Chipmunk

Chipmunks that belong to the family of Sciuridae are both male and female chipmunks that are generally 25 species of small, striped rodents which are also known as terrestrial squirrels. They commonly possess large internal pouches attached to their cheeks for the transportation of food. Both male and female chipmunks have similar body structures with prominent eyes as well as ears, a flurry tail, and very delicate claws. All the various breeds of Chipmunk are very active during the day except one species that exists in south Canada and found till west-central Mexico and are popularly identified as North-American chipmunks. 

Chipmunks are generally known as pygmy squirrels that are adopted for exploiting understories of forests as well as rocky terrains. They generally run around on the ground but they are also expert climbers. All their species together as a group are classified as versatile geniuses. They can be seen on sea level to approximately 3900 meters (12800 feet) above sea level in an uphill environment classified as large rocks, cliffs, and boulders. They have their habitat in various forests like coniferous forests, deciduous forests to upwards into timberline slopes and alpine meadows that are rock bordered as well as in sagebrush deserts and scrublands. Here is a picture illustrating chipmunks.

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Ecology and Life History

Eastern chipmunks that include both the male chipmunk and female chipmunk mate twice a year, once in spring and once in early summer that results in the production of a maximum litter from which a maximum of four or five young ones are born twice every year. Unlike the former, western chipmunks mate only once a year. The young chipmunks are born from the borrows after almost six weeks of gestation and then within two weeks of emergence, the yongs start striking out on their own. Chipmunks are experts in creating burrows that can be as long as 3.5 meters or 11 feet in length with several entrances that are well concealed. These borrows are made in order to keep their sleeping quarters clean from the shells while feces are generally stored in refuse tunnels. These small mammals play a very important role in regulating the forest ecological system. The prime activity towards it is the harvesting as well as hoarding of the plants’ seed in order to establish the process of seeding. They also consume different varieties of fungi out of which few are involved in symbiotic mycorrhizal associations with several trees. They also play a very crucial role in transporting or dispersal of spores of subterranean truffles from its birth population to a different location where it can reproduce on its own which otherwise have lost its ability to disperse its spores on its own via air due to their co-evolution with these species as well as other mycophagous ( fungus eating) mammals. Unlike western chipmunks, eastern chipmunks hibernate during winters and totally rely on the stores they created in their burrows. Chipmunks are often the prey of other big mammals and birds in the food cycle but are themselves, opportunistic predators, as they feed on the birds’ eggs and nest, mostly seen in the case of eastern chipmunks as well mountain bluebirds that are biologically known as Siala Currucoides. Chipmunks in their natural habitat live up to three years but it has been observed that their life span increases up to 9 years when kept in captivity with special conditioning involved. Chipmunks show diurnal as they fall under the category of mammals that sleep on an average of 15 hours a day while hiding and in captivity. They sleep for longer hours when in hiding or captivity that provides them a sense of safety than the times when they need to be alert. The difference between a male chipmunk and a female chipmunk is cleared by observing the genital area situated above the anus. If a chipmunk possesses two bumps that are about a centimeter apart from each other then it's a sign of a male chipmunk but a female chipmunk just has a single bump in their genetal area.

Types of Chipmunks

Chipmunks usually have sharp shrill chirring or chipping voices. Most chipmunk species do not accumulate fat in their body and thus highly rely on the stored food in the borrows in winters. As per the observations made, chipmunks experience the lowering of body temperature and metabolism rate, thus they come out very seldomly during winters only if it is a sunny windless day. The body temperature of the chipmunk is usually between 34 to 41oC while they are in some kind of activity but drops down to 5 to 7oC while they are at rest. These characteristics show the true nature of hibernation. After a month's gestation period, about three to eight young are born in spring or summer. Their second litter is smaller than the first and is usually found in the regions with prolonged summers.  Thus, Chipmunks are categorized primarily on the basis of their length, weight as well as habitats. The categories are as follows:-

1. Eastern Chipmunks: the biological term that refers to eastern chipmunks are Tamias Striatus which commonly likes to habitat in dense forests thus are generally found in deciduous forests of eastern North America which is the largest of all deciduous forests. They also sometimes migrate to rural or suburban areas. They generally weigh 70 to 142 grams or 2.5 - 5 ounces and are 5-6 inches tall on average but few of them grow up to 11 inches long. They have shorter tails as compared to their other counterparts and the tail of this species generally measures 8 - 11 cm or 3.1 - 4.3 inches. They have brownish-red bodies with five dark stripes that are running downwards their body and are above the reddish-brown coat. They usually alternate with two white with two brownish-gray stripes down their backs. They have distinguishable two white stripes situated at the top and bottom of their eyes.

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2. Least Chipmunks: The biological name of these chipmunks is Tamias Minimus. This is the smallest of all the other varieties of chipmunks. They weigh about half the weight of the eastern chipmunks and that is approximately 1.1 to 1.8 ounces. They are generally 7.2 to 8.5 inches tall and are found throughout North America and precisely in the western states and also seen in western Canada. Some of them found their habitat in Michigan, Wisconsin as well as in Minnesota.  They are found generally in forests but sometimes they come out in open areas and also near water bodies. Their appearance is similar to that of the eastern chipmunks.

