Richardson’s ground squirrel
This story is featured in Montana Outdoors March-April 2017 issue
One of the best places in Montana to see wildlife is around a colony of ground squirrels. Colonies are clusters of burrows used by a dozen of more of the rodents, commonly called “gophers.” At a gopher colony, you stand a good chance of seeing burrowing owls, bull snakes, raptors, badgers, and sometimes a fox. And of course there are the ground squirrels themselves—sitting upright on their haunches looking for enemies, or scurrying back and forth between burrow openings and feeding areas.
The Richardson’s ground squirrel is one of six ground squirrel species in Montana. The others are the Uinta, Wyoming, Columbian, golden-mantled, and thirteen-lined. It’s tough to tell some of the species apart.
Generally, if you are east of the Continental Divide and north of I-90, odds are that it’s a Richardson’s.
Richardson’s ground squirrels are small, stout-bodied animals with short ears, large black eyes, and a relatively short, nonbushy tail. The fur is short, dense, and yellowish-beige—perfect camouflage in the dry prairies where these rodents live. The eye ring and sides of the head and neck are light buff, while the upper surface of the tail is black and edged with buff or tan. Adults are about a foot long, including the three-inch tail. Fully grown, they weigh about three-quarters of a pound.
Ground squirrels couldn’t survive long without their burrows. The rodents sleep, hibernate, raise their young, and escape predators and bad weather in these underground chambers and connecting passageways. Burrows are often clustered in loose colonies and dug in what appears to be impossibly hard soil. From their entrances, about 3.5 inches wide in a conspicuous mound of dirt, burrows extend three to six feet underground, and may run horizontally 50 feet or more.
Richardson’s ground squirrels spend most of the year—eight months or more—hibernating underground. Males are the first to emerge in spring, followed by females and their young. They return to hibernation in the same order, adult males first, as early as late June, then females, and then, in late summer and fall, juveniles. Gophers have several different calls, but the most frequently heard is a long whistle, which warns of a ground predator, or a short chirp when sighting a hawk or eagle.
The Richardson’s is the most northerly of the ground-dwelling squirrel species. They range over eastern and central Montana, the Dakotas, and the Canadian prairies.
Ninety percent of the species’ diet consists of the leaves, flowers, and seeds of grasses and forbs such as blue grama, milkvetch, and pigweed. They also eat introduced plants such as bromegrass, crested wheatgrass, clover, and, much to the annoyance of farmers and ranchers, seeds and seedlings of wheat, oats, and barley. Ground squirrels that live near croplands are typically bigger and produce larger litters than those residing on native prairie.
Richardson’s ground squirrels prefer heavily grazed, short-grass prairies. When prairies are plowed and planted with grain or alfalfa, these rodents quickly adapt, frequently establishing colonies around field edges.
Females mate within a few days of emerging from hibernation, in March or April, depending on temperature. Five to eight blind, hairless young are born following a roughly three-week gestation period. The young emerge from their burrows within a month, usually in late May or June. Females begin breeding at age one and produce a single litter each year. While young males disperse to new areas, mothers and daughters establish lifelong bonds and defend their home territories against males and unrelated females.
Many predators eat Richardson’s ground squirrels and help keep populations in check. Broad-winged hawks alone may take 15 percent of a population each season. Other predators include badgers, long-tailed weasels, bull snakes, coyotes, foxes, and domestic dogs and cats. Many ground squirrels are also killed on roads by vehicles. Despite such ever-present mortality, the species remains abundant throughout its range
Writer Dennis C. Joyes lives in Ontario and often returns to Montana, his home state.
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