Tree works during the bird nesting season
It is an offence to damage or destroy the nest of a wild bird while it is in use or being built. That applies all year, which is why a pre-works check matters more than the calendar.
Tree works during the nesting season are not banned by statute. What is banned, under section 1 of the Wildlife and Countryside Act 1981, is intentionally taking, damaging or destroying the nest of any wild bird while that nest is in use or being built. There is no date range in the Act. The practical rule that follows is simple: if a tree is being felled, pruned or cleared and a nest could be present, someone competent has to check first, and the check has to be recent.
Most contractors and councils work to a main season of March to August. That is a convention, not a defence.
The legal protection for nests and when it applies
The 1981 Act protects all wild birds, their nests while in use or under construction, and their eggs. Species listed in Schedule 1 carry additional protection: it is also an offence to disturb them while nest building, or while at or near a nest with eggs or young. Barn owls and kingfishers are the two most likely to appear on a development site.
Two points about the offence catch people out. First, it applies to the nest, not to the tree, so a tree with no preservation order and no planning condition is still protected by wildlife law if a bird is nesting in it. Second, "intentionally" covers proceeding when you knew or should have known a nest was there. A contractor who felled a hedge without looking has a weak position.
Enforcement sits with the police wildlife crime officer rather than the planning authority. The planning consequence is separate and can be worse: a breach discovered mid-scheme often stops work while the council decides what to do with the landscaping condition.
Why the season is longer than people assume
The March to August window covers the bulk of nesting activity for most common British species. It does not cover everything.
Tawny owls can be on eggs in February. Feral and woodpigeons nest opportunistically through much of the year, including December in mild winters. Long-tailed tits build in late February. Some species raise a second or third brood, so an August fledging is not the end of it.
The consequence is that "we waited until September" is a reasonable precaution and not a guarantee. Late summer and autumn works still need a walkover, just a quicker one. Conversely a February start is not automatically safe simply because the calendar says so.
Ivy-clad stems, dense scrub at the base of a tree and hedgerows are where nests are found most often, and they are also the parts of the job people treat as clearance rather than tree work.
Pre-works checks and who should carry them out
The check should be carried out by someone with the field skill to find a nest, which normally means an ecologist or an experienced arboriculturist trained in nesting bird identification. On a small householder job the tree surgeon may be competent to do it. On a site clearing several hundred metres of hedge, they are not.
A defensible sequence looks like this:
- Book the check for no more than 48 hours before works start, or 24 hours in the peak of the season.
- Walk every stem, hedge run and area of scrub to be affected, looking for nests, nest-building behaviour and adult birds carrying food or nest material.
- Where a nest is found, mark an exclusion buffer sized to the species and leave it undisturbed until the young have fledged and an ecologist confirms the nest is no longer in use.
- Record the check, the date, the time, the weather, who did it and what was found, including a nil return.
- Repeat the check if works are delayed by more than the agreed period.
Buffer sizes are a judgement call rather than a fixed number, and they depend on species, the type of work and screening. A tracked excavator working ten metres from a blackbird nest in dense scrub is a different proposition from a chainsaw in the same tree.
Working outside the season and the programme cost
The cheapest answer is usually to time the works. Clearance in late autumn or winter avoids the check, the buffers and the risk of a stop.
Where the programme cannot move, the cost is not the survey fee. It is the possibility that a nest is found on the day and a section of the site is off limits for three to six weeks. Price that risk rather than the check.
Where a scheme is being designed, the tree evidence and the ecology evidence should be commissioned together. An arboricultural survey to BS 5837:2012 identifies which trees are to be removed and which are retained, and a preliminary ecological appraisal identifies the habitats and the constraints that go with them. Running them separately is how sites end up with a felling schedule that conflicts with a nesting constraint nobody flagged.
Councils increasingly attach a condition requiring vegetation clearance outside the nesting season or subject to a pre-clearance check by a suitably qualified ecologist. Read that condition before you programme, because some versions require the check report to be submitted to the council in advance.
Bats in trees and the separate offence
Bats are a European protected species under the Conservation of Habitats and Species Regulations 2017, and the offence is different in kind. Damaging or destroying a breeding site or resting place is an offence whether or not a bat is present at the time, and whether or not the work is deliberate in the ordinary sense.
That means a winter felling window solves the bird problem and does nothing for the bat problem. A hollow limb, a lifted bark plate, a woodpecker hole or a split stem can all be a roost, and a roost is protected in January as much as in June.
Where a tree has bat roost potential, the sequence is a preliminary roost assessment by a licensed ecologist, then any further survey they specify, then a mitigation licence from Natural England before works. That licence takes time to obtain. A protected species survey must be carried out by a suitably licensed ecologist under the Wildlife and Countryside Act 1981 and the 2017 Regulations, and no draft document substitutes for that person.
Recording the check so it stands up later
The record is what protects you if the works are questioned. Keep it short and keep it contemporaneous.
A one-page pro forma per visit works well: site and compartment reference, date and time, surveyor name and qualification, weather, the method used, a plan marked with the areas checked, findings including nil returns, any buffers imposed with their radius, and the date works were authorised to proceed. Photographs of marked buffers help.
Where a nest is found, add the follow-up: the date fledging was confirmed, by whom, and the date the buffer was released. Councils discharging a landscaping or ecology condition will accept a clear log far more readily than a retrospective statement.
Keep the records with the site file for the life of the development, rather than only until practical completion.
Browse the full set of planning report types to see which ecology and arboriculture documents a site usually needs before clearance begins.
PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it.
Frequently asked questions
Is it illegal to cut trees between March and August?
No. The Wildlife and Countryside Act 1981 protects the nest of a wild bird while it is in use or being built, with no fixed dates in the legislation. March to August is a working convention because that is when most species nest. Works can proceed in that window if a competent pre-works check confirms no active nests are present.
Who should carry out the nesting bird check?
Someone able to find and identify a nest in the field, which usually means an ecologist or an arboriculturist trained in nesting bird identification. On a single garden tree an experienced tree surgeon may be competent. On extensive hedgerow or scrub clearance, or where a planning condition names a suitably qualified ecologist, appoint one.
How long before works should the check be done?
No more than 48 hours before clearance starts, and 24 hours during the peak of the season. Birds can begin building quickly, so an older check does not describe the current position. If the works slip beyond that window, repeat the check and record the second visit.
What happens if a nest is found once works have started?
Stop work in that area immediately, mark a buffer around the nest sized to the species and the type of work, and leave it undisturbed until an ecologist confirms the young have fledged. Record the find and the date the buffer was released. Continuing to work having seen a nest risks committing an offence.
Does felling in winter avoid all wildlife issues?
It avoids nesting birds but not bats. Damaging or destroying a bat roost is an offence under the Conservation of Habitats and Species Regulations 2017 whether or not bats are present at the time. A tree with hollow limbs, lifted bark or split stems needs a preliminary roost assessment by a licensed ecologist before any winter felling.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.