Stripes are interesting patterns inherent to rodents like hamsters and chipmunks. The presence of black, brown, or white stripe patterns on chipmunks is the quality that sets them apart from squirrels, their close relatives.
But why do chipmunks have stripes?
There are several theories and studies that justify the appearance of stripes on chipmunks. One of the most accepted explanations is gene mutation brought by evolution through millions of years.
Interestingly, these distinctive markings go beyond aesthetics—they also serve various purposes essential to the creature’s survival.
Let’s learn the science behind these critters’ unique markings, their role in survival, and how these stripes compare for every chipmunk’s species.
What Do Chipmunks’ Stripes Look Like?
Chipmunks are fast-moving rodents with big, glossy eyes, plump cheeks, and erect, fuzzy tails. These omnivores are four to seven inches tall, only slightly taller than a teacup.
One feature that makes these critters stand out is the stripes that line their backs, sides, and faces.
These stripes appear as combinations of contrasting colors, like white, light brown, and black. However, the chipmunks’ stripe patterns and colors can vary depending on their fur color and species.
For example, the Eastern chipmunk, the most common species found in the US, has a reddish-brown coat.
Their coat is lined with black-white-black stripe patterns on both sides, from the neck down to the base of the tail. They also have white and black stripes lining both eyes.
How Did Chipmunks Get Their Stripes?
Did you know there’s a fascinating old legend about how chipmunks got their stripes?
According to a Native American tale, the chipmunk’s striped pattern results from its struggle with a bear who got furious after the tiny mammal repeatedly teased him.
Legend has it that the angry bear clawed the chipmunk’s back after attempting to escape from the bear’s grasp.
Therefore, it resulted in the striped mark on its back that its descendants carry today.
While it’s an exciting bedtime story to lull kids to sleep, science tells us that a chipmunk’s stripes result from proteins that alter the expression of pigment-producing cells in the chipmunk’s body.
The Science Behind Chipmunks’ Stripes
According to a study led by Harvard University professor Hopi Hoekstra, the chipmunks’ stripes are due to the Alx3 gene that suppresses the activity of melanocytes on some parts of the rodent’s body.
But what does this mean?
The melanocytes are pigment-producing cells in charge of giving color to the chipmunk’s coat. In order to bring color to the fur, the melanocytes must reach a certain level of maturation.
What happens is that the Alx3 gene present on the chips’ DNA stops the melanocytes from maturing. That’s why no pigment is produced on some parts of its fur.
In effect, you’ll notice how chipmunks have varying degrees of colors in their stripes. You can see white, light brown, and black striped patterns.
The team of researchers found this remarkable breakthrough after studying the African striped mouse, which is a close relative to chipmunks.
What’s the Significance of Chipmunks’ Stripes?
Some theories suggest that chipmunks’ stripes play a role in mating and communication, but there isn’t enough scientific evidence to back these claims.
So, let’s find out how the presence of striking patterns is useful as camouflage and in identifying chipmunks from other rodents.
Camouflage and Evasion From Predators
Chipmunks are diurnal creatures, which means they’re most active during the daytime. That makes them eye candy for predators like hawks, raccoons, and foxes that roam in broad daylight.
It’s during unwanted encounters that the striped fur is most helpful for these tiny creatures.
Since they live in wooded areas, forests, and among bushes, the presence of stripes increases their survival advantage as it helps blend them into their surroundings.
The stripes are the ideal camouflage, and hiding among fallen leaves, trees, and thickets is a no-brainer for these critters. That way, they can evade even the sharpest prey.
Distinction From Other Rodents
Chipmunks descend from the squirrel family, and the presence of stripes is one significant feature differentiating them from the almost similar-looking squirrels.
Unlike chipmunks, squirrels are larger (10 to 15 inches tall) with longer tails. While chipmunks typically have brown fur with stripes, squirrels’ coats are commonly gray-black colored and silky.
Do Chipmunks Have Different Stripe Patterns?
Yes, no two stripes are entirely the same!
In fact, the strength and contrasts of colors as well as the arrangement of stripe patterns vary per chipmunk species.
Let’s compare the Eastern chipmunk with the Siberian chipmunk as an example. The Siberian chipmunk is the only species (out of 25) not native to Northern America.
Compared to the Eastern chipmunk, Siberian chips have four to five longitudinal black and white stripes lined along their backs.
On the other hand, Eastern chipmunks have a distinct black line on the middle of their backs and black-white-black stripes along their sides.
Are Chipmunks Born With Stripes?
Newborn chipmunks usually don’t have fur. It takes up to two weeks until they start to grow fur, and stripes will start to appear.
Do Chipmunks Lose Their Stripes?
Chipmunks retain their striped patterns throughout their lifespan, but they may grow faint (but not entirely disappear) when their coat goes through seasonal change, especially during winter.
Final Thoughts
Chipmunks have stripes due to the presence of the Alx3 gene that controls the production of pigment in their fur.
As a result, chipmunks have unique white, black, or brown lines along their backs or faces.
Ben has a bachelor’s degree in construction engineering. When not constructing or remodeling X-Ray Rooms, Cardiovascular Labs, and Pharmacies, you can find him at home with wife and two daughters. Outside of family, He loves grilling and barbequing on his Big Green Egg and Blackstone Griddle, as well as working on projects around the house.
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