Spiders and Springtails

The Invisible Spider appears to be persisting well into the winter in 2013, after numbers usually peak in the autumn. This species spins a fine (invisible) web across the trunks of trees. 

Realising that its perfectly acceptable to have a social life on a weekend, I could only afford a couple of hours to the YETI challenges cause this morning. A search through the larch forests besides Suffield Moor near Scarborough produced a selection of woodland birds including great spotted woodpecker, siskin, jay, goldcrest and a pair of mistle thrush rattling across the clear fell. With such heat from the morning sun I wouldn't have been surprised to find an early adder basking on the tumulus, with individuals occasionally seen in warm winter weather. Not surprisingly we will most likely have to wait a couple of months before we start seeing reptiles though. I did however manage to pin down the first spider of the challenge, a little late given how abundant they can be in winter. This was in the form of the invisible spider Drapetisca socialis, it's web as its vernacular name suggests is extremely hard to see as is the spider itself given its only about 4mm long. 

Another group which could be described as invisible are the springtails, these tiny invertebrates are actually hexapods rather than insects. They are amongst our oldest groups of animals, with fossil records dating back 400 million years. I managed to tick off our 3rd species of springtail for the year and perhaps the only one I have the capability of photographing, as most species could fit comfortably onto a pinhead. This is Pogonognathellus longicornis, which has a scientific name far longer than its body. At 6mm this is a giant amongst British springtails and is typically found on trees, especially beech where it can be a key component of the canopy ecosystem. Springtails are key decomposers within most ecosystems and can occur at densities of 100,000 individuals per cubic metre of topsoil, in British woodland. They are also a key food source to species like smooth newt, goldcrest and many of our predatory insects. 

Pogonognathellus longicornis, Britains largest species of springtail. This primitive species has a curious habit of curling up its antenna, like rams horns when disturbed. 

In addition to these two species, some of the autumns fungi are still hanging on, albeit long past their best with common puffball still being recorded today. As well as a couple more invertebrates. Hopefully the other Yeti listers are clocking up good bird and plant lists and are doing better than me for mammals,  I've only managed two species so far (slightly worrying), if we were including tracks and signs I would be able to include badger, red fox, field vole and roe deer too.  

Shiny woodlouse Oniscus asellus a common species within the region,  in damp areas under leaf litter, logs, stones and bark. Interestingly one of few British species capable of coping with acidic soils.  

Jay in flight. A colourful corvid, which is numerous within the woodlands of the Yorkshire coast. The autumn of 2012 saw an influx of continental birds move into the region, due to the acorn crop in Europe failing. 

Common puffball, looking past its shelf-life. This interesting group of fungi release spores through an opening on the upper surface.