UK heatwaves and Cave Life

[TheodoreML]

With all the recent heatwaves in the UK, I'm quite interested to see what sort of effect it will have on the abundance and richness of the biodiversity. And if there are any other changes in the cave life.

Has anyone noticed a difference between years? Or just difference caving during this year?

 

[aricooperdavis]

Has there been a noticeable change in cave temperatures as a result of the heatwave? You could do some interesting analysis using data from The British Cave Science Centre to see whether there has been a material change and how significant it has been.

 

[Lankyman]

Would the reduction in water entering a cave have more of an effect? I'd imagine any fish living in an underground stream would have been severely impacted by less food/oxygenated water.

 

[TheodoreML]

Would the reduction in water entering a cave have more of an effect? I'd imagine any fish living in an underground stream would have been severely impacted by less food/oxygenated water.

Good point, since a lot of the nutrition for the different trog/stygobites, troglo/stygophiles are washed into the cave.

 

[aricooperdavis]

There is a dataset for that too - the SWCC's pressure transducer in the OFD streamway.

 

[Cantclimbtom]

Would the reduction in water entering a cave have more of an effect? I'd imagine any fish living in an underground stream would have been severely impacted by less food/oxygenated water.

Although prolonged reduced flow might open up other sections of [underground] river that were previously too fast for fish?

 

[mikem]

Certainly seeing more butterflies sheltering in goatchurch, as it was so dry outside, there's a peacock currently

 

[Pitlamp]

Would the reduction in water entering a cave have more of an effect? I'd imagine any fish living in an underground stream would have been severely impacted by less food/oxygenated water.

Yes; if the water in caves is at a higher temperature it will contain less oxygen. (unlike most solutes gases tend to become less soluble in water as temperature rises.) But one effect related to extremely low water levels I would expect is when sumps unroof, allowing air currents to begin (often very powerful), This will affect the proportions of the various gases that make up the air in the cave and also start to carry in airbourne microbes and spores which aren't normally present (at least not in such high concentrations).

 

[Stuart France]

The big fire over Mynydd Llangattock this summer (a square mile or so) can not have had no effect on Agen Allwedd, the largest LH bat roost in Wales and of international significance. Likewise the upland fires in the Blaenavon area. Some of the Aggy streams are undrinkable now and certain parts of the cave retain a strong smoke odour.

There is nothing left up there except a light brown ash inches deep spread by the slightest wind, disorientated hefted sheep and the occasional shell-shocked walker. No insects, no birds, no vegetation but for the occasional atoll protected by a wide circle of boulders that acted as a local fire break within a swiftly-moving inferno.

The recent rain has put out the fires now, but before that the peat was hot, smoking and igniting in any wind.

Fortunately the Craig-y-Cilau NNR has largely survived and this has an area of trees, some rare, which provide habitat and food sources for the cave bats. There are annual manual bat counts going back 25+ years and I could repeat data logger exercises done in a few years of the past ~20 for comparison with the next year or two.

 

[TheodoreML]

Butterfly or bird?

 

[TheodoreML]

Certainly seeing more butterflies sheltering in goatchurch, as it was so dry outside, there's a peacock currently

Butterfly or bird?

 

[mikem]

Certainly seeing more butterflies sheltering in goatchurch, as it was so dry outside, there's a peacock currently

The bats on mendip don't tend to use caves as much in the summer, they prefer houses or trees for maternity roosts, so we are seeing very few underground (every year). They'll be back as it gets colder

 

[Lankyman]

Butterfly or bird?

I suspect a peacock butterfly?

I've known them to attempt overwintering in the bathroom. Unfortunately it never seemed to be a success for them. If it warmed up (strong sunlight through the window) then it might come out of hibernation and flap around. If Lottie (the cat) didn't get it then its chances outside weren't great either.

 

[TheodoreML]

I suspect a peacock butterfly?
View attachment 27729
I've known them to attempt overwintering in the bathroom. Unfortunately it never seemed to be a success for them. If it warmed up (strong sunlight through the window) then it might come out of hibernation and flap around. If Lottie (the cat) didn't get it then its chances outside weren't great either.

That's beautiful! What a shame with your bathroom butterfly maybe some luck in the future.

 

[bagpuss]

The big fire over Mynydd Llangattock this summer (a square mile or so) can not have had no effect on Agen Allwedd, the largest LH bat roost in Wales and of international significance. Likewise the upland fires in the Blaenavon area. Some of the Aggy streams are undrinkable now and certain parts of the cave retain a strong smoke odour.

There is nothing left up there except a light brown ash inches deep spread by the slightest wind, disorientated hefted sheep and the occasional shell-shocked walker. No insects, no birds, no vegetation but for the occasional atoll protected by a wide circle of boulders that acted as a local fire break within a swiftly-moving inferno.

The recent rain has put out the fires now, but before that the peat was hot, smoking and igniting in any wind.

Fortunately the Craig-y-Cilau NNR has largely survived and this has an area of trees, some rare, which provide habitat and food sources for the cave bats. There are annual manual bat counts going back 25+ years and I could repeat data logger exercises done in a few years of the past ~20 for comparison with the next year or two.

Thank you for the update Stuart, it must have been incredibly saddening to watch it unfold first hand. I'm very glad it's now rained as it was very worrying hoping that other areas weren't also going to get targeted/ accidently set alight.