Bed knobs and Broom ticks

Posted by Graeme Lyons , Sunday 16 May 2021 12:28

I have had a bit of a break from blogging recently. Not natural history though, I am already 36 field days into my field season, with over a quarter of the work complete for the year already. One of the most exciting projects I am working on this year is the #WilderBlean invertebrate baseline survey. Kent Wildlife Trust are going to put bison into part of Blean Woods, well West Blean Woods in fact. It's all being monitored heavily before hand, which is great. This includes a solid baseline, with controls and proxy grazers. So using my methodology for monitoring invertebrates on rewilding projects, but scaled up to take in the three different treatments, I will be heading to Blean monthly between April and September. You can read more about the project here.

It turns out Blean is one of the best woods for spiders in the south east, well the UK even, but this bit of Blean hasn't ever been as well recorded as say the RSPB part or East Blean Woods. So, after the second round of visits, I am up to 105 species of spider already, 15 of these have status (that's really good for a wood!) and quite a few of these are Blean specialists. One such species though I was NEVER expecting to find. Walckenaeria mitrata has only ever been recorded from two sites on the western most part of Blean. Have a look at the SRS page for the species here. Here are some more shots, a difficult spider to photograph well but as with most Walckenaeria, the head in the male is produced up into a bizarre 'bed knob' structure (with a pair of eyes on), held back at a jaunty angle. Here are some more shots.

Only nine specimens have been recorded, in 1967 & 1971 on the RSPB Reserve and then again in 2004 at Church Wood. So when I found a male in the suction sampler, I was rather excited, as this is only the third site for this nationally rare/vulnerable spider, ALL in Blean Woods. Interestingly, all the old records were from Sweet Chestnut coppice but this one was from a...conifer plantation!

Which just shows it's probably not as picky as we think. Or that it's at very low densities. Or both. It was strange that I looked at so many other compartments that were nicer habitat than this. It's certainly one of the least interesting of the 24 compartments I am looking at.

I wasn't going to year list spiders this year but it sort of happened. I couldn't help looking in the database and seeing what I have recorded so far. I was desk bound until 30th March though. That hasn't stopped me making over 1900 spider records in six weeks though, and 205 species already. I've had an incredible nine species new this year too, five of which are from Blean.

The leaf litter there is exceptional, sometimes I will find up to four nationally scarce species from sieving a couple of handfuls of litter. New to me (and so far the most widespread of all the spiders with conservation status in the wood - occurring in 15/24 samples) is Phrurolithus minimus. It's incredibly distinctive, appearing very red in the field. It's quite unlike the much commoner and more widespread Phrurolithus festivus.

Scotina celans is also extremely common throughout the litter, recorded in half the plots so far and very many adult females still present in April and May.

Entirely new for the whole of Blean is Euryopis flavomaculata. I have now recorded this in 7/24 plots and it has been recorded in every habitat type except high forest. It's a distinctive spider, even as an immature, and is readily collected by pitfalls. So I think this is most likely a recent colonist rather than something that was overlooked. It could be that it's only found on this bit of woodland and not East Blean and the RSPB reserve but this seems unlikely. I can't see that it has been missed. Also new to Blean in one very open compartment, is the ever expanding Sibianor aurocinctus.

Also common in the litter is Halpodrassus silvestris. So far found in 7/24 compartments.

Another one new for me is the tiny Tapinocyba insecta. So far, only recorded from two plots. A tiny spider of the the leaf litter. I have not seen this anywhere else.

The recent addition to our fauna, Nigma flavescens, was recorded at three sites in early May. I expect I will pick this up more when leaf burst actually completes. It's really taking it's time this year!

It's certainly not all spiders there. This Na Tychius parallelus, a large and stripy Tychius that feeds on Broom, is the only non-Dungeness Kent record! A new one for me. It appears to be spreading though, as the very next day, Scotty had it in Surrey. A rubbish photo but you get the idea.

With lots more visits this year, I can't wait to see what else I will find! Could it involve Pistius truncatus? Now THAT would be something!

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