Fox squirrel
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| Fox Squirrel | ||||||||||||||||
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| Missing image Squirrel_on_fence.jpg | ||||||||||||||||
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| Sciurus niger Linnaeus,, 1758 |
The Fox Squirrel (Sciurus niger), also known as the cat squirrel or stump-eared squirrel, is the largest species of tree squirrel native to North America.
The Fox Squirrel's natural range extends throughout the eastern United States, excluding New England, north into the southern prairie provinces of Canada, and west to the Dakotas, Colorado, and Texas. They have been introduced into Northern California. While very versatile in their habitat choices, fox squirrels are most often found in forest patches of 400,000 square metres or less with an open understory. They thrive best among trees such as oak, hickory, walnut and pine that produce winter-storable foods like nuts. Western range extensions in Great Plains regions such as Kansas are associated with riverine corridors of cottonwood.
Total body length measures 450 to 700 mm, tail length is 200 to 330 mm, and they range in weight from 500 to 1000 grams. There is no sexual dimorphism in size or appearance. Individuals tend to be smaller in the west. There are three distinct geographical phases in coloration: in most areas the animals are brown-grey to brown-yellow, while in eastern regions such as the Appalachians there are more strikingly-patterned dark brown and black squirrels with white bands on the face and tail. In the south can be found isolated communities with uniform black coats.
Fox squirrels are strictly diurnal, non-territorial, and spend more of their time on the ground than most other tree squirrels. They are still, however, agile climbers. They construct two types of homes, depending on the season--summer dreys are often little more than platforms of sticks high in the branches of trees, while winter dens are usually hollowed out of tree trunks by a succession of occupants over as many as 30 years. Cohabitation of these dens is not uncommon, particularly among breeding pairs. There are two breeding seasons, one peaking in December and the other in June. Maturity is reached after one year and maximum life expectancy is 12.6 years for females and 8.6 years for males.
Fox squirrels depend primarily on tree seeds for food, but they are generalist eaters and will also consume buds and fruits, cultivated grain, insects, birds' eggs, and small lizards. Cannibalism has been reported, but should be considered very rare. In their regular diet of nuts, fox squirrels are classic scatter-hoarders that bury caches of nuts in dispersed locations, some of which are inevitably left unretrieved to germinate.
Fox squirrels are also known for being living fossils, skeletally very similar to remains of the oldest-known squirrel, Protosciurus, from the late Oligocene and early Miocene epochs.
External links
- Mammalian species account (http://www.science.smith.edu/departments/Biology/VHAYSSEN/msi/pdf/i0076-3519-479-01-0001.pdf) of Sciurus niger from the American Society of Mammalogists
- More Photos of fox squirrels (http://www.scarysquirrel.org/current/lovey/fox/pics.html)
- 3D visualization of a fox squirrel skull (http://www.digimorph.org/specimens/Sciurus_niger/) from Digimorph
- Delmarva Fox Squirrel (http://nature-wildlife.com)