Squirrels are a familiar sight in many backyards. Observing them during reproductive changes can be fascinating, and identifying a pregnant squirrel requires careful observation of subtle shifts in their physical appearance and behavior.
Physical Indicators
A noticeable change in a squirrel’s abdomen is often the first physical sign of pregnancy. As gestation progresses, the belly becomes rounder and more distended, appearing fuller or heavier. This distention can make the squirrel look like it has swallowed a small fruit, and in advanced pregnancy, the belly may even appear to brush the ground when the squirrel walks or touches a branch when sitting upright.
Another indicator of pregnancy is the increased prominence of the nipples. Typically small and difficult to see, a pregnant squirrel’s nipples can become more visible, swollen, or darker. This change is particularly noticeable if the squirrel has had previous litters or is nearing birth, as the nipples prepare for nursing. A general increase in body mass can also be observed, making the squirrel appear heavier or bulkier overall.
Behavioral Clues
Pregnant squirrels often exhibit increased foraging activity, spending more time gathering food to support the developing young and prepare for future lactation. They may appear more focused and diligent in collecting nuts, seeds, and other food items to build up reserves. This heightened appetite indicates increased energy demands.
Increased nesting activity is another strong behavioral clue. Squirrels will diligently carry leaves, twigs, moss, shredded fabric, or other soft materials into tree cavities or dreys to construct or reinforce their nests. They may even prepare multiple nests as a precaution. As pregnancy advances, squirrels might also become less agile and may spend more time resting due to increased weight and energy demands.
Gestation and Nesting
The gestation period for common squirrel species, such as the Eastern Gray Squirrel, typically ranges from 40 to 60 days. Following this period, a litter of young, called kits or pups, is born.
Litter sizes for squirrels range from two to eight young, with three to four kits being common. Squirrels build their nests, known as dreys, in various locations, including tree branches, tree cavities, or occasionally in human structures like attics or sheds. Squirrels have two litters per year, with the first born in late winter or early spring (March-April) and the second in late summer or early fall (July-August).