Chipmunk

Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Rodentia
Family Sciuridae
Tribe Marmotini
Genus Tamias

Genus Tamias refers to the 24-odd species of small, squirrel-like animals known as chipmunk.

Originally, the name may have been spelled chitmunk, from the Ojibwe ajidamoo — red squirrel. To Westerners, the term originated in 1842 when the Oxford English Dictionary honored them with an entry under chipmonk. Suffixing their name with monk makes sense — they sit upright, clasping their hands in front of their faces as though in prayer. Of course, clasped in the tiny hands is usually something like a seed, or part of a slug; something a kid might do in church when the sun is out. But these are mischievous critters.

Chipmunks are absent-minded. This is why we have forests in North America.

Like many mammals, chipmunks are diurnal. They sleep during the winter. And like squirrels, they steel themselves for the cold by burying seeds and nuts everywhere the ground is soft enough to dig. We call it scatter hoarding. But as time passes, and the number of hiding spots grows, a fair number are lost to memory. The stashes germinate, and become trees. The trees produce seeds and nuts. The chipmunks gather them, bury them, and forget. The result: forest.

Chipmunks are an almost exclusively North-American phenomenon. One species, sibericus, lives in China. In their North American range, they flourish everywhere except the great plains and the hot forests of Florida; no chipmunk ventures north of the Canada treeline. In the mountains they're known to venture above the timber line, and some scurry in the dust of the southwestern semi-desert.

As taxonomers are wont to do, they have divided genus Tamias into two sub-genera: one also named Tamias and one named Neotamias. Tamias — classification of the Chinese chipmunk — populates Eastern Canada and the Eastern US, up to the dreaded treeline. The bulk of the genus is comprised of Neotamids, who make home in western North America, extending south into Mexico along the mountains. Twenty of the twenty-four chipmunk species are Neotamids.

Tamias, Neotamias. This means little unless you're a biologist, or interested in taxonomy. The armchair biologist uses her eyes.

The archetypal chipmunk — the reddish-brown critter with bold stripes up the back — is the eastern chipmunk. The one in Bambi, that was an easterner. White belly, little brown feet. Some ground squirrels are confused for eastern chipmunks because of their stripes; the stripes of chipmunks go all the way up to the head, while those of squirrels do not. As rodents go, eastern chipmunks have stout tails — around a third of total body length.

Looks-wise, westerners got the short end of the stick. They sport shades of grey and ash-brown; some wear messy spots. Everything here looks like granite. They're also smaller, weighing in at around 55g to the Easterner's 125g. Their tails are longer and thinner, some half total body length. The little westerners come in anywhere between 16 and 28cm, while the more charismatic and attractive easterners are between 20cm and 30cm.

When you think you're listening to songbirds in the forest, you're probably hearing chipmunks.

Most rodents are silent, unless they're pissed. Not chipmunks. They have a language of, biologists think, 30 combinations of chirps and chips. When startled, they run and sound off, short and quick, like a smoke detector with a low battery. When in a position to heckle you from a distance, they chirp high and loud, allowing a second or two of sinking-in time between each vocalization. Incidentally, this scolding and the mating call of the female may be one and the same.

As for body language — everything which moves has body language — Toni Will-Harris summed up chipmunk angst, brilliantly:¹

They [baby chipmunks] were clinging to her [mother chipmunk's] back and she had obviously had about enough of them. While they were able to walk by themselves, they were used to her feeding them and taking care of them, and they liked it. She put up with it for a few minutes, and then she shook them off and started eating. They tried to climb back on her, but she turned her head and lightly scolded them, with little irritated noises. They paused for a moment and then more vigorously tried to get on her back. Now she had really had it with them. She wheeled around and faced them, practically shrieking. She ranted at them for about twenty seconds, and then she lunged at them, as if she was going to bite them. She seemed to be telling them to get a life and get off her back, permanently.

They started licking their hands and washing their faces, which is what a distressed or upset chipmunk does.

I have seen this behavior over and over. In times of stress, when you don't know what to do, clean your face.

Chipmunks are accomplished home-builders. While a few species nest in holes in trees, or in the canopies themselves, most chipmunks dig their homes out of the ground. Their burrows may have several entrances, each concealed with rocks or brush. Because a chipmunk will dig its entire life — some four or five years — there have been burrows found over thirty feet long.

These animals are sticklers for organization. The burrow entrance will be spoiled by no mound of dirt nearby, and its interior will have a sleeping chamber at the back, and, sometimes, small wings extending from the sides of the shaft for the storage of food and bodily waste. The sleeping area is insulated with grass, seeds with fluff, anything which can trap warm air.

As likeable as they are, chipmunks are solitary animals. An individual will claim a range up to a hectare in size. But they're not territorial in the traditional sense. Frequently, ranges will overlap, sometimes completely; chipmunks will even walk all over strangers' burrows without inciting a brawl.

Like any rodent worth its salt, a chipmunk can stuff its face to double the size of its head. To compete, yours truly would have to fit eight oranges into each cheek. Rodents are seed-eaters. While chipmunks subsist primarily on things like acorns and fruit, they're omnivorous. They'll take down beetles and eat slugs and worms. They're even known to crack bird eggs open. As consummate friends of the forest, they eat fungi harmful to trees. To a gardener, a family of chipmunks is a mixed bag — it will steal fruit, but eat harmful parasites.

Chipmunks prepare food for storage by breaking it up. Seeds are removed from pods, nuts are shelled. Using the tongue, food is maneuvered into the elastic cheeks; when its face is full to bursting, the chipmunk drops its load in the burrow. Much of a chipmunk's day is spent foraging.

