09 Aug 2011 The thorny question of bats in trees
Locating bat roosts in trees is challenging. If you are very lucky “chittering” may be heard from a tree hole at sunset just before bats emerge, however, trees roosts are typically difficult to identify and cannot be reliably assessed from checks at ground level alone.
An aerial bat roost inspection, a technique which involves ascending a tree using ropes, allows for detailed checks of cavities on a tree for any evidence of bat activity to be carried out using torches, endoscopes and other specialised equipment. Often features which look potentially suitable for roosts when viewed from the ground can be ruled out on close inspection. Because it is often more definitive, an aerial inspection can reduce the amount of conventional dawn/dusk activity surveys required to assess trees with roosting potential and if any further survey is required it can be targeted much more effectively. Aerial survey is therefore a very useful and cost-effective technique for tree survey for bats.
BSG has been carrying out tree climbing surveys since 2007, all surveys being carried out by licenced bat workers qualified to climb trees. We are used to working closely with arboricultural consultants and tree surgeons.
We also provide a bespoke “bats and trees” training course which can be tailored to the needs of tree surgeons, site management staff, arboricultural consultants and local authority tree officers. The course provides guidance on assessing the potential of trees for bat roosts, and dealing with the practicalities of the legal protection afforded to bats.
The course is run by Principal Ecologist Guy Miller . Please contact Guy in our Derbyshire Office (01433 651869) if you are interested in receiving training, or if you would like to talk about commissioning an aerial tree survey.