Posted by Graeme Lyons , Sunday, 19 January 2014 13:16
I helped Sussex Bat Group to count the hibernating bats in the abandoned tunnels and mines in West Sussex yesterday, my main motivation being to get access to our Marehill Quarry site as I haven't been in there for several years. Bat numbers were low due to wet and mild conditions but we did see Natterer's and Daubenton's Bats and I'm feeling much more confident at identifying those two now. There were no rare bats this time.
As ever though, it was the invertebrates that got me excited! In the West Dean tunnel (above), we recorded the usual Herald moths, mostly around the cave entrance along with a couple of Peacock butterflies. The only other moth we saw deep in the cave was a single Tissue (quite a scarce moth in Sussex). Spiders were poor here restricted to Metellina merianae, we didn't see any of the larger Meta species. Further into the tunnel we saw a single Eristalis tenax, a rove beetle that turned out to be new to me, Quedius mesomelinus. At about 200 m in which is approximately the half way mark and about as far as you can get from the light, we recorded Cellar Snail Oxychilus cellarius (new to me!) and Rosy Woodlouse. The only other species we saw was Oniscus asellus.
At Marehill Quarry, you are never that far from the light so there tend to be more invertebrates (last time I was there I recorded a Bloxworth Snout). By far the most frequent species being a heleomyzid fly, that at first I thought was Scoliocentra villosa but now I'm not so sure. Heralds were again present in numbers also accompanied by a single Tissue. A cluster of Eristalis tenax was present at the entrance as was a single Armadallidium vulgare. The spiders though were much more interesting. There were lots more Metellina merianae as well as a male Micrargus rufus (new to me), a stonking male Amaurobius ferox with white palps and best of all a Comb-footed Cellar Spider Nesticus cellulanus (photo above) which I have never seen before. This is quite a local species and it doesn't look like there are that many records of it in Sussex. So I got four new species and end the day on 4765. I'm already 47 up in 2014 including 20 beetles!