I am an amateur naturalist trying to identify everything living in my garden.
Typical isn't it, you wait thirty-seven blog postings for a garden mammal, and then two come along at once. After my triumph of badger photography, ladies and gentlemen I present photo 1: the European mole (Talpa europeae). As may be obvious from the photo, though mole hills have periodically appeared in my garden for a number of years, I (in common with most people) have never actually seen a live example of this elusive little creature that lives almost its entire life underground hunting for worms and insects.
To learn something about moles I have been reading The Mole (Kenneth Mellane, Collins New Naturalist). Having been written over thirty years ago (1971) I expected the information in the book to have dated somewhat, and indeed the extensive treatment of the methods employed by mole exterminators and the suggested method of tracking moles by fitting rings of radioactive Cobalt-60 (!) to their tails might less readily find their way into a textbook aimed at amateur naturalists today. Interestingly however, though my searches have been far from exhaustive, turning to the internet I've yet to come across any very detailed site describing the ecology of this most secretive of British mammals (can anyone point me to one?).
From Dr Mellane's book I learn that the average male mole comes in at 14.3cm, 110g with females marginally smaller. European moles are not entirely blind, though their eyes are tiny and mostly hidden by their fur (which, I learn, has no particular 'lie' i.e. it responds equally to being stroked in either direction, unlike the fur of, say, cats as pet owners will know). Moles have a highly developed sense of touch - their snout being covered with thousands of tiny, sensitive 'pimples' known as Eimer's organs. I have to confess at first reading I was highly sceptical of the suggestion in the book that:
"it is tempting to think that moles have other and more unusual senses...[finding] its way in its burrows by some sort of "radar" using some radiation we do not experience"
Subsequently however I've come across the NSF Digimorph site, where I read:
"some authors have suggested that the nose of Talpa may be sensitive to electrical or magnetic signals"
Can anyone comment more concretely on whether moles do or don't have senses of this nature?
Apart from a short time spent mating, moles are, as Dr Mellane puts it:
"aggressive, quarrelsome and solitary"
The Arkive site explains that female moles are the only mammals to contain vestigial testes ('Ovotestes'). These produce large amounts of testosterone and it seems this may account for the tendency of female moles to be just as aggressively territorial as males.
Gestation in moles lasts four weeks. Birth is in late April in the South of England, and the young start to leave the nest (one of the few times they may travel above ground) after about a month to establish territories of their own.
Of course, the most widely recognised feature of moles is their hills. They've certainly made quite a mess of my normally immaculate (hem, hem) lawn as photo 2 shows (does anyone know of a humane way of getting rid of moles incidentally?). Moles are extremely skillful tunnelers: burrows may be on multiple levels and in experiments in which whole sections of burrows where removed, Dr Mellane found that they will even pack together balls of clay to reconstruct a tunnel arch. Moles work and sleep in 3 hour shifts (3 awake, 3 asleep etc.) and Dr Mellane likens the effort a mole makes in pushing up the soil in a molehill to a human miner moving 12 tons of soil in an hour.
Occasionally moles may construct giant mole-hills known as 'fortresses' comprising hundreds of kilos of soil. The suggestion seems to be that fortresses are built to raise a brood chamber above the water-level in flood-prone areas. Dr Mellane disputes this however, and asserts that their real purpose remains a mystery.
Finally, I warned last time of the perils of listening to badgers! The lesson from King William III of England's death is that moles can be just as bad for your health. In 1702, William was thrown from his horse when it tripped over a mole hill. William broke his collarbone and subsequently died from complications. I shall be watching where I tread when I next time mow the lawn!