The second-most interesting thing of the seed-exchange weekend was the rather unfortunate encounter with this creature. My mom and I had spent a half hour or so at the mudpuppy event, then, because the night was still young and we weren’t too far, decided to drop by my sister’s place to meet her new puppy, which she’d brought home only the day before.
She lives on a horse farm on a rural sideroad, surrounded by many acres of both natural and cultivated habitats. As we were pulling up her long driveway, I noticed a dark shape waddling in circles in one of the tire tracks. Unfortunately, the driveway was icy and slippery, and while we might have stopped the car in time in dry conditions, on the ice the wheels locked and it slid. I hopped out to check on the animal, but we hadn’t been able to avoid him.
Making the best of sad circumstances, however, I grabbed my camera from the car and took a couple dozen shots of the creature. The dark bundle of fur turned out to be a Star-nosed Mole, Condylura cristata. Despite the poor thing’s untimely demise, I was pretty excited to actually see one up close and be able to get a good look at it. I’d only ever seen a mole once before, and it was a fleeting glimpse insufficient to identify the animal to species. I’d never been able to check it out in detail.
The mole is, of course, named for the wildly unique appendage found at the end of its snout. There are 22 fleshy “fingers”, 11 on each side of the nose. The mole is effectively blind, visually, and the star acts as the mole’s eyes. Over its surface are spread some 25,000 mechanoreceptors that are exceptionally sensitive to touch (consider that in our entire hand we have about 17,000 similar receptors).
These receptors are linked directly to the brain, and signals from the star are received and interpreted at lightning speed. It takes the mole only about 25 milliseconds (1/40th of a second) to detect a potential food item and decide if it’s good to eat. Consider that it takes us about 600 milliseconds (3/5ths of a second) to detect something jumping out on the road in front of our car and stomp on the brake. Nearly half of the mole’s brain is dedicated to interpreting the signals from its sensory star. Some scientists have also hypothesized that these receptors might also be able to detect the natural electrical impulses that living creatures produce, though there is currently little data to back this up.
(These facts primarily taken from, and more info on the mole’s fascinating nervous system arrangement available at, this excellent ScienceBlogs post.)
Star-nosed Moles are active all year. They’re excellent swimmers and spend a lot of time in or near water, especially during the winter months when the ground’s too hard to do any foraging in the soil. Because of their amazing nose, they’re the only known creature able to smell underwater. They accomplish this by blowing out tiny bubbles then re-inhaling them, detecting the scents that the bubbles pick up from the water. They have long, relatively thick tails that they use to store fat during the leaner winter months.
They’re also pretty darn good diggers, too, as expected with paws like that. The oversized forelimbs are broader than long and angled sideways, equipped with massive claws for tearing through dirt. They function as big scoops, allowing the mole to move large quantities of earth quickly. They can and do make molehills, though these are more typically the product of its land-dwelling cousin species, the Eastern Mole, Scalopus aquaticus (the scientific name is clearly a misnomer; the original specimen from which the species was named had been found dead in water).
I spent much longer than intended reading up on the Star-nosed Mole – what a fascinating species! A shame about this unfortunate individual, but at least you and I got to benefit from it.