Eastern Gray Squirrel

Fascinating facts about the Eastern Gray Squirrel

• Since 2016 the eastern gray squirrel has been on the EU's Invasive Alien Species list, meaning it cannot be imported, bred, transported, commercialized, or intentionally released anywhere in the Union. This legal block reflects how the squirrel, once introduced to Europe, has outcompeted native reds and spread rapidly across parks and woodlands, reshaping local ecosystems.
• Black, melanistic squirrels lose 18% less heat at −10 °C, cut their basal metabolic rate by 20%, and boost non-shivering thermogenesis capacity by 11% compared with the common gray form. The darker coat comes from an incomplete-dominant MC1R mutation, and these physiological tweaks let black squirrels survive colder winters.
• Females can breed twice a year, but only 36% manage two litters in a food-rich year; in lean years none do. Estrus draws up to 34 males from as far as 500 m, and the gestation lasts about 44 days. Litters are one to four pups, with a maximum of eight, and kits weigh just 13-18 g at birth, reaching adult size by nine months. These tight reproductive windows tie squirrel numbers directly to mast years of seed-producing trees.
• A partial humerus and two tibiae from the Ardis site in Harleyville, South Carolina, are from a site whose surrounding material dates to 18,940-18,530 years ago, placing eastern gray squirrels in a Late Pleistocene hardwood-conifer swamp. This fossil is anatomically identical to modern specimens.
• In the wild eastern gray squirrels live about six years on average, with a maximum recorded lifespan of 12.5 years, while captive individuals can exceed 20 years. Early mortality is high, only one in four kits survive their first year, so longevity hinges on avoiding predators and disease.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia

At a glance

About the Eastern Gray Squirrel

As the eastern gray squirrel darts through the forest, its bushy tail flicking behind it like a metronome, it embodies the very essence of agile adaptability, its nimble feet barely touching the ground as it weaves a intricate path through the underbrush. With an insatiable curiosity and a penchant for mischief, this diminutive creature is a master of its domain, its large, round eyes gleaming with intelligence as it navigates the complex social hierarchies of its woodland world. In its effortless, fluid motions, the eastern gray squirrel is a testament to the enduring power of evolution, a living, breathing embodiment of the wild beauty that surrounds us.

Eastern Gray Squirrel photographed on Feravox

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