The groundhog, also known as a woodchuck, is a large rodent recognized for its extensive burrow systems. Female groundhogs give birth to their young, called pups or kits, in a prepared den chamber deep underground, typically in late spring following a 32-day gestation period. Because the young are born in the seclusion of the burrow, they are rarely observed in their earliest, most vulnerable stages.
Physical Characteristics at Birth
Newborn groundhogs are entirely dependent on their mother. They are incredibly small, typically measuring only about one inch in length and weighing around 1.5 ounces. These tiny pups are born pink and hairless, with wrinkled skin that makes their appearance distinct from the furry adults.
At birth, the kits are both blind and deaf, as their eyes and ear canals remain tightly sealed. Their only functional senses are touch and smell, which they use to locate their mother and littermates for warmth and nursing. They communicate their needs with soft, high-pitched squeaking noises, ensuring the mother can tend to them within the darkness of the burrow.
Key Developmental Milestones
The physical appearance of a groundhog pup changes quickly within the safety of the den. During the first two weeks, their skin begins to darken, and a coat of short, dark fur starts to emerge, first appearing on their heads. This developing fur provides insulation and marks their transition from a pink, naked newborn.
By approximately four weeks of age, their eyes and ears finally open. At this point, the pups are fully furred, and their coloring begins to resemble the grizzled grayish-brown coat of an adult groundhog. They remain dependent on their mother’s milk, but she also introduces them to soft solid foods, such as grasses and flowers, which she brings back to the den. Full weaning typically occurs around five to six weeks of age.
Emerging from the Burrow
Young groundhogs first venture out of the burrow entrance around five to six weeks old. At this stage, they appear as fully formed, though significantly smaller, versions of the adult groundhog. Their bodies are covered in the dense, coarse, reddish-brown and gray fur characteristic of their species.
The young groundhogs are fully mobile and have the same short, muscular legs and sharp claws designed for digging as their parents. When they first emerge, the pups explore cautiously near the den entrance under the supervision of their mother. They quickly learn to forage independently and, by the time they are two months old, they begin to disperse to establish their own territories.