Wildlife checks before felling a tree

Wildlife checks before felling are not a courtesy and they are not part of the consent for the works. Tree consent under a Tree Preservation Order, a conservation area notice or a felling licence tells you whether you may remove the tree. Wildlife law tells you whether removing it on that day, in that way, would be an offence. The two regimes run separately, and a contractor holding a valid consent can still commit an offence by putting a saw into an occupied bat roost or an active nest.

The two that catch almost everyone are roosting bats and nesting birds. Everything else is a smaller risk on most sites.

The legal protection that applies

All British bat species are European protected species under the Conservation of Habitats and Species Regulations 2017. The offences include deliberately killing, injuring or capturing a bat, deliberately disturbing bats in a way that affects their ability to survive, breed or rear young, and damaging or destroying a breeding site or resting place. That last offence does not require intent, which is the point most contractors miss. Not knowing the roost was there is not a defence.

Birds are protected by the Wildlife and Countryside Act 1981. It is an offence to intentionally kill, injure or take any wild bird, and to intentionally take, damage or destroy the nest of any wild bird while it is in use or being built. Some species carry higher protection and additional offences around disturbance.

Other species occasionally matter in trees. Hazel dormice use tree and scrub habitat and are European protected species. Certain invertebrates associated with veteran trees and deadwood carry protection. Badger setts are occasionally found in the root plate of a mature tree.

Assessing a tree for roost potential

The standard first step is a preliminary roost assessment, carried out from ground level with close-focusing binoculars and a high-powered torch, sometimes with an endoscope where features are reachable. Each tree is categorised for its potential to support roosting bats, from negligible through low and moderate to high, following the good practice guidelines published by the Bat Conservation Trust.

The categorisation drives everything that follows. Negligible potential means the works can proceed with a watching brief. Low potential often means a climbed inspection or a single emergence survey. Moderate and high potential trigger a sequence of emergence and re-entry surveys in the active season, and that is where programmes lose months.

A bat survey has to be carried out by a suitably licensed ecologist, and this is a report type where a licensed professional is legally required rather than merely advisable. An AI-assisted draft can structure the reporting, but the field evidence has to come from the person holding the licence.

The features that indicate roosting potential

Worth knowing even if you are not the surveyor, because these are what an arboriculturist should be flagging during a condition survey.

• Woodpecker holes and other cavities, particularly where the entrance is small and the void extends upward.
• Rot holes at branch junctions and old pruning wounds.
• Lifting or loose bark, especially on dead or dying limbs where the plate is still attached.
• Frost cracks and longitudinal splits in the stem.
• Hazard beams and partially detached limbs with a cavity behind.
• Dense ivy cover, which both hides features and provides roosting space in its own right.
• Knot holes, canker and any feature with staining or smoothing around the entrance.

Ivy is the awkward one. Clearing ivy to inspect the trunk is itself capable of destroying a resting place, so the clearance has to be supervised rather than done in advance to make the survey easier.

Timing through the year

The seasons pull in opposite directions, which is why felling windows are narrower than people expect.

The autumn window is short and it is when every scheme wants to fell. Book the ecologist early.

Felling outside the nesting season is not automatically safe either. Some species nest early and some nest late, and a pre-works check within a short period before the works, by someone competent to carry it out, is the standard control. A check done three weeks before felling has very little value.

Soft felling and ecological supervision

Where a tree has low or moderate potential and the survey evidence does not establish a roost, the usual control is soft felling under supervision rather than a licence.

The method is deliberate. Sections are cut so that features are not crushed, lowered gently rather than dropped, and laid on the ground with the cavity opening upward. The ecologist inspects each section as it comes down. Material containing features is left in place overnight so that any bat present can leave under its own power, and is inspected again the following morning before chipping.

Two practical points. The climber needs to know which features to avoid before the first cut, so mark them. And the programme has to allow for the works to stop entirely if a bat is found, because at that point the work becomes unlawful without a licence.

That stop is the reason to do the assessment early. Discovering a roost on the day costs far more than surveying for one in advance, and the same logic applies to street trees, highway works and utility trenching, where the discovery usually happens with a road closed.

When a licence is required

Where the works will damage or destroy a roost, a European protected species licence from Natural England is needed before the works proceed. The licensing tests require a qualifying purpose, an absence of a satisfactory alternative, and that the favourable conservation status of the species is maintained.

Applications need survey evidence, a method statement, a mitigation and compensation scheme and, usually, a planning permission already in place. A registered consultant may be able to use a class licence for lower-impact situations, which is faster, but it has its own eligibility limits.

Budget months rather than weeks. Where an arboricultural impact assessment identifies trees for removal, the ecological check should run alongside it rather than after permission.

Records to keep

The paperwork is what protects the client if a complaint is made, so keep it properly: the preliminary roost assessment with the category given to each tree and the date, any emergence survey results with weather conditions, the pre-works nesting check with the name of the person who did it, a supervision record for the felling itself, photographs of features before and after, and any licence with its return.

Store it with the site file rather than with the contractor. And where a felling licence was also required, that consent sits alongside these records rather than replacing them, as woodland felling licences and when planning is not enough sets out.

Enter your postcode on PlanScope to see which tree and ecology documents your site is likely to need.

This is general guidance, not legal advice. Bat survey work and licence applications require a suitably licensed ecologist. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.