Every UK bat species has full legal protection under wildlife law, and that protection extends to their roost sites in trees.
A tree surgeon who disturbs or destroys a bat roost without a preliminary assessment in place commits a criminal offence, and so does the landowner who commissioned the work.
Getting the process right isn’t complicated once you know what it involves.
This guide covers the advice you need before any cutting or structural work on mature trees in Scotland goes ahead.
How Bats Use Trees – Advice from Expert Tree Surgeons
Bats use trees as roosts and for far more besides.
Mature trees and woodland provide feeding corridors and commuting routes between roost sites, with bats following tree lines at night while they forage for insects.
Many species use echolocation to hunt their prey in the air, and a hedgerow or a run of mature trees gives them the structure they need to move efficiently across a landscape.
Varied tree cover and hedgerow planting also helps encourage a variety of insects that bats depend on as a food source.
The roost features themselves can be subtle.
Bats prefer sheltered crevices where the temperature stays relatively stable, and they find these in loose bark, cracks in older wood, woodpecker holes, crevices in branch junctions, and natural cavities that form as timber ages.
A tree doesn’t have to look decayed or hollow to hold a roost.
A reasonably sound trunk with a few bark splits can be all a pipistrelle needs to shelter through the day.
Bat Species Found in Scottish Trees
Several bat species are regularly found roosting in Scottish trees.
The pipistrelle is by far the most common bat in Scotland and will use crevices in bark and gaps in mature woodland trees, some have even been found nesting in thick ivy.
Brown long-eared bats favour tree holes in older woodland.
The barbastelle, a rarer species of significant conservation concern, has a strong association with loose bark on mature woodland trees and is among the bat species found at higher woodland sites across Scotland.
Other bat species found across Scotland include Daubenton’s bat, Natterer’s bat, and the lesser horseshoe bat in some southern areas.
Each prefers different roost features. This is why a preliminary assessment looks at the specific characteristics of the tree rather than simply whether bats have been observed nearby.
Legal Protection for Bats, Their Roosts, and Woodland
Bats and their roosts are protected under the Conservation of Habitats and Species Regulations 2017 and the Wildlife and Countryside Act 1981.
All UK bat species are classified as European Protected Species, and that classification means the legal protection around them is more stringent than for most other UK wildlife.
Roosts are protected by law in both their occupied and unoccupied states.
A tree used as a summer maternity roost holds the same legal protection in midwinter when it’s empty, and roosts are protected whether bats are present at the time of the work or not.
Destroying, damaging, or obstructing a bat roost is an offence, and so is disturbing bats in a way that affects their ability to survive and breed.
Bat roost sites can also coincide with trees that have a Tree Preservation Order in place. They add a second legal layer to any planning decisions around proposed work.
Getting advice early on what permissions and assessments apply prevents delays further down the line.
When Do Tree Works Need a Bat Survey?
Any work that could affect a tree with potential bat roost features needs at least a Preliminary Roost Assessment (PRA), known for trees as a Ground Level Tree Assessment (GLTA), before it goes ahead.
A qualified ecologist carries out the GLTA, inspecting the tree from the ground for cavities, deadwood, bark separation, woodpecker holes, and other potential roost features (PRFs).
There are also physical signs that a tree is already in active use.
Bat droppings below holes or at the base of the trunk, grease stains or urine staining around an entry point, and audible squeaking or chittering from inside the tree on warm evenings are all indicators that bats are present.
A GLTA picks up on these signs alongside the structural features.
Where the assessment identifies plausible roost features, bat surveys are the next step.
These are emergence and re-entry surveys, carried out at dusk and dawn when bats leave or return to the roost.
The number of visits required depends on the season and the species likely to be present.
Where bats present in the tree are confirmed, the ecologist assesses the scale of impact the proposed work would have, They then advise whether it can proceed with precautionary modifications or whether a European Protected Species licence application to NatureScot is needed.
Timing Tree Work Around Bat Roosts
The timing of tree work relative to the bat calendar matters considerably.
Maternity roosts, where female bats gather to give birth and raise young, are most sensitive between May and August. This is when disturbance risk is highest.
Bats also feed heavily through autumn before hibernation begins from late October.
October through to early March is generally lower risk, though the legal protection on bat roosts applies all year regardless of the season.
Even winter work on a veteran tree with a historic roost technically requires a preliminary assessment to confirm the roost isn’t occupied.
Building assessment and survey timing into a project from the start is straightforward.
Trying to factor it in after a start date has already been committed to is considerably harder.
Bats and Nesting Birds
Bats share tree habitat with nesting birds across many Scottish sites, and a veteran tree with bat roost potential will often attract hole-nesting bird species as well.
Disturbing an active bird nest during the bird breeding season between March and September is also a criminal offence under the Wildlife and Countryside Act.
Both risks can be assessed together at the preliminary inspection stage.
It is one of the practical reasons to get a survey arranged before committing to dates for any major tree removal or crown reduction work.
What to Do if Bats Are Present During Tree Work
If a bat is found or bats emerge unexpectedly during tree work already underway, work must stop immediately on the affected section of the tree.
Bats should not be handled unless a licensed bat handler is present.
The Bat Conservation Trust helpline can provide guidance on what to do next. NatureScot can advise on whether emergency licensing is available where work cannot safely pause for an extended period.
Resuming work around a confirmed bat roost without the appropriate permit or licence in place is an offence, regardless of how the job was planned at the outset.
Getting an arboricultural assessment done before work starts is how you avoid finding bats mid-job.
How We Carry Out Tree Work Near Bat Roosts
Our tree surgery teams across Scotland hold arboricultural qualifications and carry out work on trees where bat roost checks may be required.
We provide training to our site teams so they know the indicators to look for and when to stop and seek specialist advice before work continues.
Where a project requires a bat survey or an ecology report, we work alongside licensed ecologists to keep things moving without cutting corners.
For tree removal, crown reduction, or major pruning on veteran and mature trees, we can advise from the outset on whether a preliminary roost assessment is likely to be needed so the project timeline accounts for it from the start.
If you already have an ecology report and a NatureScot licence in place, we can work within the conditions it sets out.
Bats and Tree Work: Common Questions
Is it illegal to cut down a tree with bats in?
Yes. Felling or significantly working on a tree with an active bat roost without a European Protected Species licence from NatureScot is a criminal offence under the Conservation of Habitats and Species Regulations 2017. The protection applies to historic roosts too, not just trees where bats are actively occupying the roost at the time of the work.
What do bats do in October?
October marks the start of the bat hibernation period. Bats feed heavily in the preceding weeks before settling into hibernation from late October, though they may still emerge on warmer nights. Hibernation roosts are often different sites from summer roosts, so a tree used as a maternity roost between May and August may be unoccupied by November, but the roost site retains its legal protection all year.
Do bat roosts affect planning permission for tree work?
Yes, in some cases. Where a bat survey confirms a roost in a tree that’s being considered for removal or significant works, a European Protected Species licence from NatureScot may be required before any planning permission or Tree Preservation Order consent can be acted upon. The ecology report feeds into any application as supporting evidence, so the survey process and the planning process run in parallel rather than one waiting on the other.
Get Advice on Bat Licences and Book a Tree Survey in Scotland
If you’re planning tree work on mature trees across Glasgow, Edinburgh, or wider Central Scotland and you’re not sure whether bat roost checks apply, speak to our team before anything goes ahead.
We carry out tree surveys in Glasgow and across Scotland, and we can advise from an early stage on what assessments are needed.
For advice on tree removal, planting programmes following works, pruning special trees, or bat-aware arboricultural planning, call us on 07946 322717 or get in touch online to book your free survey.