Star-nosed mole facts for kids
Quick facts for kids Star-nosed mole |
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| Conservation status | |
Scientific classification  |
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| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Eulipotyphla |
| Family: | Talpidae |
| Genus: | Condylura |
| Species: |
C. cristata
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| Binomial name | |
| Condylura cristata (Linnaeus, 1758)
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| Star-nosed mole range | |
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| Synonyms | |
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Sorex cristatus Linnaeus, 1758 |
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The star-nosed mole (Condylura cristata) is a small, unique mole that lives near water in North America. It is famous for its amazing nose, which looks like a star. This special nose helps it find its way and hunt for food.
This mole is about the size of a hamster. Its star-shaped nose has more than 25,000 tiny touch sensors called Eimer's organs. These organs help the mole feel its surroundings. They can even detect small vibrations in the ground.
The nose is about 1.5 centimeters wide. It has 22 fleshy "fingers" or appendages, each covered with Eimer's organs. Other moles also have these organs, but not as many or as specialized as the star-nosed mole. Since these moles cannot see well, their nose is super important for finding food.
Scientists have found that the star-nosed mole is one of the fastest eaters in the world! It can identify and eat a piece of food in as little as 120 milliseconds. That's faster than the blink of an eye! Its brain decides if food is edible in about eight milliseconds. This incredible speed is almost the fastest possible for a mammal's brain.
These moles can also do something very unusual: they can smell underwater. They do this by blowing tiny air bubbles onto objects. Then, they quickly inhale these bubbles to carry scents back to their nose.
Contents
Where Star-Nosed Moles Live and What They Eat
Star-nosed moles prefer to live in wet, low-lying areas. You can find them in marshes and near streams and ponds. They are excellent swimmers and can search for food along the bottom of watery places. Like other moles, they dig shallow tunnels. Often, these tunnels open up underwater.
They are active both day and night. Even in winter, they stay busy, digging tunnels through snow and swimming in icy streams. These moles are very good at keeping their body warm, even in cold water. This helps them survive in chilly environments. Scientists believe they might live in groups, but more research is needed to understand their social lives.
The star-nosed mole eats many small creatures. Their diet includes aquatic insects like caddisfly larvae and midges. They also eat worms, such as earthworms and leeches. Other foods include snails, small crustaceans, tiny amphibians, and even small fish. Sometimes, they are found in drier grassy areas, too. They have been seen in mountains as high as 1,676 meters.
Life Cycle and Reproduction
Star-nosed moles usually mate in late winter or early spring. The female mole typically gives birth to one litter of four or five young. This happens in late spring or early summer. If the first litter doesn't survive, a female might have a second one.
When they are born, the babies are about 5 centimeters long and have no hair. They weigh about 1.5 grams. Their eyes, ears, and even their star-shaped nose are closed. They open and become useful around 14 days after birth. Young moles become independent after about 30 days. They are fully grown and mature when they are about 10 months old.
Many animals hunt star-nosed moles. These predators include red-tailed hawks, great horned owls, and barn owls. Foxes, weasels, minks, and various skunks also prey on them. Large fish like the northern pike and even domestic cats can also be a danger to them.
How the Star-Nosed Mole Uses Its Nose
A scientist named Kenneth Catania has studied star-nosed moles for many years. He compares the mole's snout to how we use our eyes. When the mole touches something that might be food, it quickly moves its nose. It uses the two smallest rays, called ray number 11, to touch the object repeatedly.
Catania found that these nose movements are like our "saccadic" eye movements. These are the quick movements our eyes make when we look from one point to another. The mole's brain gives extra attention to the 11th rays, just like our brain focuses on the center of our vision for sharp details. This shows that evolution often finds similar solutions for creating very sensitive sensory systems. It uses a wide area for scanning and a small, super-focused area for important details.
The star-shaped nose is truly unique. Since star-nosed moles live in complete darkness, they rely on their amazing nose to find and identify prey. They don't use their eyes much, as moles have very small eyes and tiny optic nerves. This special organ is known for being incredibly sensitive and fast. It can decide if something is edible in just eight milliseconds. This makes the star-nosed mole the world's fastest forager, according to the Guinness World Records.
