The spotted ground squirrel (''Xerospermophilus spilosoma'') is a species of
ground squirrel
Ground squirrels are rodents of the squirrel family (Sciuridae) that generally live on the ground or in burrows, rather than in trees like the tree squirrels. The term is most often used for the medium-sized ground squirrels, as the larger ones ar ...
in the
rodent
Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...
family
Sciuridae
Squirrels are members of the family Sciuridae (), a family that includes small or medium-sized rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrel ...
. It is found throughout
Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
and the central and western
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
. Characterized by a white spotted back, the spotted ground squirrel is one of the smallest squirrels found in
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
. They are mainly
herbivorous
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...
, but also eat insects. A burrowing mammal, the spotted ground squirrel will make tunnels to store its food, as well as shelter and hibernation quarters.
Description

The spotted ground squirrel is one of the smallest squirrels to inhabit the northern hemisphere. It has many white linear dorsal spots, as well as a white underbelly. Coloration of the rest of its body varies greatly and can be different shades of brown, black, gray and white. Its skull resembles that of the
thirteen-lined ground squirrel, but is slightly broader in the interorbital and rostral regions. A unique characteristic of the skull is the presence of especially large auditory bullae. ''X. spilosoma'' has two
pelage
A fur is a soft, thick growth of hair that covers the skin of almost all mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an ...
s and
molt
In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is a process by which an animal casts off parts of its body to serve some beneficial purpose, either at ...
s each year. Adults emerging from hibernation usually display thicker pelages, which are shed by the springtime. Juveniles tend to have darker pelages than their adult counterparts. Fur color can be influenced by environmental surrounds, and it has been found that populations in soil rich areas tend to have darker colorings than grassland living populations.
[
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Distribution and habitat
The spotted ground squirrel can range from south central South Dakota
South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...
, through Nebraska
Nebraska ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Ka ...
where it inhabits sand hills present there. It's also found in eastern Colorado
Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...
, northwestern Oklahoma
Oklahoma ( ; Choctaw language, Choctaw: , ) is a landlocked U.S. state, state in the South Central United States, South Central region of the United States. It borders Texas to the south and west, Kansas to the north, Missouri to the northea ...
, western Texas
Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
, eastern Arizona
Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...
, western Kansas
Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...
, the large majority of New Mexico
New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...
and the southeastern part of Utah
Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...
. Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
species distribution is limited to south and central Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
. It is generally found within areas of deep sand soils where vegetation is sparse and scattered, aligning with the environments of the distributive areas it is found in. Being a burrowing animal, the spotted ground squirrel will inhabit sand hills and dunes where it makes it home and has even been found to dwell within abandoned prairie dog
Prairie dogs (genus ''Cynomys'') are herbivorous burrowing Marmotini, ground squirrels native to the grasslands of North America. There are five recognized species of prairie dog: black-tailed prairie dog, black-tailed, white-tailed prairie dog ...
burrows. Spotted ground squirrel burrows are usually found on short grass mesa's or along the banks of rivers. They prefer lighter, more sparse soil to create their burrows with and this is why they dwell in arid, dry landscapes that contain this type of soil.[
]
Diet
The spotted ground squirrel is a herbivore
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...
and feeds on seeds and green plant parts. It is generally not to be considered a carnivore
A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant
Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they ar ...
. Green grass shoots are consumed in the spring and eventually the flowers and seeds of green plants that arise in the summer. The spotted ground squirrel can also display Insectivore
file:Common brown robberfly with prey.jpg, A Asilidae, robber fly eating a hoverfly
An insectivore is a carnivore, carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the Entomophagy ...
like habits within its diet in the late summer by feeding on mainly Grasshopper
Grasshoppers are a group of insects belonging to the suborder Caelifera. They are amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago.
Grassh ...
larvae.[
]
Behavior
Though the spotted ground squirrel is considered to be generally a burrowing mammal which spends a large portion of its time in hibernation
Hibernation is a state of minimal activity and metabolic reduction entered by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It is mos ...
, it spends a majority of its above-ground activity foraging and feeding on food resources. With the rest of its time being dedicated to alert calls, maintenance behavior (resting, sun bathing, grooming) and sexual behavior in males and females. During their mating season sexual behavior plays a larger role in its above ground activity, involving a 'frenzy' like pattern of males entering and exiting their burrows sporadically, most likely observed as a type of courting behavior. The spotted ground squirrel have 7 different alert postures used to warn others about likely predators in the area or to stake a territory claim against other males during mating seasons. Hibernation
Hibernation is a state of minimal activity and metabolic reduction entered by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It is mos ...
behavior has been observed to begin in late July and go all the way through to April and May. Seasonal activity cycles occurs during the months of April/May through July/August and is estimated to be 115–135 days for males and 95–125 days for females.[
]
References
{{Taxonbar, from=Q1769954
Xerospermophilus
Mammals described in 1833
Taxa named by Edward Turner Bennett
Taxonomy articles created by Polbot