Nose and feet of a star-nosed mole. Photo by Enrique Kusawake
When I was a youngster living in a Rochester suburb, I was introduced by my father to one of the strangest animals I have ever met.
My father found this little mouse-like creature in the bottom of a backyard garbage pit and he was able to get it into a pail where it then sat quietly. What was so strange about the critter was its fantastic nose. This protuberance was almost as large as the animal's head. It looked to me as though it had a pink daisy or a pink octopus attached there. (Actually it was like an icosikaidipus as there were 22 tiny pink "arms".)
When my dad and I finally managed to draw our attention away from that amazing schnoz, we noticed that the animal also had outsize front paws with claws that were clearly designed for digging and that its eyes were completely covered with fur. It was apparently a mole.
But had this mole suffered some kind of injury that caused its nose to inflate in this odd way? We had no idea. To find out, my father called the Rochester Museum of Science, where his call was directed to the curator of mammology. When dad described the creature, the curator immediately knew what it was: a star-nosed mole.
He told us that the nose substituted for the mole's eyesight since it is functionally blind. It is a very sensitive apparatus that identifies its prey - worms, insects and crustaceans - by smell and touch.
We don't notice this mole the way gardeners do the somewhat larger Eastern mole as it doesn't raise those unsightly ridges across our lawns. The star-nosed mole does dig tunnels but they are much smaller and therefore rarely seen.
The museum curator urged us to release the mole uninjured as it is, he told us, a beneficial little animal, virtually none of its diet any kind of plant food. We followed his instructions and watched it as the released animal raced off and within a few seconds dug into the ground, soon disappearing under a rock in my mother's garden.
I have since learned much more about this interesting animal. That nose has even made it into the Guiness Book of Records as it makes it the world's fastest forager. So fast does it process information that it only takes about .025 seconds for sensory input to reach the brain. That's 1/26 of the time it takes us to start our foot toward the brake pedal when something appears in front of our car. The reason this mole is able to react so rapidly: almost half of its brain is given over to processing information received from those tentacles.
Once it captures its prey it gobbles it down rapidly, comsuming up to a half dozen insects at the same time. To assist in this, the mole's unusual front teeth act like scissors, allowing them "to grasp small prey precisely," according to researcher Kenneth Catania. He adds that all of these advantages pay off "where small prey animals are abundant, as is often the case in the marshy areas that the star-nose inhabits."
This rapid processing is important to the mole as most of its food is tiny and it takes many of these bite-sized prey to fill in its diet. Larger animals can spend more time killing a rabbit or deer because when they do so they have much more to eat. The mole has to act faster. Researchers call this factor prey profitability and it explains much about this mole's life style. That is not to say, however, that the mole would avoid larger prey like a juicy earthworm.
And now Catania and Fiona Remple have found that this mole (and most likely the water shrew as well) can follow scent underwater, something previously thought to be impossible. They made this remarkable discovery by dragging an earthworm through water and then filming the mole as it followed the scent trail with a 500-frames per second video camera.
The film showed that the mole emits tiny bubbles from its nostrils. These bubbles are then drawn back into the nose, having picked up the scent of the prey it is following.-- Gerry Rising