During the colonial era, eastern gray squirrels were found throughout New York State in large numbers. The variety of hardwood trees in the region made it an ideal habitat for them. Some areas of New York had so many squirrels during that time that farmers even considered them pests. People would occasionally report seeing large groups of squirrels traveling across the countryside, eating everything in sight. But over time, deforestation and hunting greatly reduced their numbers. And by the mid-1800s, spotting a squirrel in New York City was such a rare occurrence that crowds would sometimes form if one was seen on a city street.
However, in the late 1800s, squirrels were reintroduced to American cities in an attempt to bring more “nature” into urban parks and natural areas. These efforts were ultimately successful, though there were challenges along the way. City-managed culls periodically thinned squirrel numbers through the years. And in the 1870s people began trying to remove them from parks again, believing that squirrels were harming local bird populations. Still, squirrels managed to find a foothold in the city. By the mid-1880s, there were an estimated 1,500 squirrels in Central Park. Today they can be found in parks throughout the five boroughs.
Eastern gray squirrels can grow 9 to 12 inches in length and reach two pounds upon sexual maturity. Despite their name, they come in a variety of colors, and will often display a mix of gray, brown, black, and cinnamon fur. Their long-haired, bushy tails can grow to be roughly as long as their bodies.
The squirrel population in North America was once mostly made up of dark-colored squirrels, as darker colors allowed them to remain hidden from birds of prey in the air. However, their dark colors made them more visible from the ground, and much easier for human hunters to spot. As human hunting increased, it is believed that squirrels’ coats grew lighter as an evolutionary defensive response. The light grays and browns that their fur now features keeps them camouflaged from predators both on the ground and in the sky.
Gray squirrels reach sexual maturity at 12 months and can mate up to twice a year. One mating season is in late winter, and the other is in mid-summer, depending on food availability. Multiple males chase a female during courtship, with the most dominant male ultimately mating with the female. The young are born blind and hairless. Their eyes begin to open after approximately 28 to 35 days. When they are 42 to 49 days old their furry coats fully develop and they begin to venture from the nest.
Since eastern gray squirrels usually live in trees, they prefer woodland areas that are primarily made up of oak and black walnut trees. Eastern gray squirrels generally live either in dens made in the cavities of healthy trees, or dreys, which are nests made of twigs and leaves that are constructed high up on tree branches. During periods of severe cold, eastern gray squirrels can stay in their dens or nests for several days at a time, only coming out to visit their stores of food. The average life expectancy for an adult squirrel is six years, and the records for maximum lifespan are 12 years in the wild and 20 years in captivity.