Nesting birds
No removal of trees, scrub or hedges, should be carried out between the 1 March and 31 August inclusive in any year, unless searched beforehand by a suitably qualified ornithologist. All the UK’s native birds are protected from disturbance during breeding under the Wildlife & Countryside Act 1981 (as amended).
Bats and trees
If a development proposal will involve the felling of trees, no trees on site should be felled until a bat mitigation scheme has been submitted to the Local Planning Authority (LPA).
This should include the results of a survey to determine which trees contain or are likely to contain bat roosts (those with cracks, rot holes, splits, dense ivy cover, etc) and mitigation measures if they need to be removed. Some trees on site may contain features which could be used by roosting bats. If any of these are due to be removed as part of the development, they need to be checked for evidence of use by bats beforehand.
Because bats are such a mobile species, the survey should be carried out as close to the time of felling as possible. Any that are found to contain bats will need to be left until the bats have gone or been excluded (which would require a licence), although it would be preferable to retain on site those specimens considered likely to be used by them.
Felling techniques on all trees with potential bat habitat must be felled following all guidelines in ‘Trees and Bats’ (Arboricultural Association Guidance Note 1, May 2003, 2nd Ed), and in the presence of a bat ecologist. If bats are discovered Natural England will need to be consulted and a DEFRA (Department of Food and Rural Affairs) licence will need to be obtained prior to any recommencement of work, and mitigation measures proposed.
All bats and their roosts are legally protected by the Wildlife and Countryside Act 1981 and the Conservation (Natural Habitats & c.) Regulations 1994. If bats are present it is illegal to intentionally kill, injure or catch them, damage, destroy or obstruct their roosts, or to disturb bats. Bat roosts are also legally protected, even when bats are not present all of the time.
Timing of tree works
To reduce the chance of disturbing a bat roost, it is important to avoid the summer (breeding season) and winter (hibernation) months. Works to trees with potential for bats is best done from late August to early October when young bats are mobile and on the wing, female bats are unlikely to be pregnant and the hibernation season has not yet begun.
March to April is also a suitable time, though consideration should also be given for nesting birds as these are also protected by law. Crown pruning and minor tree works can also be completed over the winter months. The removal of potential roost sites during this time should be avoided, as some bat species hibernate in trees.
Best practice
- Keep tree work to a minimum retaining all potential roosts where possible.
- A precautionary inspection of the tree(s) by the tree work contractor looking for signs of bats should be carried out before starting work. This should include an inspection of all holes and niches using a torch and preferably an endoscope. If bats or signs of bats are found, no work should start and Natural England should be contacted for further advice.
- Where possible, avoid cross cutting in proximity to cavities or hollows.
- Limbs with internal fissures should be pruned carefully to maintain integrity of features as potential roost sites.
- Any sections felled containing cavities should be lowered carefully and left on the ground (preferably for 24 hours) with the openings clear, allowing anything inside an opportunity to escape.
- Split limbs that are under tension may need to be wedged open to prevent their closure when pressure is released, potentially trapping bats.
If ivy covers areas of a tree’s trunk or branches, there is roosting potential behind it. In addition, potential roosts in the tree may also be hidden behind the ivy.
Dealing with ivy-covered trees depends on the amount of growth. If there is a thick mass of ivy growth, it may be practical to consider felling the tree on the basis that the thickness of the foliage will soften the fall and reduce the shock. This tree can then be inspected on the ground and if possible left for 24hours, before section cutting. If the tree is only partially covered, pruning or sectioning may be more appropriate.
If the works are not urgent, cutting the ivy at its base and completing the work when the ivy is dead, thus reducing the bat roosting potential should be considered. However ,where stems of ivy create a dense mass against the trunk, there will always be roosting potential.
