Squirrels display a wide spectrum of coat colors. While often associated with gray, these animals exhibit diverse hues across and within species. This fur diversity helps them adapt to their environments.
The Spectrum of Common Squirrel Colors
The Eastern Gray Squirrel (Sciurus carolinensis), widely observed in North America, has a coat of salt-and-pepper gray and black hairs. Their undersides are white or off-white, and their bushy tails have a slightly darker gray or brownish tint with white-tipped hairs. This coloration helps them blend with tree bark. Though predominantly gray, individuals display brownish or reddish tones.
The American Red Squirrel (Tamiasciurus hudsonicus) has a rusty red to reddish-brown coat. These smaller squirrels have a white or creamy belly and exhibit a black stripe along their sides during summer. Their fur color varies seasonally, appearing more olive-gray, and they develop reddish-brown ear tufts in winter.
Fox Squirrels (Sciurus niger) showcase highly variable coloration. Their coats range from reddish-brown or orange to a mixture of gray and reddish-yellow on their backs and sides. They have reddish-yellow or pale orange bellies and tails. Depending on geographic location, fox squirrels also appear in black or brown color phases.
Rare and Unusual Colorations
Beyond common hues, squirrels exhibit rare colorations due to genetic variations. Albinism, a complete lack of melanin production, results in pure white fur and pink eyes. This rare genetic mutation makes albino squirrels vulnerable due to poor camouflage and light sensitivity.
Melanism is the opposite condition, an overproduction of melanin that causes entirely black fur. Black squirrels are not a separate species but are melanistic forms of common species like the Eastern Gray Squirrel or Fox Squirrel. Their fur is jet black or brownish-black, depending on genetic makeup.
Another white coloration is leucism, a partial reduction in all types of pigment, rather than a complete absence of melanin. Leucistic squirrels have white fur but retain normal, dark-colored eyes, distinguishing them from albinos. Their white coats appear patchy or dirty white, depending on pigment reduction.
Why Squirrels Come in Different Hues
Diverse squirrel coloration is determined by genetics. Genes control the production and distribution of pigments: eumelanin creates black and brown tones, and pheomelanin is responsible for red and yellow hues. Mutations in specific genes, such as the MC1R gene, alter the amount of pigment deposited in their hair, creating different color morphs.
Environmental factors shape squirrel coloration through natural selection. A squirrel’s coat color provides camouflage to avoid predators like hawks and owls. Gray squirrels’ coloration provides camouflage against tree trunks, while reddish squirrels find concealment among leaves.
Regional differences in habitat and climate favor certain color variations. Black squirrels, for example, are prevalent in northern and colder regions, as darker fur offers a thermal advantage by absorbing more sunlight for warmth. This adaptation allows certain color morphs to thrive in specific environmental conditions. Interbreeding between different squirrel species, such as Eastern Gray and Fox squirrels, introduce variant pigment genes, contributing to color diversity.