Do I Need a Reptile Survey? – Survey Methods and Timing

If you are preparing a planning application, one of the most common ecological questions is: Do I need a reptile survey?

Reptiles are widespread across the UK and may be present on many development sites, particularly where suitable habitat exists, such as rough grassland, scrub, or unmanaged field margins. Because several native reptiles are protected under legislation, local planning authorities often require survey evidence before determining an application.

Understanding when surveys are needed and how they fit into the wider planning process can help developers avoid delays, unexpected costs, and compliance risks.

In the UK, reptiles include species such as slow worms, grass snakes, common lizards, smooth snakes and sand lizards. These species are protected under the Wildlife and Countryside Act 1981, making it an offence to intentionally kill or injure them.

From a planning perspective, the presence of reptiles is a material consideration. Planning authorities must ensure development proposals properly support reptiles and safeguard biodiversity where required.

Sites most likely to trigger survey requirements typically include:

• Rough grassland or unmanaged land
• Brownfield sites with recolonising vegetation
• Land close to woodland or railway corridors
• Sites with south-facing banks or rubble piles
• Areas with known local reptile records

Where these features are present, an ecologist may recommend further assessment.

Not every development site requires reptile surveys. The need is usually identified during a Preliminary Ecological Appraisal (PEA), which assesses habitat suitability and the potential presence of protected species.

A reptile survey is more likely to be required where:

• The site contains a suitable habitat for reptiles
• The proposal involves ground clearance or vegetation removal
• Local records indicate species of reptile nearby
• The site forms part of a wider habitat network
• Planning conditions specifically request further survey work

Local planning authorities expect ecological risks to be addressed early. Leaving surveys too late in the programme can create avoidable planning delays and seasonal constraints.

Where surveys are required, ecologists use standardised approaches to determine presence, likely population size, and distribution across the site.

The most common method involves artificial refugia. This typically includes:

• Carefully placing mats or tins in suitable reptile habitats
• Allowing reptiles time to begin using these refugia
• Undertaking a series of structured site visits
• Recording weather conditions and reptile observations
• Mapping distribution patterns across the site

This approach provides robust evidence to inform planning decisions and any required mitigation. Survey effort is always proportionate to risk. Sites with higher habitat suitability or larger footprints may require additional visits to establish reliable results.

Timing is critical when planning to carry out a reptile survey. Reptiles are only active during certain months, meaning surveys are seasonally constrained.

The optimal survey window is typically April, May and September, when reptiles are active but not suppressed by peak summer heat. During these periods:

• Reptiles are more likely to bask under refugia
• Detection rates are highest
• Survey data is considered robust by planners
• Fewer repeat visits are usually required

Surveys may sometimes extend into suitable early autumn weather, but winter surveys are not considered valid. Early ecological advice is therefore essential to keep development programmes on track.

Finding reptiles on site does not automatically prevent development. In most cases, a well-designed mitigation strategy allows projects to proceed while remaining compliant.

Typical mitigation approaches may include:

• Sensitive vegetation clearance (often called a phased cut)
• Habitat manipulation to encourage reptiles to move
• Installation of reptile exclusion fencing
• Supervised translocation to receptor sites
• Creation of enhanced reptile habitats within the scheme

The appropriate approach depends on the species present, population size, and site context.

For higher-value species such as sand lizard and smooth snake, which are European Protected Species under the Conservation of Habitats regulations, licensing requirements are more complex and must be carefully planned.

Reptile surveys form part of the wider ecological evidence base submitted with a planning application. Planning officers rely on this information to understand potential impacts and determine appropriate planning conditions.

Typically, survey findings feed into:

• Ecological reports submitted with planning
• Site layout design and habitat retention
• Construction method statements
• Biodiversity Net Gain strategies
• Long-term habitat management plans

Engaging a suitably qualified ecologist early helps ensure surveys align with planning expectations and seasonal constraints.

Are reptile surveys always required?

No, surveys are only required where habitats on site are considered suitable or where local records indicate potential presence. A Preliminary Ecological Appraisal is normally the first step in determining risk. Many low-risk sites can be scoped out early, but where suitable habitat exists, planning authorities will usually expect further survey work.

What time of year is best for reptile surveys?

The optimal period is typically April, May and September, when reptiles are active, and detection rates are reliable. Surveys outside these months are often considered suboptimal and may not be accepted by local authorities. Programming surveys early in the project timeline is therefore very important.

Will reptiles stop my development?

In most cases, no. The majority of sites can proceed with appropriate mitigation and careful site management. The key is identifying constraints early so proportionate measures can be designed into the scheme. Only in rare circumstances do reptiles significantly constrain development potential.

How long does a reptile survey take?

Most standard presence/likely absence surveys require multiple site visits over several weeks during suitable weather. The exact duration depends on habitat quality, site size, and survey objectives. Your ecologist will advise on the appropriate level of effort needed to support your planning application.

Working with an experienced ecological consultant helps streamline the survey process and reduce risk.

At Collington Winter Environmental, our team supports developers through each stage, from initial habitat assessment through to mitigation design and discharge of planning conditions. Our Director holds Natural England protected species licences and has extensive experience advising on reptile constraints across a wide range of projects.

Early advice is often the key to avoiding seasonal delays and keeping development programmes moving.

If you are unsure whether you need a reptile survey, contact Collington Winter Environmental today via info@collingtonwinter.co.uk or by submitting our contact form above for pragmatic, planning-focused advice.