They include some of the most endangered species due to a reduction in available suitable habitat which leads to fragmentation and increasing isolation of populations. This may occur through intensive land-use such as agriculture and forestry, firewood collection and management practices that reduce deadwood for safety reasons or aesthetic tidiness. There has, however, been a recent increase in interest in this threatened group and there is now an urgent need for conservation effort.
A new special interest group was proposed by Keith Alexander at the 2015 BENHS AGM.
The embryonic aims of the group are: