During fall, chipmunks and ground squirrels scurry across the ground in search of food as they prepare for winter. But can you tell the difference between the two?
You may think you know a little about chipmunks from the popular “Alvin and the Chipmunks” movies and cartoons. The chipmunks around here don’t have much in common with Alvin, Simon and Theodore, but they do look a lot like 13-lined ground squirrels. They look so much alike it can be hard to tell the difference.
Eastern chipmunks and 13-lined ground squirrels are both rodents, just like mice and rats. They have brown, grayish-brown or reddish-brown fur and are similar in size. Chipmunks are usually about 10 inches long. Ground squirrels range from 6 inches to 12 inches. The biggest difference between the two is the presence of stripes on their heads, or lack thereof. Both have stripes on their backs, but only a chipmunk's stripes continue onto its head. A ground squirrel's stripes end at its neck.
Their stripe pattern can also be used to tell them apart. Ground squirrels are appropriately named for their 13 narrow stripes. The lines are actually alternating stripes, with seven dark brown stripes and six tan stripes. The dark brown stripes usually have tan spots, giving them a dotted appearance. Chipmunks only have five stripes. Their stripes are wider and alternate between brown and tan.
Where you see the animals can also help you decide if it’s a ground squirrel or a chipmunk. Ground squirrels like grassy areas such as yards, cemeteries, golf courses and pastures. They usually avoid wooded areas. Chipmunks prefer wooded areas and forests. They are also often seen along the edges of wooded areas and in yards with plenty of trees and shrubs.
Both chipmunks and ground squirrels are active during the day. Both are also busy at this time of the year as they prepare to hibernate for winter. But only the ground squirrel is a true hibernator. They spend all but three to four months a year underground in their dens.
Chipmunks hibernate too, but not in the truest sense. They spend most their time during winter underground sleeping in their burrows, but they wake to eat every few days.
Chipmunks and ground squirrels are both omnivores, which means they eat both plants and animals. Chipmunks eat primarily seeds, nuts and berries. Ground squirrels eat mainly seeds and plants like corn and wheat. Both occasionally eat insects and small animals.
One key difference between the two is that only chipmunks store food for winter. They'll gather nuts and seeds to keep in their burrows to feast on during winter. Ground squirrels do not wake during their hibernation, so they have no need to store food. Instead, during the fall they double their body weight to increase their fat stores to live off during winter.
While chipmunks and ground squirrels can be hard to tell apart, they are easy to distinguish from another common relative: tree squirrels. With their big, bushy tails, tree squirrels can be readily identified.
Illinois is home to two squirrel species: eastern gray squirrels and eastern fox squirrels. The easiest way to tell them apart is by the fur on their bellies. Fox squirrels have reddish-brown underbellies. Gray squirrels have white underbellies.