Richardson's ground squirrel (''Urocitellus richardsonii''), also known as the dakrat or flickertail, is a
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 ...
n
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 genus ''
Urocitellus
''Urocitellus'' is a genus of ground squirrels. They were previously believed to belong to the much larger genus ''Spermophilus'', but DNA sequencing of the cytochrome ''b'' gene showed that this group was paraphyletic to the prairie dogs and m ...
''. Like a number of other ground squirrels, they are sometimes called prairie dogs or gophers, though the latter name belongs more strictly to the
pocket gopher
Pocket gophers, commonly referred to simply as gophers, are burrowing rodents of the family Geomyidae. The roughly 41 speciesSearch results for "Geomyidae" on thASM Mammal Diversity Database are all endemic to North and Central America. They ar ...
s of family
Geomyidae, and the former to members of the genus ''
Cynomys''.
Taxonomy
This squirrel was named after the
Scottish
Scottish usually refers to something of, from, or related to Scotland, including:
*Scottish Gaelic, a Celtic Goidelic language of the Indo-European language family native to Scotland
*Scottish English
*Scottish national identity, the Scottish ide ...
naturalist Sir
John Richardson.
North Dakota
North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...
is nicknamed the
Flickertail state after the squirrel.
The nickname Dakrat is derived from "Dakota Rat" and is a commonly used name around Minot, North Dakota and on Minot Air Force Base.
Habitat
Native to the short grass
prairie
Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...
s, Richardson's ground squirrel is found mainly in the northern states of the
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 ...
, such as
North Dakota
North Dakota ( ) is a U.S. state in the Upper Midwest, named after the indigenous Dakota people, Dakota and Sioux peoples. It is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minneso ...
and
Montana
Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...
, and in western
Canada
Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...
, including central and southern
Alberta
Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...
, southern
Saskatchewan
Saskatchewan is a Provinces and territories of Canada, province in Western Canada. It is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and to the south by the ...
, and southern
Manitoba
Manitoba is a Provinces and territories of Canada, province of Canada at the Centre of Canada, longitudinal centre of the country. It is Canada's Population of Canada by province and territory, fifth-most populous province, with a population ...
.
[Animal Diversity Web]
/ref> The range of this animal expanded as forests were cleared to create farmland. They are not simply restricted to prairie; sometimes they adapt to suburban environments, causing them to be seen as pests because of the burrows they dig. It is not unusual to find squirrels digging tunnels under the sidewalks and patios of urban homes.
Description
Typical adults are about long. Weights vary greatly with time of year and with location: at emergence from 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 ...
the squirrels weigh between for females and between for males. But by the time they hibernate again, their weight may have risen to nearly . Males are slightly larger and heavier than females on average. They are dark brown on the upper side and tan underneath. The tail is shorter and less bushy than in other ground squirrels, and the external ears are so short as to look more like holes in the animal's head. Behavior is more like that of a 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 ...
than a typical ground squirrel. The tail is constantly trembling, so the animal is sometimes called the "flickertail".
Males have an average life expectancy of 3 years, while females average 4 years. However, in captivity some individuals may live for 5 to 7 years.
Behavior
Richardson's ground squirrels appear to live communally, but they organize their social structure around female kinship. A female Richardson's ground squirrel will tolerate the presence of closely related females, but are territorial towards other individuals. Individuals are territorial around their nest sites. The burrows of Richardson's ground squirrels are grouped closely together in colonies, and individuals give audible alarm call
"Alarm Call" is a song recorded by Icelandic singer Björk for her third studio album ''Homogenic'' (1997). It was released as the fourth single from the album, peaking at number 33 in the United Kingdom. The sped-up radio edit of the song was us ...
s when possible predators approach. Recent research has shown that in some cases, ultrasonic alarm calls are given, and are responded to by other members of the colony. Richardson's ground squirrels use two audible alarm calls, a high-pitched whistle and a 'chirp' call. The whistle is given in response to terrestrial predators, while the chirp is given in response to aerial predators such as hawks.
Predators include hawk
Hawks are birds of prey of the family Accipitridae. They are very widely distributed and are found on all continents, except Antarctica.