The Star: A Super-Sensitive Touch Organ
The star-nose is a highly specialized organ. It has 22 fleshy, finger-like parts, or tendrils, that surround the mole's nostrils. These tendrils are always moving as the mole explores its environment. The star itself is about 1 centimeter across, a bit smaller than a human fingertip.
This structure is divided into a central, very sensitive area (the 11th pair of rays) and less sensitive outer areas. The star acts like a "tactile eye." The outer rays (1 to 10 on each side) scan the surroundings. When they find something interesting, they direct the 11th ray to touch it for more detail. This is similar to how a primate's eye focuses on an object.
These tendrils do not have muscles or bones. Instead, they are controlled by tendons connected to the skull. Their job is purely mechanical, meaning they are for touch. The star is covered with about 25,000 tiny raised bumps, called Eimer's organs. These organs are the only type of touch receptor found on the star. This proves the star is designed for mechanical sensing.
Eimer's organs are found in almost all mole species. However, no other mole has as many as the star-nosed mole. This huge number of special receptors makes the star incredibly sensitive. It is about six times more sensitive than a human hand, which has about 17,000 receptors. Each Eimer's organ has many nerve fibers. This means the star is packed with nerves, sending touch information quickly to the brain.
More than half of the mole's brain is dedicated to processing information from its nose. This is amazing because the nose is only about 10% of the mole's body size. It shows that the nose acts like the mole's eyes, creating a touch map of its environment.
Smelling Underwater
The star-like nose also helps the mole smell underwater. This was once thought impossible for mammals. Mammals usually need to breathe in air to smell. But the star-nosed mole has a clever trick. It blows 8 to 12 tiny air bubbles per second onto objects or scent trails. Each bubble is very small, about 0.06 to 0.1 millimeters in size.
Then, the mole quickly sucks these bubbles back into its nostrils. This carries the scent molecules from the water into its nose. Scientists have observed that the moles blow these bubbles directly towards potential food. Before the star-nosed mole, no one believed mammals could smell underwater, especially by blowing bubbles!
Adaptations
The star-nosed mole has incredible adaptations! Its unique star-shaped nose helps it find and eat food incredibly fast, even underwater, because the mole is almost blind.
Scientists believe the star-nose developed over a very long time because it gave the moles a big advantage in their wetland homes. Wetlands are full of tiny insects and worms. To find and eat these small prey efficiently, the moles needed a super-sensitive way to explore their environment. The star-nose, with its thousands of touch sensors, was the perfect solution. Scientists have counted between 106,000 and 117,000 nerve fibers in the entire star. This allows touch information to reach the brain very fast. The mole's brain can decide if something is edible in just 25 milliseconds. This includes 12 milliseconds for the brain to respond to touch and 5 milliseconds for the mole to react. For humans, this whole process takes about 600 milliseconds!
These moles are very good at keeping their body temperature just right, even in cold water. This helps them thrive in their chilly, aquatic homes.
Predators
Even with all their amazing adaptations, star-nosed moles have predators. These include birds like hawks and owls, foxes, weasels, minks, skunks, and even large fish like northern pike. Domestic cats can also be a threat.
How the Star-Nose Evolved
The unique star-shaped nose likely developed over a very long time. Scientists believe that early moles might have had small bumps on their snouts. Over many generations, these bumps grew into the elaborate star we see today. While there isn't much fossil evidence, many moles today have Eimer's organs on their snouts.
One theory suggests the star evolved because of the mole's wet habitat. Wetlands have many small insects. To find these tiny creatures efficiently, moles needed a super-sensitive touch organ. The soft, muddy soil of wetlands is also less harsh than dry soil. This allowed the delicate star to develop without being damaged by constant digging.
Another theory explains the mole's incredible foraging speed. In wetlands, individual prey items are often very small and don't provide much energy. By eating extremely fast, the star-nosed mole can make up for the low nutritional value of each meal. This maximizes the time it has to find more food. The star-nose is also very close to the mouth. This greatly reduces the time it takes to grab and eat food. The mole also has special front teeth, like tiny tweezers, to pluck small prey from the ground. These teeth and the star likely evolved together to help the mole find and eat small prey quickly.
See also
In Spanish: Topo de nariz estrellada para niños
