Merriam's Ground Squirrel
Encyclopedia
Merriam's ground squirrel (Urocitellus canus) is a species of rodent
in the family Sciuridae. It occurs in the states of Idaho
, Nevada
, and Oregon
in the United States
.
with a relatively nondescript appearance. Adults range from 18.8 to 21.8 cm (7.4 to 8.6 ) in head-body length, with a 3.1 to 5 cm (1.2 to 2 ) tail. Although their weight varies throughout the year, depending on nutrition, typical adult weights of 144 to 210 g (5.1 to 7.4 ) have been recorded for females, and 146 to 300 g (5.1 to 10.6 ) for males.
The fur is short and lacks any distinctive markings such as stripes or spots. It is greyish buff over most of the body, and pale buff to white on the underparts. The tail is relatively short and narrow compared with most other related ground squirrels, and the ears are small. However, it can only be reliably distinguished from Townsend's ground squirrel
and the Piute ground squirrel
by genetic testing, and, for a long time, these species were not considered to be separate.
, although not in the northern and western regions of the state. Some populations extend south of the state line into the extreme north-eastern corner of California
and the extreme north-western corner of Nevada
, while other populations extend along the west bank of the Snake River
into western Idaho
.
Two subspecies are generally recognised:
The native habitat of Merriam's ground squirrel is arid chapparal environments dominated by sagebrush
, and, to a lesser extent, by greasewood
and shadscale
. It is sometimes found in marginal juniper
woodland and can be common in man-made pasture and fields.
s. Althogh relatively little of its native habitat has been converted into farmland, where it does inhabit agricultural land, it may eat domesticated grains or alfalfa
, and be considered as a pest. Known predators include barn owl
s and great horned owl
s, and presumably also include hawks, snakes, and various carnivorous mammals.
They construct burrows, and rarely wander far from their entrances, typically having a home range of less than 1 hectares (2.5 acre). They spend most of the year hibernating
; although there is some variation with local habitat, they generally emerge in early March, and become dormant again in early August. They give birth to a single litter of up to ten young each year in late April or early May. The gestation period and duration of weaning are unknown, but are probably each in the range of three to four weeks.
They are quiet and secretive animals, with a shrill, squeaking, alarm call, and have been observed to climb low bushes in search of food and to be good swimmers.
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
in the family Sciuridae. It occurs in the states of Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
, Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, and Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Description
Merriam's ground squirrel is a small, grey, ground squirrelGround squirrel
The ground squirrels are members of the squirrel family of rodents which generally live on or in the ground, rather than trees. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known as marmots or prairie dogs, while the smaller and less...
with a relatively nondescript appearance. Adults range from 18.8 to 21.8 cm (7.4 to 8.6 ) in head-body length, with a 3.1 to 5 cm (1.2 to 2 ) tail. Although their weight varies throughout the year, depending on nutrition, typical adult weights of 144 to 210 g (5.1 to 7.4 ) have been recorded for females, and 146 to 300 g (5.1 to 10.6 ) for males.
The fur is short and lacks any distinctive markings such as stripes or spots. It is greyish buff over most of the body, and pale buff to white on the underparts. The tail is relatively short and narrow compared with most other related ground squirrels, and the ears are small. However, it can only be reliably distinguished from Townsend's ground squirrel
Townsend's Ground Squirrel
The Townsend's ground squirrel is a species of rodent in the Sciuridae family. It is found in high desert shrublands in several areas of the United States.-Distribution:...
and the Piute ground squirrel
Piute Ground Squirrel
The Piute ground squirrel is a species of rodent in the family Sciuridae. It is endemic to the United States....
by genetic testing, and, for a long time, these species were not considered to be separate.
Distribution and habitat
The species is found throughout much of OregonOregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
, although not in the northern and western regions of the state. Some populations extend south of the state line into the extreme north-eastern corner of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and the extreme north-western corner of Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, while other populations extend along the west bank of the Snake River
Snake River
The Snake is a major river of the greater Pacific Northwest in the United States. At long, it is the largest tributary of the Columbia River, the largest North American river that empties into the Pacific Ocean...
into western Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
.
Two subspecies are generally recognised:
- Urocitellus canus canus - Oregon, California, Nevada
- Urocitellus canus vigilis - Snake River region (eastern Oregon, western Idaho)
The native habitat of Merriam's ground squirrel is arid chapparal environments dominated by sagebrush
Artemisia tridentata
Artemisia tridentata is a shrub or small tree from the family Asteraceae. Some botanists treat it in the segregate genus Seriphidium, as S. tridentatum W. A. Weber, but this is not widely followed...
, and, to a lesser extent, by greasewood
Greasewood
Greasewood, Sarcobatus, is a genus of one or two species of flowering plants. Traditionally it has been treated in the family Chenopodiaceae, but the APG II system, of 2003, places it in the family Sarcobataceae....
and shadscale
Atriplex confertifolia
Atriplex confertifolia is a species of evergreen shrub in the Chenopodiaceae family, which is native to the western United States.-Habitat:Shadscale is a common, often dominant, shrub in the lowest and driest areas of the Great Basin...
. It is sometimes found in marginal juniper
Juniper
Junipers are coniferous plants in the genus Juniperus of the cypress family Cupressaceae. Depending on taxonomic viewpoint, there are between 50-67 species of juniper, widely distributed throughout the northern hemisphere, from the Arctic, south to tropical Africa in the Old World, and to the...
woodland and can be common in man-made pasture and fields.
Behavior
Merriam's ground squirrel is a diurnal omnivore, feeding on a wide range of seeds, roots, and bulbs, as well as on insects, such as cicadaCicada
A cicada is an insect of the order Hemiptera, suborder Auchenorrhyncha , in the superfamily Cicadoidea, with large eyes wide apart on the head and usually transparent, well-veined wings. There are about 2,500 species of cicada around the world, and many of them remain unclassified...
s. Althogh relatively little of its native habitat has been converted into farmland, where it does inhabit agricultural land, it may eat domesticated grains or alfalfa
Alfalfa
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...
, and be considered as a pest. Known predators include barn owl
Barn Owl
The Barn Owl is the most widely distributed species of owl, and one of the most widespread of all birds. It is also referred to as Common Barn Owl, to distinguish it from other species in the barn-owl family Tytonidae. These form one of two main lineages of living owls, the other being the typical...
s and great horned owl
Great Horned Owl
The Great Horned Owl, , also known as the Tiger Owl, is a large owl native to the Americas. It is an adaptable bird with a vast range and is the most widely distributed true owl in the Americas.-Description:...
s, and presumably also include hawks, snakes, and various carnivorous mammals.
They construct burrows, and rarely wander far from their entrances, typically having a home range of less than 1 hectares (2.5 acre). They spend most of the year hibernating
Hibernation
Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...
; although there is some variation with local habitat, they generally emerge in early March, and become dormant again in early August. They give birth to a single litter of up to ten young each year in late April or early May. The gestation period and duration of weaning are unknown, but are probably each in the range of three to four weeks.
They are quiet and secretive animals, with a shrill, squeaking, alarm call, and have been observed to climb low bushes in search of food and to be good swimmers.