01 Mar Tree climbing survey for bats
Tree climbing surveys (sometimes known as aerial inspection surveys) are an effective way to assess a tree’s potential to support bats. This technique, which uses access skills borrowed from tree surgery, is far more definitive than ground-based survey, and can be very cost-effective.
Trees with features such as woodpecker holes, areas of loose flaking bark, splits, cavities or even thick ivy cover can provide roost sites for bats. Many projects, including site development or arboricultural operations, require the removal or pruning of trees.
Where there is a reasonable likelihood of the bats in trees, planning authorities have a duty to consider impacts on the species and their roosts, and will rely on survey information when considering planning applications. The legal protection afforded to bats and their roosts also means that care needs to be taken by others when felling trees or branches with cavities or other suitable roosting features. The need for survey is often very clear and it is important that the survey is undertaken to a high standard, is as conclusive as possible, and is undertaken in a cost-effect way.
The advantages of tree climbing surveys
A ground-based visual assessment can only reliably scope-out the presence of bats in trees when no cavities are present, or where the features present can be fully viewed from ground level and are too shallow or exposed to offer sheltered roosts.
Relying on ground-based activity surveys alone (e.g. dawn survey for bats returning to roosts) is a labour-intensive approach, restricted to the active period (primarily May-September). Without first carrying out climbing inspections, it also risks wasted effort.
Tree climbing surveys can be undertaken at any time of year. It is often possible to climb several trees in a day, making this a cost-efficient approach.Tree climbing surveys allow potential roost features to be accessed and checked at close quarters, with a torch and an endoscope for evidence of bat activity. Significantly, many features which appear suitable from ground level can often be ruled out on close inspection. This means the requirement for further survey or mitigation can often be avoided. Where ground-based activity survey is still required, it can be targeted far more effectively.
BSG Ecology has climbed hundreds of trees throughout England and Wales, in parkland, woodland, hedgerows, urban areas, and on many proposed development sites.
We provide advice to major infrastructure projects as well as smaller developments, schools, highways, and nature reserves; and we provide support to tree officers, site managers, arboricultural consultants, tree surgeons and developers. Our experience of obtaining licences for work involving bats is extensive and spread throughout the practice, and we provide training in relation to bats and trees.
We employ numerous bat-licensed ecologists within the practice. Guy Miller a qualified tree climber, leads the tree survey team.
Please contact Guy Miller for further information:
Hathersage: 01433 651869