Thirteen-Lined Ground Squirrel

## Description

This small and slender ground squirrel, also known as the "thirteen liner" has 13 stripes running along the length of its body. The dark brown stripes are wider than the tan ones and have rectangular tan spots along the middle, and are either seven wider dark brown stripes alternating with tan or seven narrow tan stripes alternating with six dark brown ones. They have short ears and their tail is thin and a little bushy. They often sit erect with their head pointing up. As many as 90% of babies are taken by predators before the start of hibernation. Once reaching adulthood it is probable that they live for just a few years. Squirrels in captivity may live as long as 7.9 years

## Distribution

The Thirteen-lined ground squirrel lives throughout the central United States and Canada, from southern Alberta, Manitoba and Saskatchewan to east central Arizona, central Ohio and the Texas Gulf Coast and also straddling the Arizona-New Mexico border. These animals prefer open areas that have short grass and well-drained loamy or sandy soils for burrows. They are not found in wooded areas. They are also often found on mowed lawns, golf courses, well-grazed pastures, cemeteries, parks and roadsides.

## Behavior

Thirteen-lined ground squirrels are a diurnal species and are most active during midday and warm sunny days. These animals dig shallow blind-end burrows for use in emergencies, as well as deeper complex underground burrows for nesting and hibernation. They are not colonial but they may focus one area which has desirable substrate. These squirrels are territorial and defend their home burrows. In autumn they quickly gain weight in preparation for winter dormancy, which is from August to March. Food caches are eaten when they wake from hibernation, especially just before emerging. Thirteen liners have very good senses of vision, smell and touch. They communicate with other squirrels by the use of alarm calls and other noises, and also use special scented secretions.

## Diet

Thirteen liners are omnivores, mainly eating seeds, grass and leaves. They also eat insects, lizards, small birds and carrion.

## Reproduction

Thirteen liners are polygynous, which means that one male mates with multiple females. 75% of each litter is fathered by the first male to mate with the mother. Males come out of hibernation before females in order to seek breeding partners. Mating begins 2 weeks after hibernation, usually in mid-April. After gestation of 28 days, a litter of 3 to 14 (average 10) naked, blind, and toothless pups is produced. 1 litter only is produced each year. The young weigh around 1/10 ounce (3 to 4 g) when born. Their stripes start to appear when they are about 12 days old and their eyes open at 28 to 30 days. They are weaned and independent at 6 to 12 weeks. These squirrels become sexually mature at 9 to 10 months old.

## Population

### Threats

There are no significant threats to the Thirteen-lined ground squirrel at present.

### Number

According to IUCN, Thirteen-lined ground squirrel is common and widespread throughout its range but no overall population estimate is available. Currently this species is classified as Least Concern (LC) and its numbers remain stable.

### Ecological niche

This species impacts plant communities by eating their seeds and foliage, and they help to recycle nutrients in the soil when they burrow. They are an important source of prey for small predators like weasels, raptors, hawks and snakes.

## Fun Facts

Thirteen-lined ground squirrels are true hibernators, which allow their body temperature to decrease to just above freezing point, while their heart rate drops to 20 beats a minute from its usual 200.

The scientific name of these squirrels, “Spermophilus” means "seed lover”.

Thirteen-liners rub scent from glands around their mouths onto objects to leave their marks.

Thirteen-lined ground squirrels touch noses or lips in greeting, so it looks as if they kiss each other.

This squirrel is the mascot for the “Golden Gophers” of the University of Minnesota.

A children’s book called “Earnest, the Moose Who Doesn’t Fit” by Catherine Rayner features a thirteen-lined ground squirrel.

Squirrels can fall from a height of 30 m without hurting themselves.

“Squirrel” in Greek means “shadow tail”.

Squirrels are clever enough to navigate many obstacles to work out the most efficient route in order to get food, including finding shortcuts.