The undocumented Irish wildlife the white-toothed shrew
Irish mammal species are few in number compared to the mainland European total or even the British total. So you'd think that we'd know their breed, seed and generation or at least how many of them we have and their distribution around the country. So imagine the amazement of the two post graduate students from UCC and Queen's University who were conducting run of the mill examinations of barn owl pellets last autumn, when they discovered undigested skulls which didn't match any small mammal known to exist in Ireland. And not just in one or two, these skulls were in the undigested pellets of barn owls and indeed kestrels too from 15 different locations in Tipperary and Limerick.
Close scrutiny and measurements confirmed their identification – they were the skulls of the greater white-toothed shrew no less, a species who until that that moment had been recorded no nearer to Ireland than the Channel Islands. It doesn't occur in Great Britain at all. Had these barn owls and kestrels flown here directly from their holidays in Guernsey or Alderney with their last meal still undigested in their crops? Hardly – as these are sedentary species – not known for having a propensity to travel. They must have caught them here. Could the scientists equal this achievement?
They could. They got the live traps out put them in every possible location and caught seven live greater white-toothed shrews in Tipperary. The species is definitely established here in the wild and looking after itself.
Is this a good thing or a bad thing? New species that come in on an established ecosystem cannot fail to have an effect if they manage to become established. We already have a shrew species – the stowaway that came with the Mesolithic people from Andorra eight thousand years ago – the pygmy shrew – he of the red teeth due to iron absorption. This tiny shrew has become established the length and breadth of the country. His larger relation – although not by much , they are both smaller than fieldmice- may outcompete him where their ranges overlap. They are both carnivores and dine on beetles, woodlice, spiders and flies.
On the other hand as had already been established, they feature in the diet of barn owls who are in small numbers in this country because of a lack of prey species to feed on. Here is another tasty item for the menu which may well make a substantial difference.
And where did this species come from, and when and how? What part of Ireland did it arrive in and how many counties is it in now? Sure there is enough here for a whole conference!