A lot of my time recently has been taken up by preparation for my masters, which focuses on the importance of otters in chalk stream rivers. So a couple of weeks ago I decided to take part in one of the Yorkshire Wildlife Trust otter walks. This experience is all about learning about the importance and conservation of otters, but also gives the unique experience of seeing the change in wildlife as the evening sets in. This is usually reserved for members only.
Unfortunately, we didn’t actually see any otters this time, which considering that otter ranges can span from 5-10 miles, isn’t completely surprising. However as the central point of an expanding protected area, Tophill Low still displays an incredible range of British wildlife. And with each event only having around 10 places, it provided a relaxing and enjoyable evening.
Beginning with a talk about the otters themselves, going into detail about some of the projects the University of Hull has run on the site. In particular they discussed the differences in diet between the Eurasian otter, and the invasive American mink. Whilst otter have a predominantly invertebrate based diet (which may be surprising, as many believe they focus mainly on fish), the mink heavily predates on small mammals. This has caused a huge loss of water vole, which are critical to nutrient cycles and resource preservation.
One fact that was particularly interesting to me is that otters will only predate in the water. On land they apparently appear to ignore predation opportunity. This is something that lends itself nicely to my upcoming master’s project (which I will hopefully have finalised soon!).
After, we moved to one of the observation boxes overlooking the river and a neighbouring bog. Two of the most regular species seen at the reserve in the evening is red foxes and roe deer. This particular evening however, it was all about the birds. A whole chorus of species could be heard the whole evening, with woodpeckers drumming in the trees, cuckoo's calling and Cetti's warblers singing. Cetti's warblers were a species I knew very little about, but was interested to hear that they are one of the many species being affected by climate change. As the conditions warm, individuals are forced to travel further north to remain in the optimal conditions. This is how then ended up in Hull!
One of the other most vocal species was the heron, which would fly above in a pair regularly following calls from their young. These calls were not what I would have expected. Instead of a bird like squawk, they sounded almost like a dog barking. Alternatively, my favourite species we saw was the Barn Owl, which flew up and down the distant bank. This is another species affected by the presence of the mink. Feeding on water voles, a decline of their numbers forces search for alternative sources. In some cases, where barn owls become desperate (also in may other bird species) they will kill or eat offspring they can no longer care for.
I am hoping on one of my return visits I will actually see an otter, and that with my masters I will learn a lot more about them. Right now I am excited to start my project and see what happens!
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