The subfamily Accipitrinae includes goshawks, sparrowhawks, sharp-shinned hawks, and others. This ...
s, owl
Owls are birds from the order Strigiformes (), which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers a ...
s, snake
Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...
s, weasel
Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets, and European mink. Members of this genus are small, active predators, with long and slend ...
s, American badgers and coyote
The coyote (''Canis latrans''), also known as the American jackal, prairie wolf, or brush wolf, is a species of canis, canine native to North America. It is smaller than its close relative, the Wolf, gray wolf, and slightly smaller than the c ...
s.
Feeding
These animals are omnivore
An omnivore () is an animal that regularly consumes significant quantities of both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize t ...
s, eating seeds, nuts, grains, grasses and insects (especially crickets, caterpillars and grasshoppers). They stuff their cheek pouches with seeds, which are stored in the burrow and likely eaten in spring. They are also reported to cannibalize ground squirrels killed by road traffic.
Hibernation
Adult ground squirrels may hibernate as early as July, though in their first year, the young ground squirrels do not hibernate until September. The males emerge from hibernation in March, and establish territories
A territory is an area of land, sea, or space, belonging or connected to a particular country, person, or animal.
In international politics, a territory is usually a geographic area which has not been granted the powers of self-government, ...
before the females emerge a couple of weeks later. Abandoned burrows are sometimes taken over by other grassland species such as the burrowing owl
The burrowing owl (''Athene cunicularia''), also called the shoco, is a small, long-legged, primarily terrestrial—though not flightless—species of owl native to the open landscapes of North and South America. They are typically found in gra ...
.
Reproduction
Female Richardson's ground squirrels produce one litter per year. Litter size averages 6, though the maximum size recorded is 14. The young are born in April or May. Young ground squirrels remain underground in the burrow
file:Chipmunk-burrow (exits).jpg, An eastern chipmunk at the entrance of its burrow
A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of Animal lo ...
until they are approximately 30 days old, emerging from natal burrows late May to mid-June. At emergence, the young weigh 50 to 100 grams.
Relationship with humans
Because they will readily eat crop species, Richardson's ground squirrels are sometimes considered to be agricultural pests, although this is not their legal status in all jurisdictions. The government of Saskatchewan
The Government of Saskatchewan () is the provincial government of the province of Saskatchewan. Its powers and structure are set out in the Constitution Act, 1867.
In modern Canadian use, the term "government" refers broadly to the cabinet of th ...
declared the animals pests in 2010, allowing local governments to employ gopher control measures. In areas with few natural predators, overpopulation and increasing density can drive ground squirrels to expand into suburban neighborhoods.
Control measures
Farmers and ranchers have developed a variety of ways to exterminate ground squirrels besides trapping, shooting and poisoning. One such process fills the burrows with a mixture of oxygen and propane and then ignites the gas mixture. This kills the ground squirrels with a concussive force that also collapses the tunnel systems. Even if effective, ground squirrels from outside of the treated areas will eventually spread back into the area.
The Saskatoon Wildlife Federation sponsored a 12-week "gopher derby" in 2002, in an effort to reduce what it considered an overpopulation of the squirrels. Cash prizes were awarded for the most number of animals killed, with the animals' tails being presented as proof of the kill. The Canadian Humane Society called the contest cruel and barbaric. Despite the criticism, the derby was repeated in 2003. By 2004, the ground squirrel population had dropped and the contest was cancelled.
The Gopher Hole Museum in Torrington, Alberta, Canada, has a large selection of stuffed ground squirrels of many varieties and colors.
Pet trade
The Richardson's ground squirrel in recent years has become popular in the exotic pet trade.
References
External links
Xander.it
- Spermophilus richardsonii (Richardson's ground squirrels) videos
American Society of Mammalogists species account (pdf)
*
Dr. Gail Michener's site on Richardson's ground squirrel
{{Authority control
Urocitellus
Rodents of Canada
Fauna of the Plains-Midwest (United States)
Rodents of the United States
Agricultural pests
Mammals described in 1858
Taxa named by Joseph Sabine