitic arthropods and worms. Scientists believe that the gopher's evolutionary history was disrupted when the Missoula Floods washed over the Willamette Valley at the end of the last ice age. The floods almost completely inundated its geographic range, which may have caused a genetic bottleneck as survivors repopulated the region after the waters receded.^{[citation needed]}