Critters of North Idaho: Yellow-Pine Chipmunk
Those rascally, bushy-tailed squirrels aren’t the only rodents running around and collecting nuts. Very similar in appearance, chipmunks do very much the same thing. But don’t confuse the two just because they look alike! As we’re about to find out, chipmunks are quite distinguished from their squirrly cousins.
The first thing you should know about chipmunks is that, technically speaking, they’re really a type of squirrel. They belong to the squirrel family (Scuridae), alongside tree squirrels, ground squirrels, groundhogs and prairie dogs.
Chipmunks themselves are not all alike either, as there are 25 different species. Excluding the Siberian chipmunk (guess where it lives!), all of them live in North America. And of these, five species are native to Idaho.
Today, we will be focusing on the yellow-pine chipmunk (Neotamias amoenus). They’re anywhere from 7 to 9 inches in length and tip the scales at about one and a half to almost two ounces.
Interestingly, females tend to be toward the larger end in terms of size. This is unusual for mammals. Usually it’s the other way around, where the males are larger than the females. Their fur is cinnamon in color, often described as dark and reddish, and several rows of dark and light colored stripes running down the back.
Yellow-pine chipmunks are often neighbors with their cousin, the gray squirrel, which is a type of tree squirrel. You might think that these similar species might compete for resources. But before you start dreaming up cute squirrel versus chipmunk battles, rest assured that these tussles do not happen in the wild.
Each species has adapted to fulfill its own unique ecological niche. To put it another way, chipmunks and squirrels have certain behaviors, and food and habitat preferences that make them able to coexist. This is called niche partitioning.
Another example of niche partitioning you may be familiar with without even knowing it are giraffes and antelope on the African savannah. The giraffe’s long neck enables it to eat from the tallest of trees, while antelope browse on smaller shrubs too short for the giraffe. Giraffes and antelope can coexist in the same habitat because they have different ways of acquiring their food.
The first (and most obvious) difference between gray squirrels and chipmunks is in their appearance. The squirrels tend to be larger and they have big, bushy tails. Chipmunks are smaller and have smaller, less bushy tails.
The most common squirrel in North America is the gray squirrel, and it usually is a solid gray or brown color. This makes it easily distinguishable from chipmunks, which, as mentioned above, have dark and light stripes running down their backs.
While both squirrels and chipmunks can live anywhere from forests to urban areas, chipmunks prefer forests. More specific, yellow-pine chipmunks like to live in temperate, brushy-covered pine forests, but they can also be found in rocky outcrops and grassy areas.
Squirrels like to make their homes in tree crevices. While chipmunks are capable of climbing trees, they live in burrows on the ground. They will also use them to hibernate through the long winter months. The final distinction is their diet.
Both are omnivores. However, squirrels lean more toward the veggie side of the scale, eating larger fruits and nuts from trees than chipmunks do. Yellow-pine chipmunks forage for nuts and seeds, fruit, fungi and insects, but they sometimes supplement this with roots and even bird eggs. Like other chipmunks, they will even stuff food in their cheeks until they are finished foraging.
One important thing chipmunks and squirrels have in common is that they like to stash nuts and seeds in the ground for later. They don’t always go back and find every seed or nut they buried. This means that these plants have the opportunity to grow and reproduce more seeds and nuts of their own. In this way, chipmunks and squirrels do their part in helping make more plants wherever their daily foraging trips should take them.
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