Friday, July 30, 2004
Biodiversity Corner: Star-nosed Mole
Name: The star-nosed mole is Condylura cristata, a member of the order Insectivora. The genus name, Condylura, means knuckle-tail because the tail of a dried specimen has a knotty look. The species epithet, cristata, means crested and is a reference to the strange nose with its 22 appendages.
When and where seen: Found by Terry Ritz on July 4, on Church Street, near the fire pond. Star-nosed moles like low wet habitats and are often found near ponds, streams, and marshes. They are excellent swimmers and since they don't hibernate they can sometimes be seen in winter swimming beneath the ice on ponds.
Distinguishing characteristics: There is no animal you could mistake for a star-nosed mole. It looks like the result of a genetic engineering experiment with a rodent and a sea anemone. The tip of the nose has 22 little fleshy tentacles arranged in a star-like formation around the circumference of the snout. The tentacles have excellent mobility and are densely packed with nerve receptors and blood vessels. This unique nose is able to detect touch, vibration, pressure changes, chemicals, and possibly temperature fluctuations. It is thought to be of most use when foraging for food in the soft muck at the bottom of ponds. When the mole is digging, it protects its sensitive snout by folding the tentacles, but when it is in the water, the tentacles are fully expanded and highly active. Adult star-nosed moles are 6.5 to 9 inches long from tip of nose to tip of tail. This one was 8 inches long; 4.5 inches for the body and another 3.5 inches of tail.
Digging: The whole mole is adapted for digging and for life underground, from the fur to the tiny eyes, tiny ears, large shoulder blades, deeply ridged breastbone, strong chest muscles and massive paddle-like fore-limbs with sharp claws. Mole fur is dark and velvety and has no grain — you can rub it in any direction and it will still look and feel sleek. This allows the mole to go backwards or forwards in a tight space without undue friction. Moles use a unique lateral digging technique. The star-nosed mole can tunnel at the rate of 7 or 8 feet per hour — not as fast as the eastern mole which can dig at almost 13 feet per hour. Two types of tunnels are dug; shallow ones near the surface for foraging, and deeper ones up to 2 or 3 feet down for nesting and over-wintering. Foraging tunnels are regularly patrolled for prey that has crawled or fallen into them.
Friends and relatives: Two other species of moles are found in New England. The most widespread is the Eastern mole, Scalopus aquaticus, which despite its name, is less aquatic than the star-nosed. It has a short naked tail — about half the length of the star-nosed mole's. Our smallest mole is the Hairy-tailed mole, Parascalops breweri, which has a short tail covered with stiff black hair.
Favorite food: Earthworms and insect larvae. The star-nosed mole also eats aquatic insects, snails, leeches and even small fish. It can't be too picky because it has a very large appetite, with a daily intake equivalent to one third or more of its body weight.
Favorite song: "Getting to nose you, getting to nose all about you."
Words for the week: 1) benthic — an adjective meaning bottom-dwelling. Could be used to describe star-nosed mole prey or certain political muck rakers. 2) fossorial — an adjective meaning adapted for or used in burrowing or digging. Could be used to describe the front limbs of moles or the mind set of certain political muck rakers.
References: Adrian Forsyth, Mammals of North America — Temperate and Arctic Regions; Alfred J. Godin, Wild Mammals of New England.
Submissions for the Biodiversity Corner are encouraged from everyone. Send a photo, a note about a sighting, or the whole column to Kay Fairweather at 392 School St, Carlisle MA 01741 or to email@example.com.
© 2004 The Carlisle Mosquito