Cicurina cicur at Fordon Banks SSSI

 

Cicurina cicur Fordon Chalk Banks SSSI

As a regular visitor up to Fordon Chalk Banks SSSI (likely to be a regular feature on this Blog) a site only around 6 miles from my house, it is always lovely to find another new species for my site list. 

Cicurina cicur is an attractive small, peach coloured, spider which is recognised as Nationally Scarce (Harvey et al., in press), this species is also included on the recently published spider Amber List. This includes species which remain widespread but have undergone substantial population declines. These Amber Listed species are likely to be updated with an IUCN Near Threatened Status if population declines fail to reverse.

It would be wrong to suggest species like this are not declining, however a lack of recording somewhat complicates the overall picture. Cicurina cicur is a species locally which appears to be restricted to calcareous grasslands, in my own experience it seems to prefer chalk, but I suspect the limestone grasslands along the Vale of Pickering may also contain populations, an area I will soon be searching. Indeed Smith (1989) notes all recent Yorkshire records refer to those parts of the county where chalk or magnesian limestone is the basic geological formation. The species was recorded within the area between 1980-1991 on the Spider and Harvestman Recording Scheme distribution map (accessed from website November2019), with no subsequent records. Further south in Britain, whilst still scattered, the species appears to be less habitat specific, even occurring on base rich clays and eutrophic habitats.

I found 12 individuals all within a specific habitat type in mid-November on Fordon Chalk Banks SSSI, with the majority being females. All were found beneath windfall Ash Fraxinus excelsior and Hawthorn Crataegus monogyna logs in both open scrub edge and enclosed hawthorn scrub habitats. A basic habitat characteristic was a preference for damp situations, with relatively high soil moisture at the bases of slopes. Non were recorded from beneath rocks or amongst scree on dryer mid and upper parts of the banks inside or outside of scrub. Other spiders were relatively scarce during searches other than the ever present Amaurobius fenestralis, with which Cicurina shared several logs and appeared to co-exist.

Refs.

Smith, C.J. 1989. Cicurina cicur (Fabricius) in Yorkshire. Newsl. Br. arachnol. Soc. 54: 5.