Chipmunks are small, striped ground squirrels common in North American woodlands and suburban areas. A baby chipmunk, or pup, changes dramatically in appearance as it develops. Understanding what pups look like depends heavily on their age, ranging from a helpless neonate to a recognizable miniature adult. We can distinguish these young animals by observing their development inside the nest and their identifiable markings once they become mobile.
Appearance Immediately After Birth
Newborn chipmunks are born in underground burrows and are dependent on their mother. These pups are exceptionally small, often described as being around the size of a bumblebee or no more than 2.5 inches long. They are born blind, with sealed eyes, and are entirely hairless, giving them a pink and fragile appearance. The young are unable to regulate their own body temperature or move independently during this stage.
The distinctive features of a chipmunk begin to appear quickly, even before the pup leaves the nest. Although born naked, the characteristic stripes start to become visible on the skin by about the eighth day. Over the next few weeks, a coat of fur begins to grow, and their eyes typically open around the four-week mark. For the first four to six weeks, these young animals remain hidden within the burrow system.
Identifying Features of Juvenile Chipmunks
The juvenile stage begins when the young chipmunk first emerges from the burrow, usually between five and seven weeks old. At this point, the pups are fully furred and resemble smaller versions of the adults. Their body coloration is a reddish-brown with a white or gray underside.
The most recognizable feature is the pattern of stripes, which is clearly defined across their back and face. The Eastern Chipmunk displays five dark stripes on its back: a single black stripe down the center and two black stripes on each side, separated by a light-colored stripe. They also exhibit light and dark stripes that run across their face, particularly around the eyes.
While they possess the classic chipmunk appearance, juvenile proportions differ slightly from a mature adult. Their tail is shorter and less bushy than that of a fully grown chipmunk. At this stage, they are fully weaned and begin taking short, exploratory trips outside the den to forage. They become fully independent and disperse from the parental territory around eight to ten weeks of age.
Distinguishing Baby Chipmunks from Other Rodents
The presence of characteristic stripes is the most reliable way to differentiate a juvenile chipmunk from other small rodents, such as mice, voles, or baby tree squirrels. Mice and voles lack stripes on their bodies or faces. Mice typically have a nearly hairless tail about the same length as their body, whereas the chipmunk’s tail is hairy and slightly flattened.
Voles are stockier than chipmunks and have almost concealed ears and very short tails relative to their body size. The chipmunk’s ears are small, rounded, and distinctly visible. Baby tree squirrels, such as the Eastern Gray Squirrel, are larger than chipmunks and do not have stripes on their body. A juvenile chipmunk’s stripes extend onto the head, which also distinguishes it from ground squirrels that only have stripes on their body.