Talpa europaea
As usual I did not go out to see moles, and to be fair I didn’t actually see a mole, I saw plenty of mole hills, but no moles. What I went out to see was a Roman fort just south of Norwich at Caistor St Edmunds (Roman name Venta Icenorum, literally market place of the Iceni) However, the earthworks the moles had shovelled up were good enough for me to blog about the animals that made the hills.
The European mole is in found over most of Europe, except places with severe winters like Scandinavia or really hot summers like Italy, Spain and Greece, see map below.
Notice on the distribution map, no moles in Ireland? For the same reason as there are no snakes, Ireland's climate should be perfect for moles, grass snakes and adders, however at the end of the last glaciation, as the ice sheets retreated and sea levels rose - about 14,000-10,000 years ago - there was a land bridge between Europe, Britain and Ireland. Slowly as the climate warmed both flora and fauna migrated from Europe to the newly exposed lands to the west. But before many could make it across the land bridge, the sea rose.
The sea continued to rise as it warmed the land bridge to Ireland was lost first, many species just didn't get to colonise Britain or Ireland before the sea covered the two land bridges. Snakes and moles got as far as Britain, but were too late to get to Ireland, Rabbits incidentally didn't make it to Britain or Ireland either, they were brought over by the Romans (not by the Normans as I was taught at school).
Which Segway's back nicely into the Venta Icenorum, while I was wandering about the huge Roman enclosure, surrounded by a high bank and stone wall (mostly now gone, the stones were robbed out after the romans left) I noticed the hundreds of mole hills amongst the sheep grazing away.
It is illegal to dig anywhere on this protected archaeological site, but....no one has told the moles that....hence anything the moles dig up is a 'surface find' useless for archaeological dating and a neat trinket to pick up and have a look at (I never take these finds home I chuck them back on the mole hills) I have previously found an amber bead, a hob nail from a roman boot, masses of tile and pot chards. Obviously if I found something other than Roman junk I would report it.
Something you don't expect to see is Oyster shell, the fort is 30 miles from the sea? And there is masses of Oyster shell in the mole hills, even more in the mole hills outside the walls?
Ostrea edulis British Oysters live in the sea or brackish water, yet here they are 30 inland in their thousands?
Apparently the Romans loved Oysters, so much so, they were brought in by river from the sea by the basket load - the river is still there at the bottom of the fort. Once eaten, some romans just tossed the shells over their shoulder on the ground and walked on. Most were collected up and dumped outside the walls, hence the larger quantities of shell in the outside mole hills. The cool thing is should you visit Venta Icenorum and you pick up a piece of oyster shell from a mole hill you will be probably the first person to touch that for nearly 2000 years, the last person to touch before you was the Roman who had just eaten it.
In my hand a chard of Roman roof tile and a piece of Roman oyster shell.
Below is me trying to recreate the 'Time Team' logo (badly) with Ostrea edulis shell.
Standing inside the site, the roman wall on the left is the outside wall, below are the mole hills that cover the sheep field inside the fort.
Back to moles, for a few facts, moles are not closely related to mice or rats, they are in a distinct order of mammals called Eulipotyphla which includes Hedgehogs, desmans and shrews.
Moles are not blind and deaf, they do have eyes though there eyesight is poor, and they have ears but more of a blunt ridge than an ear like a mouse.
A mole can tell the difference between light and dark, but beyond that no one is certain about their vision. Hearing is another grey area, it is thought they can defect low frequencies and their anatomy suggests that their hearing apparatus is used more for detecting balance and depth underground than 'hearing' as humans would percieve hearing.
Because they spend almost the entirety of their lives burrowing underground in total darkness, knowing direction, gradients, depths and pressure would be of great value, using its 'hearing' in a different way to us is much more useful to a mole.
We also have the capability to feel pressure in our ears too. If we have our eyes closed in a car, trying to dose off, we can tell if we have driven up a 400m hill, your ears pop. I think moles have this ability from what I have read about them, but developed to a highly sophisticated level (wildlife online 2020)
They live off a diet of predominantly earthworms, but also grubs and larvae, centipedes other insects and even shrews if they find them. They give birth to 2 -7 molettes (I just made that word up, its actually a pup) in spring after gestation of 4-5 weeks.
I won't bore you with they have big forelimbs, are great diggers etc, but I will leave you with the interesting fact that moles have a toxin in their mouths that paralizes worms and other insect prey.
Wildlife online (2020) European mole. Available at: https://www.wildlifeonline.me.uk/animals/species/european-mole (Accessed on: 05/03/2020)
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