Beavers are steadily returning back to the UK, and that’s absolutely fantastic. The more the merrier. But over the weekend I visited a site that provides evidence of their historic presence in Yorkshire.
Mr Moo’s is a popular ice cream parlour on the Holderness coast, just near Skipsea, with a café and a farm walk that leads down to the coast. But you have to wonder how many people as they follow this path, walking off their massive sundaes, realise they are tramping along the top of an ancient mere?
A mere is a broad, shallow lake and there are plenty to be found still, for instance Hornsea Mere or Martin Mere. But in this case, we are talking about a mere that hasn’t existed for more than 4000 years.
Withow Gap is a Site of Special Scientific Interest (SSSI) because it has a quite remarkable feature in the cliffs. Scramble down to the beach, look back, and the bed and accumulated sediments of this ancient lake are laid out in front of you.
The lake probably formed around 12,000 years ago, just at the end of the last glacial period as ice retreated. Dating of the sediments suggests the oldest are around 10,000 years, and the most recent about 4,500 years. The sediments are pretty much peat at this point, although I’ve also recently learned the word ‘gytjja’ which describes peat decaying into mud, which is also present here.
Being able to see this all so clearly is really special, and for a geologist like me, with a particular interest in this sort of thing, it’s very exciting. But it gets better. Within the sediments here are lots of timbers.
Towards the bottom of the sequence they are basically fossilised, but up towards the top they are sub-fossil, meaning much of the organic material remains. We can as a result learn what sort of trees surrounded this mere, and it’s mainly alder, with a bit of ash, willow, and hazel. Plenty of other plant remains were in there too.
Also among the timbers are mollusc remains, remains of hazelnuts, other plant material, beetle remains, and…beaver hair. Because at this end of the mere it turns out, there was an ancient beaver dam. In fact, some of the timbers show evidence of having been ‘worked’ by the beavers (i.e. gnawed).
Beavers became extinct in the UK around 400-500 years ago, though they have now been the subject of some partial reintroductions. But it’s great to see such strong physical evidence of their Yorkshire heritage. Hopefully we have them back in numbers in the county before too long.
There are some reports suggesting human-made arrowheads were found in the dam too, but I’m yet to find a substantiated source for this. There are a few references though to human utilisation of worked wood, bone barbed points, and red deer butchery, so it seems humans were certainly active around the mere. East Yorkshire is well known to be a hotspot of post-glacial human activity so this isn’t a surprise.
For anyone considering visiting, some advice. Firstly, it’s a wet and muddy track down by a stream to get there. Secondly, the cliff is one of the fastest eroding in the country. And thirdly, make sure you check the tides as you don’t really want it pressing up behind you.
Final note – this is a SSSI and you should not be poking about in it, trying to remove anything. It’s dangerous and destructive.
Also, thanks to Jon Traill and Andrew Gibson of Yorkshire Wildlife Trust who told me about this site.