Squirrels are a familiar sight in many neighborhoods and natural spaces, known for their agile movements. Their reproductive cycles are a fascinating aspect of their lives, encompassing distinct patterns for breeding and raising their offspring. Understanding these patterns provides insight into how these creatures sustain their populations.
The Typical Squirrel Litter
A female squirrel typically gives birth to a litter ranging from two to five offspring. For eastern grey squirrels, litters commonly contain one to four young, though a litter size of up to eight has been recorded. Similarly, red squirrels usually produce litters of three to five young, with a reported range of one to eight kits. The average litter for red squirrels is around four young.
Litter size can vary based on several factors, including available food resources, and the mother’s overall health and age. Abundant food can lead to larger litters, while scarcity might result in fewer offspring. Younger mothers may have smaller litters compared to older females. Environmental conditions, such as climate and predator presence, can also influence litter size.
Squirrel Breeding Habits
Female squirrels can breed twice annually, with their reproductive activity heavily influenced by food availability. The primary breeding seasons for eastern grey squirrels occur from December to February and again from May to June. Red squirrels also typically have one or two litters each year, often in the spring around April and late summer around August.
The gestation period for squirrels averages about 44 days for eastern grey squirrels. Red squirrels have a slightly shorter gestation, typically between 36 and 42 days. Females have multiple ovulation cycles each year, but are receptive for mating only for a single day during each cycle. Males play no part in raising the young.
Raising the Young
Newborn squirrels are born hairless, blind, and deaf, weighing approximately 13-18 grams at birth. The mother squirrel constructs a sturdy nest, called a drey, providing shelter and protection from predators. These nests can be built from leaves and twigs, often located in tree cavities or leaf nests.
The young remain in the drey, fully dependent on their mother for warmth and nourishment. Their eyes typically open after three to five weeks, and their ears open around three to four weeks postpartum. Young squirrels begin to venture outside the nest around six to seven weeks of age and start consuming solid food. Weaning usually occurs around 10 to 12 weeks, after which the young squirrels gradually become independent.