Squirrels are common across Missouri, inhabiting dense forests, urban parks, and backyards. Their presence is noticeable during spring and summer as they forage and raise their young. The reproductive cycle of these rodents is highly seasonal, closely tied to resource availability and climate. This timing results in new litters appearing twice annually for the state’s most prevalent species.
The Dual Breeding Seasons
Squirrels in Missouri experience two distinct breeding periods annually, resulting in two separate litters for most adult females. The first cycle begins with mating in late December or early January. Following a gestation period of 42 to 45 days, the first pups are born, peaking in late February and throughout March.
This early timing ensures the young are ready to forage independently just as the spring bloom provides abundant food sources. The second breeding cycle commences with mating in late spring, typically from late May through early July. This leads to a summer peak in births, with new litters arriving in July and August.
The female squirrel raises her young alone, using a safe location like a tree cavity or a large leaf nest, known as a drey. Although Eastern Fox Squirrels may start breeding slightly earlier than Eastern Gray Squirrels, the overall pattern of two litters aligns for both species. These dual seasons help maintain a stable population by capitalizing on warm weather and food availability.
Development and Independence Timeline
The young, typically born in a litter of two or three, are highly vulnerable, arriving hairless and unable to see or hear. They depend entirely on the mother’s milk and warmth within the nest for several weeks. Pups begin developing around four weeks old when their ears open, followed shortly after by their eyes.
The eyes typically open fully around five to six weeks, marking a significant developmental milestone. Although still confined to the nest, they quickly gain mobility and coordination. Young squirrels take their first exploratory trips outside the nest or drey when they are about six to seven weeks old.
Weaning generally occurs around 10 to 12 weeks of age, as the young transition from their mother’s milk to solid foods. By roughly three months old (12 weeks), juvenile squirrels are fully independent and disperse from the maternal nest to establish their own territories. This timeline means the first litter becomes independent in late spring, and the second litter achieves independence by late autumn.
Common Squirrel Species in Missouri
The majority of breeding activity belongs to two primary species of tree squirrels: the Eastern Fox Squirrel (Sciurus niger) and the Eastern Gray Squirrel (Sciurus carolinensis). The Eastern Fox Squirrel is the larger species, characterized by its reddish-yellow to brownish-orange coat. Fox squirrels tend to favor more open woodlands, edges, and isolated woodlots, often spending more time foraging on the ground.
The Eastern Gray Squirrel is smaller, identifiable by its predominantly gray coat, white underside, and white-tipped tail hairs. Gray squirrels prefer denser forest cover, such as bottomlands and large tracts of hardwood forest, particularly those dominated by oak and hickory trees. Both species are highly adaptable and thrive in urban environments where mature trees provide ample food and shelter.