Squirrels, particularly common tree species, typically produce young twice a year. This results in two distinct birthing windows rather than a single point on the calendar. This biannual pattern maximizes their reproductive success based on food availability and favorable weather conditions.
The Dual Birthing Seasons
Female squirrels, particularly the Eastern Gray Squirrel, can produce two litters annually. The first breeding season occurs between December and February, resulting in births in late winter or early spring, generally February through April. This early cohort benefits from the increasing warmth and new spring resources.
The second breeding period begins around May through July, with the second litters born from August to September. The gestation period for a squirrel is short, lasting approximately 44 days. Litter sizes typically range from two to five pups, though a female can produce up to eight young.
Species and Location Differences
The precise timing of birthing seasons shifts depending on the species and geographical location. In warmer, southern regions, the breeding season may start earlier, and the second litter is often more consistently produced due to a longer period of food availability.
Species differences also introduce variation, such as between the Gray Squirrel and the American Red Squirrel. Red Squirrels, found in northern latitudes, often produce only a single litter each year to align with the shorter summer season. Their breeding schedule is constrained by the persistent cold, demonstrating how local environmental factors limit the two-litter pattern.
Development Milestones
A baby squirrel, called a kit or pup, is born completely dependent, blind, deaf, and hairless. Newborns weigh only about 13 to 18 grams. During the first three weeks, their skin darkens as a fine coat of fur begins to emerge.
Around four to five weeks of age, the pups’ eyes open, allowing them to observe their surroundings. They start exploring outside the natal drey, or nest, at approximately six to eight weeks old, coinciding with the beginning of weaning. Squirrels are typically fully weaned by 10 to 12 weeks of age, possessing the necessary climbing and foraging skills to become independent.
What to Do If You Find a Nestling
Finding a baby squirrel on the ground does not automatically mean it is orphaned, as the mother may be foraging or relocating the litter. If the pup appears uninjured, is warm, and is not crying constantly, attempt to reunite it with its mother. Place the uninjured pup in a small, open-topped box with a heat source, such as a sock filled with warm rice, and secure the container at the base of the nearest tree.
Keep pets and people away from the area and monitor the situation discreetly for several hours, as the mother will likely retrieve the pup once she feels safe. Do not offer the baby squirrel any food or water, as improper feeding can cause severe digestive problems. If the baby is visibly injured, cold, or has not been retrieved after a few hours of daylight, immediately contact a licensed local wildlife rehabilitator for guidance.