Every spring, the same question comes up on construction sites across the UK: "Can we clear this vegetation, or is it nesting season?"
The answer matters. Destroying an active bird's nest is a criminal offence that can result in an unlimited fine and up to six months in prison. Getting it wrong can also halt your construction programme for weeks while you wait for chicks to fledge.
This guide explains the law, the nesting season dates, what checks are required, and how to plan vegetation clearance to avoid delays.
When Is Nesting Bird Season?
The main nesting bird season in the UK runs from 1 March to 31 August. During this period, the vast majority of UK bird species are building nests, incubating eggs, or raising chicks.
However, this is a guideline, not a hard legal boundary. Some species nest earlier - raven and crossbill can begin nesting in February. Others may still have active nests into September, particularly after a late start to the season or if they have had a failed first brood and re-nested.
The law does not define a specific nesting season. It protects nesting birds whenever they are nesting, regardless of the date. This means even vegetation clearance in February or September could be an offence if active nests are present.
What Does the Law Say?
The Wildlife and Countryside Act 1981 makes it an offence to:
- Intentionally kill, injure, or take any wild bird
- Intentionally take, damage, or destroy the nest of any wild bird while it is in use or being built
- Intentionally take or destroy the egg of any wild bird
Schedule 1 species (including barn owl, peregrine falcon, kingfisher, and others) receive additional protection. It is also an offence to intentionally or recklessly disturb these species while they are at or near a nest containing eggs or young.
Penalties can include an unlimited fine and/or up to six months imprisonment per offence. Each nest or egg destroyed is a separate offence.
The key word is "intentionally." If you know or should reasonably know that nesting birds are present and you proceed with clearance anyway, you are committing an offence. Ignorance is not a defence if a reasonable person would have checked.
What About Hedgerow Regulations?
Separate from bird protection, the Hedgerow Management Rules (part of cross-compliance for agricultural land) prohibit cutting or trimming hedgerows between 1 March and 31 August on agricultural land and land adjacent to agricultural land.
This is a specific date-bound prohibition, unlike the Wildlife and Countryside Act which protects nests whenever they are active. However, the hedgerow rules apply to agricultural hedgerows, not necessarily to hedgerows on development sites - although the bird nesting protections still apply everywhere.
Vegetation Clearance on Development Sites
For development sites, the practical approach is:
Outside Nesting Season (September to February)
Clear vegetation during this period wherever possible. This is the safest legal approach and avoids the need for nesting bird checks.
Best practice: Complete all vegetation clearance - trees, hedgerows, scrub, rough grassland, bramble - before 1 March. If your programme allows it, this is always the preferred option.
During Nesting Season (March to August)
If vegetation clearance is unavoidable during nesting season, a nesting bird check must be carried out by a suitably qualified ecologist immediately before the work begins.
The ecologist will:
- Search all vegetation to be cleared for active nests
- Check for signs of nesting activity - birds carrying food or nesting material, alarm calling, reluctance to leave an area
- Provide a written statement confirming whether nests are present
If no active nests are found: Clearance can proceed, but should start immediately after the check (ideally the same day). If there is a delay of more than 24-48 hours, the check should be repeated as birds can begin nesting very quickly.
If active nests are found: Work in that area must stop. An exclusion zone should be established around the nest (typically 5-10m depending on the species). Work cannot resume in that area until the nest is no longer active - meaning the chicks have fledged and left. This can take 4-6 weeks from egg laying.
Pre-clearance Nesting Bird Surveys
For larger sites, a more structured approach involves:
- A pre-clearance survey of the entire site 24-48 hours before clearance begins
- Marking nest locations with exclusion zones
- Phased clearance starting from areas confirmed clear of nests
- Repeat checks as clearance progresses
Planning Conditions
Many planning permissions include conditions requiring vegetation clearance to take place outside nesting season, or requiring a nesting bird check if clearance during the season is unavoidable. Check your planning conditions before scheduling clearance work.
Your Construction Environmental Management Plan (CEMP) should include a protocol for nesting bird checks if any phase of the works involves vegetation removal during March-August.
The ECoW Role
On construction sites with an Ecological Clerk of Works, the ECoW is responsible for:
- Conducting nesting bird checks before vegetation clearance
- Advising the site manager on exclusion zones around active nests
- Monitoring nests until chicks have fledged
- Recording all nest findings in the site ecological log
- Delivering toolbox talks to the site team about nesting bird awareness
Common Questions
Can I move a nest?
No. It is an offence to move or relocate an active nest, even with good intentions. The nest must be left in place until the breeding attempt is complete.
What if I find a nest after clearance has started?
Stop work immediately in that area. Establish an exclusion zone. Contact the project ecologist. Do not resume until the nest is no longer active.
Do I need a licence?
No licence is required for nesting bird checks or for working near nesting birds (except Schedule 1 species). However, the ecologist conducting the checks should be suitably qualified and experienced.
What about ground-nesting birds?
Some species nest on the ground - skylark, lapwing, little ringed plover, oystercatcher. Rough grassland, bare ground, and gravel areas on construction sites can be attractive to ground nesters. Check these areas as well as trees and hedgerows.
Plan Ahead
The simplest way to avoid nesting bird delays is to plan vegetation clearance for the autumn and winter months. If that's not possible, factor in the time and cost of nesting bird checks and potential exclusion zones.
Before you start any clearance, run a desktop study to understand what species have been recorded near your site. If there are barn owl records within 500m, you need to be much more cautious than if the only nearby records are common garden species.
EcoCheck shows you protected species records for any GB location instantly, including barn owl, peregrine falcon, and other Schedule 1 species. Use it to scope your nesting bird risk before you arrive on site.
Patrick O'Connor is a Freelance Ecologist at Kinterra Consulting and the developer of EcoCheck - an instant ecological desktop assessment tool for any GB location. Try it free for 3 days at ecocheck.co.