When is Nesting Bird Season in the UK? A Developer Guide

If you are planning vegetation clearance or tree work, understanding when nesting bird season in the UK occurs is essential. Wild birds and their nests are protected by law, and disturbing nesting birds can lead to planning delays, legal risk and reputational issues. For developers and landowners, early ecological awareness is the simplest way to keep projects compliant and on programme.

This guide explains the typical bird nesting season, what the law requires and how to manage risk on development sites.

Bird nesting season in the UK generally runs from March to August inclusive. During this period, many bird species build their nests, lay eggs and raise dependent young.

However, it is important to understand that nesting activity does not strictly follow the calendar. In practice:

• Nesting can occur outside these months in milder weather and winter
• Some species start early (sometimes February)
• Others may continue into September
• Legal protection applies whenever nests are active

Because of this variation, planners and ecologists focus on the presence of active nests, rather than relying solely on seasonal dates.

Under the Wildlife and Countryside Act 1981, all wild birds, including their nests, are protected while in use or being built. It is an offence to intentionally damage or destroy:

• The nest of any wild bird while in use
• Eggs or dependent young
• Activities that disturb any wild bird at the nest

For development sites, this means that site clearance, demolition and tree work must be carefully timed and managed.

Local planning authorities routinely expect developers to demonstrate that works will not harm nesting birds, particularly where suitable habitat is present.

Nesting bird constraints most commonly affect projects involving vegetation removal or structural changes.

Higher-risk activities include:

• Tree work and arboricultural operations
• Hedgerow removal
• Scrub clearance
• Demolition of buildings with roof voids
• Site strip or ground clearance

Sites with dense vegetation, buildings with ledges, or areas showing clear bird activity are particularly sensitive.

Early ecological input helps identify these risks and consider mitigation measures before they affect the programme or planning.

Where nesting bird potential exists, an ecologist will usually undertake a Preliminary Ecological Appraisal and, where necessary, targeted checks.

The assessment typically considers habitat suitability, evidence of bird activity, the presence of nesting material, the timing of work and the potential impacts of the proposed development.

If work are planned during the bird nesting season, a pre-commencement nesting bird check is often recommended. These checks are normally carried out shortly before vegetation clearance begins to confirm whether active nests are present and to ensure work can proceed lawfully.

Finding active nests does not usually prevent development, but it does require careful management.

Typical responses may include:

• Establishing a temporary buffer around the nest
• Delaying work in that specific area
• Monitoring nest status
• Phasing vegetation clearance
• Adjusting the construction programme

Work can usually continue in other parts of the site where no active nests are present.

The key principle is straightforward: you must not disturb nesting birds or destroy the nest while it is in use.

Yes, but only with appropriate safeguards in place.

Many development projects proceed during the bird nesting season in the UK, provided suitable checks and ecological supervision are undertaken. Best practice typically involves avoiding vegetation clearance where possible, carrying out nesting bird surveys immediately before work, implementing exclusion zones where required and programming higher risk work outside peak season where feasible.

Delaying work until autumn or winter can sometimes simplify site clearance, but this is not always practical. A proportionate, site-specific approach is usually the most effective solution.

Planning authorities increasingly expect ecological risks to be addressed at an early stage.

Failure to consider nesting birds can lead to planning conditions requiring late surveys, requests for additional ecological reports, delays to site clearance and potential enforcement risks.

By contrast, early ecological input provides certainty and helps maintain programme momentum. Nesting bird considerations often feed into wider ecological reports submitted alongside planning applications, particularly where habitats are being removed.

When is nesting bird season in the UK (legally defined)?

There is no fixed legal season in the UK. While the main bird nesting season typically runs from March to August, the law protects active nests whenever they occur. Developers must therefore consider nesting risk at any time of year where suitable habitat is present.

Can tree work be carried out during bird nesting season?

Tree work can proceed during the season, but only where it can be clearly demonstrated that no active nests will be affected. In most cases, a nesting bird check by a qualified ecologist is recommended immediately before works begin to ensure compliance.

What happens if I accidentally disturb a bird nest?

Disturbing an active nest may constitute an offence under the Wildlife and Countryside Act 1981. If a nest is discovered during works, activities should stop in that area immediately, and ecological advice should be sought to agree on appropriate next steps and avoid committing an offence.

Do planning authorities always require bird surveys?

Not always. Requirements depend on habitat suitability and the nature of the proposed works. However, sites involving vegetation clearance are commonly subject to nesting bird considerations, either through planning conditions or supporting ecological reports.

Managing nesting bird risk is usually straightforward when considered early in the project lifecycle. At Collington Winter Environmental, we advise developers and landowners on pragmatic, proportionate approaches to nesting bird constraints. From initial site appraisal through to pre-commencement checks and ecological supervision, our team helps ensure projects remain compliant while progressing efficiently.

If you are planning site clearance or are unsure about nesting bird season in the UK, contact Collington Winter Environmental today via info@colligntonwinter.co.uk or by using our enquiry form at the top of this for clear, practical advice.