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3. Siberian or Asian Chipmunks: The Siberian chipmunks are commonly known as Asian chipmunks that are also the oldest species of chipmunks in the world, as their habitat is distributed across northern Asia that stretches from Russia to China, Koria, and in Hokkaido in northern Japan. In the 1960's they were transported from South Korea to Europe and introduced as pets. These are the only chipmunks that are found outside of North America. Though the chipmunks of these species may slightly vary in their appearances based on their habitat location, they possess characteristics that are similar to one another. They are about 18 - 25 cm or 7.1 to 9.8 inches tall and their tails measure about a third of their total height. The Siberian chipmunks usually weigh 50 to 150 grams or 1.8 to 5.3 ounces but the weight of adults may vary depending on the food availability and the time of the year. As compared to Sciuridae, these are generally smaller in size. Usually, this category of chipmunks does not show any sexual dimorphism, thus the only distinguishable characteristics for a younger and an older chipmunk is its size and proportions of the body.

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4. Other Varieties: among all the species only a group of chipmunks that are on the verge of extension and facing the threat of being completely wiped out of the earth’s surface is Palmer’s chipmunks that are generally found in the mountains of west Las Vegas and Nevada that are currently being monitored. The yellow pine chipmunks and the red-tailed chipmunk are the rarest but most noticeable chipmunks that are found only in the western states of America. As one moves to the extreme southwest corner in British Columbia, a rare species of chipmunks famously known as Townsend’s chipmunks are found. Other than these there are few other varieties of chipmunks that are known. One of the species that are commonly found at the canyonlands and buttes of Southwest America is the Hopi chipmunks whose biological name is T. Rufus and they are experts in climbing steep rock faces and overhanging. Another type of chipmunks is known as Uinta chipmunks that have a biological name as T. Umbrinus that are mostly found in the mountain forests situated in the west of the United States. Their general habitat is trees like normal squirrels. Other than their den in burrows, they mostly nest and sleep in trees. They are mostly seen bringing up their young in the hollow or the cavities of the tree or in some abandoned nest of some bird.

Indian Chipmunks

Indian chipmunks are commonly known as Indian palm squirrels or three-striped squirrels that are only found in India and Sri Lanka. They are also rodents and belong to the family of Sciuridae. They are very similar to five striped palm squirrels that are biologically known as F. Pennanti and mostly the range of former Indian chipmunks or Indian palm squirrels overlaps with the latter. In the early 19th century they were transported from India and were introduced in places like Australia, Mauritius, Comoro Island, Seychelles, Madagascar and they proved to be minor pests over the years. The size of a palm squirrel is similar to that of a chipmunk but its tail is a little shorter than the body and is bushy in nature. They are generally grayish-brown in colour with prominently visible white stripes running down from their neck to tail in the horizontal direction. Whereas, the other two strips on the other side of the body are stretched from its forelegs to the hind leg. It has a creamy white belly with intermixed long black and white hair covering the tail. Their ears have a triangular shape and the young ones have lighter colour that darkens with age. Their gestation period lasts for 34 days and the breeding takes place during autumn in the grass nest. Two to three litters are common with an average of 2.7. The young palm squirrels appear at 10 weeks and it takes about nine months from that time for these squirrels to become sexually mature. A fully adult weighs about 100 gms and generally lives about 5.5 years in captivity. 

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Taxonomy and Systematics

Chipmunks fall under a single classification and that is stated as a single genus called Tamias. Also, they are then subdivided into three categories and stated as genera, where Tamias classifies eastern chipmunks that are only living chipmunks under this category. Next is Eutamias that incorporates the Asian or Siberian chipmunks that are only living chipmunks under this category and the remaining 23 species mostly found in the west fall under the Neotamias category. All these divisions in chipmunks are treated as sub-divisions of their genera as they are similar in their form and structure. Thus all the taxonomy studies over the 20th century resulted in placing all varieties of chipmunk under a single category of the genus. But as far as their mitochondrial DNA studies are taken into consideration, they vary among each other and thus the chipmunks that fall under the three categories are subjected to genetic differences that are similar to the difference between Marmota and Spermophilus. Their name first appeared in a native place named Odawa as “chipmunk” which means red squirrels.

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Food (Chipmunk Eating Habits)

Chipmunks are basically omnivorous in nature, which indicates that it feeds on both plants as well as animals. Their primary diet includes trees, shoots, and other parts of plants where their primary choice of food includes nuts, seeds, fruits, and buds. They also survive on fungi, insects as well as arthropods, worms, bird eggs as well as small frogs. They might as well sometimes include small newborn birds as part of their diet. Around rural or suburbs with human presence, they are fed on grains and vegetables cultivated by humans and also damage farms and gardens and are therefore considered as pests often. Chipmunks prefer to be on the ground most of the time but they climb trees to fetch nuts such as acorns or hazelnuts. By the arrival of autumn, they start piling the foods that are non-perishable in nature and hide them in their burrows in a larder and the remaining few in the nest that are meant for early consumption. This stocking of food is done in a way that it feeds them till the next spring season arrives. The large internal cheek pouches allow the chipmunks to stuff food in them either to carry it to the burrows for stocking or for the purpose of consumption.  

Chipmunkinator

A chipmunkitors is a unique medium-sized metallic trap that is specially designed to catch chipmunks by alluring them with food like nuts or sunflower seeds around the trap. The average size of these chipmunk catchers is around 14 inches in length and breadth and almost 4.5 in height. These are made in such a way that it is capable of catching multiple chipmunks in a matter of a few hours. These are also inbuilt with two easy passages for in and out so that once caught, they can easily be released to the nearby area.

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