Even in the southwestern US, chipmunks are hibernators. At the end of summer, they step up food collection, storing huge amounts for the winter. When the cold comes in November they disappear underground, waking once every two weeks to eat. In March they return to planet Earth, sometimes digging up through a meter of snow.

Chipmunks are born naked and blind shortly after winter. They weigh two grams — about half the weight of a nickel. Their ears are fused shut. Things don't get better for awhile.

After four weeks, the ears open; after five weeks, the eyes open. After ten days, hair sprouts. After six weeks, they feel sunlight.

Growth is rapid through late summer; a chipmunk is usually adult size by its first fall. The first mate comes with the first spring.

When the snow melts, the males are the first ones out of their burrows. Two weeks later, females emerge; following a winter of torpor and sexual frustration, chipmunks fight and copulate. Following a 30-day gestation period, the young chips are born; the litters, four to six strong, are reared by the female.

Because they are small rodents, chipmunks are eaten frequently.

While their enemies are typical rodent fare — birds of prey, housecats — they also fall victim to snakes, which enter their burrows. Others on the enemies list include foxes, weasels, and martens. Chipmunk is on a lot of menus. Typically, chipmunk populations hold steady. But there have been declines and disappearences which are not satisfactorily explained. If you're a chipmunk, there are a lot of ways to die without being eaten.

Like many small animals, chipmunks do not understand the gravity of a strip of asphalt.

When they compete for mates, chipmunks fight. Sometimes viciously so. They've got incisors, yes, and can inflict fatal wounds. They also get into scrapes with larger animals, like squirrels, over food.

We like chipmunks, but we know surprisingly little about them. We're not sure about their relationship with parasites. But if data on mice and other small rodents is to be believed, tapeworm, bot fly larvae, mites, fleas, and lice are a large enough problem to thin the ranks considerably.

So, you want to banish chipmunks from your property.

Rodents are slippery animals. Check for gaps under your doors; fit them with rubber sweeps. Fill open piping with steel wool. Leave things that reek of human — hair, old clothes — in places where chipmunks pass.

Rodents are also acrobats. Make sure you don't have any tree branches hanging over your roof. you'd be surprised how many animals know the significance of a chimney.

Keep food and trash secure in metal or plastic containers. One man's trash etc.

You've got to secure fences. Chipmunks dig, remember? At the base of the fence, dig a trench six inches to a foot deep and run lengths of chicken wire through, attaching them at the top to the bottom of the fence. Bury the wire, and you've got an underground barrier.

If all else fails, get a cat.

So, you want to attract more chipmunks to your property.

First, feed them intelligently. Corn and small pieces of fruit work nicely. Peanuts are questionable, since their shells grow mold and the peanuts themselves expand in the stomach. Same goes for rice and, obviously, popcorn. Don't waste their little gut space feeding them things like potato chips. Chocolate and chewing gum are egregious no-nos.

That said, distribute chipmunk food away from bird feeders and, unless you want them running around in your house, away from your doors. Similarly, if you have hanging bird feeders, fit them with baffles so that your wild birds don't have to tangle with rodents for their food. If you don't want to pony up for a real baffle, use a pie plate.

Once you've got chipmunks hanging around your house, don't feed them from your hands. Most of the time, chipmunks are civil, sure. But they get excited, and confused, and rabies shots are expensive.

More?

• Alpine Chipmunk, Tamias alpinus
• Yellow pine Chipmunk, Tamias amoenus
• Gray-footed Chipmunk, Tamias canipes
• Gray-Collared Chipmunk, Tamias cinereicollis
• Great Chipmunk, Chipmunkus Greatus
• Cliff Chipmunk, Tamias dorsalis
• Merriam's Chipmunk, Tamias merriami
• Least Chipmunk, Tamias minimus
• California Chipmunk, Tamias obscurus
• Yellow-cheeked Chipmunk, Tamias ochrogenys
• Palmer's Chipmunk, Tamias palmeri
• Panamint Chipmunk, Tamias panamintinus
• Long-eared Chipmunk, Tamias quadrimaculatus
• Colorado Chipmunk, Tamias quadrivittatus
• Red-Tailed Chipmunk, Tamias ruficaudus
• Hopi Chipmunk, Tamias rufus
• Allen's Chipmunk, Tamias senex
• Siberian Chipmunk, Tamias sibiricus
• Siskiyou Chipmunk, Tamias siskiyou
• Sonoma Chipmunk, Tamias sonomae
• Lodgepole Chipmunk, Tamias speciosus
• Eastern Chipmunk, Tamias striatus
• Townsend's Chipmunk, Tamias townsendii
• Uinta Chipmunk, Tamias umbrinus

¹ "The Life Cycle of the Chipmunk." http://www.will-harris.com/chiplife.htm

The Chipmunk Place
http://www.chipmunkplace.org
http://www.chipmunkplace.org/facts.htm
http://www.chipmunkplace.org/control.htm
http://www.chipmunkplace.org/diet.htm
http://www.chipmunkplace.org/nests.htm

Wikipedia
http://en.wikipedia.org.wiki/Chipmunk

The Chip Monk
http://www.geocities.com/Area51/Hollow/4252/chipmonkbad.htm
http://www.geocities.com/Area51/Hollow/4252/chipmonkfood.htm

Hinterland Who's Who
http://www.hww.ca/hww2?id=86

Monterey Bay — Chipmunks of North America
http://www.montereybay.com/creagrus/chipmunks.html

Canadian Museum of Nature
http://www.nature.ca/notebooks/English/estchip.htm

Will-Harris House
http://www.will-harris.com/chiplife.htm

For the Quest

Chip"munk` (?), n. [Indian name.] Zool.

A squirrel-like animal of the genus Tamias, sometimes called the striped squirrel, chipping squirrel, ground squirrel, hackee. The common species of the United States is the Tamias striatus.

© Webster 1913.