Eastern gray squirrel
The eastern gray squirrel is native to the eastern United States including parts of New York City. The common name of this organism is ‘grey squirrel’ while its scientific name is Sciurus carolinensis. The grey squirrel belongs to the Kingdom Animalia. Grey squirrels can be found in nearly every habitat from tropical rainforests to semi-arid deserts, only keeping away from high Polar regions and very dry deserts. Most gray squirrels live in tree hollows while others construct nests with twigs and plant material. In New York, gray squirrels are mostly found in deep swamps of cypress and magnolia and in dense hammocks of oaks that grow along streams. They are also found in parks like Central park in Manhattan where I live.
Grey squirrels are interesting animals to observe and study. Apart from having a rich and complex range of behaviors, squirrels are easy to observe. They are indigenous to Africa, the Americas, Europe and Asia. In general, grey squirrels range in size from 7-10 cm in length, and 10 g in weight, to 53–73 cm in length, and 5-8 kg in weight. They characteristically have lean bodies with shaggy tails and big eyes. They are primarily herbivorous, feeding on seeds and nuts, but some feed on insects and small vertebrates.
Locomotion: They grey squirrel is usually in an “alert” position most of the time. It raise itself up on its posterior legs, hold its paws up, sniff the air, and then scan its surrounding once or twice. Occasionally, the squirrel breaks into a run starting with an impulsive dash in one direction, often different from the direction it was facing initially. The squirrel runs with its limbs gripping surfaces for support. The grey squirrel is very skilled at jumping and climbing on trees. In order to jump on a tree, the squirrel starts off by running then pushes itself off the ground using its hind legs. The squirrel often lands somewhere around 30 to 50 cm above the ground. It then climbs and clambers up a tree, one paw after the other, moving swiftly without hesitation. When the gray squirrel stops at a branch, it begins to move horizontally towards the top of the branch. The grey squirrel also meanders around. It moves around at a much more leisurely pace when there are no people nearby. Its meandering action involves the squirrel walking to one area, and then adapting an alert position.
Figure 1: The eastern gray squirrel
Feeding/forging: The grey squirrel feeds on nuts, seeds, and wild fruits that grow on trees and others that fall off trees. It picks its food using both forearms, placing each paw firmly on either side of the nut/fruit. The squirrel then brings the item closer to its nose and sniffs it before it attempts to bite it or discard it. When it comes across a heap of leaves or other natural garbage, the squirrel digs through the heap using rapid coordinated movements of its arms. Each arm is often raised above the squirrel’s chest as it plows downwards through the heap in a circular motion.
Social behavior: When disturbed and prior to aggressive interactions, the tail and body hair of the grey squirrel becomes erect. The squirrel also flicks its tail rapidly when alarmed. There is often minimal interaction between the grey squirrels as they feed and move separately and often ignore each other.
Breeding: Grey squirrels breed all through the year, although the peak breeding season is between July and September and again between December and February. Mating is essentially promiscuous as the male squirrels habitually try to mate with any receptive female. The gestation period of these mammals is 40-45 days. The young squirrels remain in the nest for approximately six weeks until their teeth have developed and their eyes are opened. Squirrels are almost adult in size and when they are 6 months old and they are sexually mature between 9 months to 1 year.
References
BBC . (2011). Grey squirrel. Retrieved November 15, 2011, from Nature Wildlife: http://www.bbc.co.uk/nature/life/Eastern_gray_squirrel
Elbroch, M., & Murie, O. J. (2005). PETERSON FIELD GUIDE TO ANIMAL TRACKS. Houghton Mifflin Sch.
Gregg, D. (2009, August). Grey Squirrel. Retrieved November 15, 2011, from Obed Watershed Community Association: http://www.obedwatershed.org/files/The_Grey_Squirrel.pdf
Hamerton, D. (2010). Sciurus carolinensis (Grey Squirrel). Retrieved November 15, 2011, from biodiversityexplorer: http://www.biodiversityexplorer.org/mammals/rodentia/sciurus_carolinensis.htm
Long, K. (1995). Squirrels: a wildlife handbook. Wisconsin, USA: Big Earth Publishing.
