From Wildlife Extra:
July 2012. Staff from the British Arachnological Society have discovered one the UK’s rarest spiders, the Midas tree-weaver (Midia midas) at the Woodland Trust’s Hainault Forest in Essex. A female specimen was found in one of 20 traps which were placed amongst the 6,000 hornbeam pollards found in the ancient woodland.
A money spider, associated with ancient trees, the Midas tree-weaver is listed as nationally endangered and is identified as a Priority Species for conservation action under the UK Biodiversity Action Plan (UKBAP). In the UK, the spider has only ever been recorded in five locations, one of which is Hainault Forest – but the last known recording of the spider on site was over 30 years ago.
Geoff Sinclair, Woodland Trust Site Manager, said: “Ancient woodland is one of the most precious habitats we have and the fact that a Midas tree-weaver has been recorded in Hainault Forest highlights the importance of ancient trees and woods as a wildlife habitat. We must do all we can to protect them to ensure the survival of such creatures.”
The surveying was carried out by sorting litter, birds nests and squirrel dreys from ancient trees and placing aerial pitfall traps in the crowns of trees.
Tony Russell-Smith from the British Arachnological Society added: “Despite the heavy rainfall in May and June which flooded many traps, the fact that we have found the tree-weaver again is a great result and confirms its continuing survival at this site, the only one so far recorded in the whole of the UK this year.”
The work forms part of a wider survey to establish the distribution and status of Midia midas in different regions of Britain. It is hoped to use the information obtained to clarify the need for future conservation work for this species and to help define the scope of such work.
The midas tree weaver, Midia midas is one of Britain’s rarest spiders. It is equally rare throughout its range in Western Europe, where it has been recorded from Denmark, France, the Czech Republic, Poland, Romania and Spain, either from single or a very few individuals. In the UK, it has been recorded from just five localities, Sherwood Forest, Notts. (Crocker, 1979), Donington Park, Leics. (Crocker & Daws, 1996), Epping Forest, Essex (Russell-Smith, 2002), Hainault Forest (Essex) and Windsor Forest (Berks), where it is always associated with ancient trees, either in forest or ancient wood pasture settings. The reasons for its close association with ancient trees are still unclear but its extreme rarity almost certainly results from both habitat loss and decline in woodland management practices such as pollarding.