The most commonly seen squirrel in Eagle Creek Park is the large, reddish-colored Fox Squirrel (Sciurus niger). Gray squirrels are native to Indiana as well, but there are no populations living in Eagle Creek, although they can be found on the campus of Butler University. The smaller Red Squirrels (also known as Piney Squirrels or Chickarees), barely larger than chipmunks, are present in low numbers in the park, and it is possible we have nocturnal Flying Squirrels as well, although their presence has not been officially confirmed.
Fox Squirrels will nest in hollow trees (or sometimes attics), but they also build nests of dead leaves and twigs high in the treetops. These leafy nests are known as dreys, and winter and early spring before the trees leaf out is the best time to see them. (Nests of large birds can be similar in size, but usually don't contain dead leaves.) Summer dreys may be small and loosely constructed, but winter dreys and dreys built by a mother squirrel for raising babies are sturdy, intricately woven, and lined with soft, insulating material. Fox Squirrels in Indiana can have at least two litters of babies per year: one in early spring, and a second in mid to late summer. The first litter is sometimes born as early as February, although the mother squirrels take a gamble with the chance of severe spring weather. Newborn squirrels are pink and hairless, but despite their lack of fluffy squirrel tail, they are still identifiable by their long front toenails.
A litter of baby fox squirrels was found in a gutter of a house a few days ago - the mother apparently nested in the gutter and the babies were washed out by heavy rains. The babies already have fur and have their eyes open, so they were probably born some time in February. Before I sent them to a wildlife rehabilitator, I got a video clip of the babies trying out some solid food for the first time. As you can see, they're still a little wobbly! The babies will be released back into the wild as soon as they are old enough.