Squirrels are a common sight across North America, inhabiting urban parks and natural woodlands alike. These rodents have a seasonal reproductive cycle that aligns with the availability of food and favorable weather conditions. Understanding the timing of their reproductive seasons provides clarity on when to expect the appearance of their young, which is important for observing wildlife. For the most common species, the timing of squirrel births is a predictable pattern that repeats twice a year.
Peak Birthing Seasons by Species
The most widely distributed North American species, the Eastern Grey Squirrel (Sciurus carolinensis) and the Fox Squirrel (Sciurus niger), generally follow a pattern of two birthing windows per year. The first birthing period begins in late winter or early spring, resulting from a mating season that starts around December or January. For the Eastern Grey Squirrel, this typically means a litter is born between February and March. The second birthing window occurs in the summer, usually between July and September, following a second mating period in May or June.
This biannual timing, however, can vary based on local conditions like geography and climate. In warmer southern regions, the breeding season may begin earlier, while in northern latitudes, the entire cycle might be slightly delayed. A female’s gestation period lasts about 40 to 45 days. The mother gives birth to a litter, often referred to as kits, which typically consists of two to four young. The female squirrel will usually produce one to two litters per year, with the occurrence of a second litter often depending on the abundance of food resources.
Identifying Developmental Stages
When first born, a baby squirrel is in a highly vulnerable state, appearing pink, blind, and completely hairless. These newborns weigh only about 13 to 18 grams and are entirely dependent on their mother for warmth and nourishment. Over the next few weeks, significant physical changes take place.
Fur begins to grow shortly after birth, and by three to five weeks of age, a thin coat of soft fur is noticeable. The eyes, which were sealed shut at birth, begin to open typically around four to five weeks. The ears also open around three to six weeks. The kits remain in the nest, or drey, until they are approximately eight to ten weeks old. At this point, they begin to explore and climb outside the nest, though they will not be fully independent until about 12 to 16 weeks.
Practical Steps When Finding a Baby Squirrel
Finding a baby squirrel on the ground does not automatically mean it has been orphaned, as a mother squirrel may be nearby or retrieving a fallen kit. The first step involves assessing the situation and giving the mother an opportunity to reclaim her young. If the baby appears uninjured and the weather is warm, it can be left alone while being monitored from a safe distance, as the mother will not approach with humans or pets nearby.
If the baby is cold, or if it is late in the day, the priority shifts to keeping it warm, as a cold baby will not be retrieved by its mother. A temporary container like a small box lined with a soft cloth can be used, with a heat source such as a warm water bottle placed underneath the cloth to prevent direct contact and burns. It is important not to give the baby any food or water, as an incorrect diet can be harmful. If the mother does not return within a few hours or by nightfall, or if the baby appears injured or sick, contact a local licensed wildlife rehabilitator for guidance and professional care.