The Idaho pocket gopher (''Thomomys idahoensis'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

in the family Geomyidae. It is rather small, with a lightly built skull. Its fur color varies through the body and between individuals. Found in the western

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

, it inhabits

savannas A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

shrubland Shrubland, scrubland, scrub, brush, or bush is a plant community characterized by vegetation dominated by shrubs, often also including grasses, herbs, and geophytes. Shrubland may either occur naturally or be the result of human activity. It m ...

, and

grasslands A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natural ...

. Individuals live alone in burrows, staying active year-round. Many aspects of its behavior and biology are not well understood. The species is classified as being of

least-concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

by the

International Union for the Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

Taxonomy

''Thomomys idahoensis'' was first described by

Clinton Hart Merriam Clinton Hart Merriam (December 5, 1855 – March 19, 1942) was an American zoologist, mammalogist, ornithologist, entomologist, ecologist, ethnographer, geographer, naturalist and physician. He was commonly known as the 'father of mammalogy', a ...

in 1901. The type locality was given as Birch Creek,

Idaho Idaho ( ) is a state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Montana and Wyom ...

, and the type specimen was a male collected in 1890. It has no recent synonyms, although its two of its subspecies (''T. i. idahoensis'' and ''T. i. pygmaeus'') were once considered

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

of '' Thomomys talpoides'', the northern pocket gopher. It belongs to the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

'' Thomomys'', which is distributed throughout western

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

. This genus is part of the family Geomyidae.

Subspecies

Three

are recognized: *''T. i. idahoensis'' — high variance in size and coloration in different populations within the subspecies, found in eastern

and nearby parts of

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

. The largest are found in the

Snake River Plain image:Snake River view near Twin Falls, Idaho.jpg, The Snake River cutting through the plain leaves many canyons and Canyon#List of gorges, gorges, such as this one near Twin Falls, Idaho The Snake River Plain is a geology, geologic feature ...

. *''T. i. pygmaeus'' — small and dark brown, found in southwestern

Wyoming Wyoming () is a U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the south ...

, southwestern Idaho, and northern

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

. It is the only subspecies found in Utah. *''T. i. confinus'' — found in western Montana.

Description

The size, weight, and hindfoot length of the Idaho pocket gopher are variable, although typically no more than , , and for each, respectively. The color of the back ranges from yellowish brown with dark brown tipped hair to grayish brown or fully dark brown, fairly uniform overall. Most are dark gray around the nose. The ventral area is light gray and usually mixed with yellow and yellow-brown. The feet are whitish in appearance, with tail color varying between specimens. It is paler in winter than summer. The gopher's skull is small and lightly built, with incisors that are slender and not

procumbent This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnify ...

(inclined towards the lips). Its

baculum The baculum (also penis bone, penile bone, or ''os penis'', ''os genitale'' or ''os priapi'') is a bone found in the penis of many placental mammals. It is absent from the human penis, but present in the penises of some primates, such as the ...

(a bone present in the penis of many mammals) is rather long, from , and the bullae (bony structures in the back of the skull) are large. It has either 56 or 58

chromosomes A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

(the difference is due to

Robertsonian translocation Robertsonian translocation (ROB) is a chromosomal abnormality wherein a certain type of a chromosome becomes attached to another. It is the most common form of chromosomal translocation in humans, affecting 1 out of every 1,000 babies born. It doe ...

, a condition where a chromosome becomes attached to another). The ears are small.

Distribution and habitat

The Idaho pocket gopher is found in the western

, from central Idaho to the southern and western parts of Montana. A separate population exists in southwestern

, southeastern Idaho, and northeastern

. It resides in

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

, and

grassland A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur natur ...

habitats.

Behavior and ecology

Individuals live in burrows, with each gopher creating and living in its own burrow. They remain active for the entire year, and store excavated soil in their burrows, which stays after the snow has melted. It is

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

in certain areas with the northern pocket gopher, which it does not interbreed with. The former species prefers shallower, rockier soils, while the latter prefers deeper soil with fewer rocks. It is not known what the Idaho pocket gopher eats, although related species consume parts of plants from vegetation below and above ground level, mainly

forbs A forb or phorb is an herbaceous flowering plant that is not a graminoid (grass, sedge, or rush). The term is used in biology and in vegetation ecology, especially in relation to grasslands and understory. Typically these are dicots without woo ...

and

grasses Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns and ...

Reproduction and life cycle

Little is known about the life history of this species, with no known data on breeding season and litter size. It most likely breeds in spring after the snow has melted. It is likely similar to the northern pocket gopher with regards to breeding behavior: the latter species gestates for 19 to 20 days and bears between four and seven offspring. Its lifespan is also unknown, although pocket gophers usually live for less than two years.

Conservation

There is no known existence of this species in protective areas or captivity. It is protected by the US state of Montana. The

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

has evaluated it as being of

, as no major threats are present, it has a large range, and its population is not declining fast enough to warrant a more threatened listing (although the population trend is unknown). It is listed in the Utah Wildlife Action Plan as a species greatly needing conservation.

Sources

{{Taxonbar, from=Q45592

Idaho pocket gopher The Idaho pocket gopher (''Thomomys idahoensis'') is a species of rodent in the family Geomyidae. It is rather small, with a lightly built skull. Its fur color varies through the body and between individuals. Found in the western United States, ...

Mammals of the United States

Rodents of North America Mammals described in 1901 Least concern biota of the United States Taxonomy articles created by Polbot