Instead of writing about domestic animals this week, I thought it might be interesting to look at something weird and wonderful and found - amongst quite a few other oddities – the Star-Nosed Mole (Condylura cristata).
Its nose is so weird, that at first glance it appears that it is struggling to eat a pink flower head! It reminds me of one of those monster digging machines - on a much smaller scale of course - for creating new tunnels underground for railways. It isn’t a native of Portugal, but is found in eastern North America – and although not rare, it is rarely seen, as it spends the best part of its time underground. They are such loners that three to five moles per acre is considered a lot, according to Internet Center for Wildlife Damage Management.
This funny little creature measures only about 27cm in length, and weighs in at 49g, about the size of a hamster, and although it does have eyes, is virtually blind. But its most startling feature is its nose, which isn’t actually for digging but is a touch organ, with more than 25,000 tiny sensory receptors known as Eimer’s organs, with which this little mole feels its way around. Eimer's organs were first described in 1871 by German zoologist Theodor Eimer. Although other mole species also possess Eimer's organs, they are not as specialised or numerous as in the star-nosed mole. Because it is functionally blind, the snout was suspected to be used to detect electrical activity in prey animals, though this hasn’t been proven.
The 22 ‘arms’ or ‘feelers’ of the extremely sensitive star-like organ on its snout contain more than 100,000 nerve fibres -- five times the number of ‘touch’ fibres in the human hand, all packed into a space smaller than your fingertip, and those studying it saying it could provide insights that could improve our understanding of the human sense of touch.
At the centre of its strange snout is a small area called the ‘touch fovea’ that the mole uses for all of its most detailed explorations. Although their eyes are pretty much useless, the touch fovea is neurologically organised in a way that is similar to a highly developed visual system. As the mole moves through its environment, it constantly shifts the star to reposition the sensitive fovea on areas of interest, just as we would shift our eyes while reading the words printed on a page. This weird snout is the most sensitive known touch organ in any mammal.
Its diet consists of earthworms, aquatic insects, snails, crayfish, small amphibians and fish, and a fascinating fact is that they can identify and eat their prey in two-tenths of a second – faster than any other mammal on earth – taking only 8 milliseconds to decide if it's edible or not.
They are just as happy underwater as underground and are able to use their shovel-like front limbs to tunnel through soggy, marsh-like areas, often diving and swimming for food. Star-nosed moles have been shown to blow bubbles into the water and then re-inhale them through the nose in order to sniff for prey, making them one of only two mammals known to smell underwater – the other being a water shrew.
It is active both day and night, and has become adept at being able to maintain a high body temperature in freezing conditions, called thermoregulation, and is well able to endure tunnelling through snow, or swimming in ice-covered streams.
Although not much is known about this little weirdo, they apparently mate in the late winter or early spring, and a litter will contain four or five babies measuring around 5cm each, with the mother able to have a second litter if the first litter is unsuccessful for whatever reason. They are born hairless, with their eyes, ears and ‘star’ all sealed, all only opening and becoming useful after about 2 weeks. They are independent after around a month, are mature at 10 months, and have a lifespan of up to 3 years.
I guess with a nose like this, they can truly be said to be getting a feeling for food!