This is Mother’s Day weekend and at first I was going to choose something that was a little more “maternal”, but honestly sometimes I get something in my mind and I just start to research it and for some reason I just cannot let it go. That was the case with the star-nosed mole, it is just so amazing that I, not unlike Alice in “Alice in Wonderland”, could not wait to “go down that rabbit hole”.
Neuroscientist Ken Catania has studied the star-nosed mole for three decades. He refers to it as the poster child for extreme evolutionary adaptations. “It’s an incredible creature”, he says “in almost every way I can imagine.” It is considered a true neurological wonder.
I realize the opossum is not the most adorable critter, but the star-nosed mole is even more bizarre looking. Its 4 1/2″ cylindrical form is ideal for moving through soil. It has a relatively long tail as compared to other moles – about 1 1/2″ long. The dark thick fur will bend in all directions so it can lay flat whether moving backwards or forwards in tunnels. They have very small eyes and are practically blind. Large front paws with thick claws are close to the head and aid the star-nosed mole in excavating tunnels that may run 100 ft. long. Unlike the 38 other mole species they do swim in their hunt for prey. The palms on these forelimbs are turned outward and when swimming it appears they are doing the breast stroke.
Twenty-two fleshy appendages, called rays, surround the nostril just above the mouth. It is believed the star-nose has evolved on this mole because it lives in a moist habitat and unlike those in a dry habitat it does not suffer from “nose burn” resulting from constantly rubbing its nose against the soil. The rays are packed with 100,000 nerve endings in an area the size of a human fingertip. Nerve fibers run through the rays of the star to the brain. This is the most sensitive touch organ in the animal kingdom, six times more sensitive than the human hand. The star is covered with goose-bump like structures called Eimer’s organs. These are found on the noses of all moles, as well as some insectivores like shrews (See PLT’s The Forest of S.T. Shrew). The Eimer’s organ consists of three different sensory receptors – for detecting vibrations, pressure on the skin and texture of objects. They sweep their tentacles back and forth at incredible speeds, identifying prey in less than two-tenths of a second and in just 8 milliseconds determine whether or not it is edible. They eat faster than any other mammal on earth!
Star-nosed moles also have the unique ability to smell underwater. Through videos (see resources below) it was observed that they blow 5-10 air bubbles at fish and invertebrates, and then suck the bubbles back into their snouts for the scents to determine if it is potential prey.
Common in southeastern Canada and eastern United States down to Georgia, their 2-3 year lifespan is spent in muddy burrows and tunnels or swimming to hunt for prey. Females nest in dry vegetation on land and after 45 days give birth to 5-6 babies, called pups, each with a star and ready to find food in about 3 weeks. They feed primarily on earthworms, but also insect larvae and other small soil invertebrates. When they are in the water they eat small fish and crustaceans. In the winter they may be active in water under ice.
Fastest eater, most sensitive sense of touch, unlike any other mole has the ability to swim underwater and unique ability to smell underwater. I would have to agree with Dr. Catania the star-nosed mole is an incredible creature!
Resources
Behold a Neurological Wonder
https://www.nwf.org/Magazines/National-Wildlife/2018/Feb-Mar/Animals/Star-nosed-Mole
The Bizarre Star-Nosed Mole: The World’s Fastest Eater
In the Forest of S.T. Shrew