Rock pocket mouse facts for kids
Quick facts for kids Rock pocket mouse |
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|---|---|
| Conservation status | |
| Scientific classification | |
| Genus: |
Chaetodipus
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| Species: |
intermedius
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The rock pocket mouse (Chaetodipus intermedius) is a small mouse that lives in the deserts of the southwestern United States and Mexico. It is one of 19 different kinds of pocket mice found in the genus Chaetodipus. These mice are special because their fur color often matches the rocks where they live, helping them hide from predators.
Meet the Rock Pocket Mouse
Rock pocket mice are medium-sized, usually about 18 centimeters (7 inches) long. This includes their long tail, which is often longer than their body, about 10 centimeters (4 inches). They weigh around 12 to 18 grams, which is about as much as a few paper clips!
These mice are nocturnal, meaning they are active at night. During the day, they hide in small burrows they dig in the soil. They often dig these burrows close to or under rocks. This helps them stay safe from owls, which are their main predators.
Rock pocket mice mainly eat plant seeds. Their reproduction season usually starts in February or March and lasts for a few months. A mother mouse typically has between three and six babies in one litter.
Why Are Some Rock Pocket Mice Different Colors?
Rock pocket mice live mainly in rocky areas in the desert. Most of them have light, sandy-colored fur. This color helps them blend in with the light-colored desert rocks. It's like nature's camouflage!
However, some rock pocket mice have much darker fur. These dark mice are found living on black, basaltic rock formations. These black rocks are formed from old lava flows. The dark fur helps these mice hide on the dark rocks.
Scientists used to group rock pocket mice into many different types based on where they lived and their fur color.
Nature's Camouflage: Rock Pocket Mice and Natural Selection
In 2003, scientists studied the DNA of rock pocket mice. They looked at both light-colored and dark-colored mice from places like Pinacate Peaks, Mexico, and New Mexico, USA.
They found something very interesting in the mice from Pinacate. The color of their fur was perfectly linked to a specific gene called Mc1r. This gene controls fur color. Mice with one version of the Mc1r gene had light fur, and mice with a different version had dark fur.
This is a great example of natural selection at work! Natural selection is when animals with traits that help them survive and reproduce in their environment are more likely to pass on those traits. For rock pocket mice, blending in with the rocks helps them avoid being eaten by owls.
- On light rocks, light-colored mice are harder to see, so they survive better.
- On dark rocks, dark-colored mice are harder to see, so they survive better.
Over time, this means that the fur color of the mice matches the rocks they live on.
Scientists also found that the dark fur color developed more than once in rock pocket mice. For example, the dark mice in New Mexico had dark fur, but it was caused by changes in different genes, not the Mc1r gene. This is called convergent evolution. It means that similar traits (like dark fur for camouflage) can develop in different ways in different groups of animals, even if they are closely related.
