In search of the Duddon Great White …Whale, shark? The setting for this story of a wildlife in the English countryside, which does mean this is unlikely. That should help calm anyone with a nervous disposition. I will confess to our quarry not featuring on anyone’s ‘top ten most dangerous animals to humans list.’ My temptation is to force you read our story to the end and then let you know what we are looking for. However, it drives my partner mad when I do that.
Our quarry is the Greater White Toothed Shrew!That’s right, a Shrew. Why? You ask, what is so special about this particular Shrew and what could possibly make this an interesting story.
Well, the first question has an easy answer, The Greater White Toothed Shrew. Only an ecologist could have dreamt up such a snappy and memorable name for such a tiny creature. Anyway, it turns out that these particular shrews don’t belong in the Duddon or anywhere near it, always assuming we have correctly identified them. They are regarded as an invasive non-native species. They are native to mainland Europe but were reported to have arrived in Ireland in 2008. Their presence has only been confirmed in two places in England. In 2021 they were recorded in Sunderland, their first confirmed appearance in England. Their presence was originally discovered by Jeff, a cat belonging to a Mammal Society supporter. The owner posted a picture of an unknown shrew caught by Jeff on Facebook where it was identified by an ecologist, Ian Bond. Subsequently, there have been confirmed animals present in County Durham, and Nottinghamshire.
This particular shrew, as with many non-native species brings the potential for problems for our native species. It appears that in Ireland they have out competed the native Pygmy Shrew resulting in a population collapse. Whilst there is limited evidence of their impact in England, it seems prudent to monitor our invaders whilst we begin to fully understand the consequences of their arrival.
And the big question I hear you asking now is ‘How do you know?’ Well… it started with an acoustic monitor. The use of this technology that allows us, or specifically Matt, to collect recordings of wildlife and in particular bats. Thus far we have accumulated around 700mb of data or 30,000 individual recordings. This is a large amount of data to process. In order to get through the workload, the BTO Pipeline software is used to analyse it. On the website if you go to the Nature page you can find much more detail on the use of these recordings to study the local bat population, but I digress.
Returning to our story. In amongst the species that the system identified was a recording of our suspected Greater White Toothed Shrew. This was a little unexpected, given the expected range of the species. However, there were a number of similar recordings identified, which demonstrates a consistency within the system even if it doesn’t provide proof that the shrew is present. This presents us with a bit of an issue, in that the system is not 100% accurate. Therefore, we really need to confirm the presence of our quarry by another means. For a variety of reasons, the easiest way to do this is through the collection, dissection, and analysis of Barn Owl pellets. The analysis is undertaken as part of the ‘Searching for Shrews’ project, undertaken by the Mammal Society and Barn Owl Trust.
As I compile my story we have received approximately 150 Barn Owl pellets, which have all been dissected and studied. To date we have identified skulls from Common, Water and Pygmy shrews. The good news is that so far none are from our illusive, invasive non native Greater White Toothed Shrews. The most commonly identified skulls were Field Voles.
How can you help? Please, don’t be shy we need more samples of pellets from Barn Owls.
