Tools, Ecology

Ecology survey calendar.

Many ecology surveys can only be carried out at certain times of year. Miss the window, and a planning application can stall for months. This calendar shows when each survey can be done, and what a closed window means for your programme.

Protected-species surveys are tied to when animals are active, so they can only be done in season. If a project reaches the point of needing a survey once its window has closed, you wait, sometimes the best part of a year, because the local planning authority will not validate or determine the application until the survey is done. The calendar below shows the standard windows for the surveys that most often affect residential and rural projects. Tap any survey for detail.

What it means for you

The cheapest survey is the one you did not have to wait a year for.

The single most useful thing you can do is commission a Preliminary Ecological Appraisal (PEA) early. It can be done at any time of year, and it tells you which of these seasonal surveys your site will actually need, before timing becomes a problem. Discover a great crested newt requirement in July, and you may have missed the whole eDNA window until the following April.

One thing that catches people out: most of these surveys need several visits spaced two to four weeks apart, so the practical deadline to commission is often weeks before the window's calendar end. That is why an ecologist may tell you a season has closed even while a calendar still shows it open. For bats, for example, the reliable window to start a fresh survey sequence typically closes in mid-August, not at the end of the month.

We do not carry out the surveys ourselves, ecologists do. What we do is build the survey programme into your planning strategy from the outset, coordinate the right specialists, and give you a realistic timeline, so ecology is a managed step rather than a nasty surprise that costs you a building season.

Please note: This calendar is general guidance, not formal ecological advice. Survey requirements, methods and timings are specific to each site and change with guidance and conditions on the ground. Always confirm what your project needs with a qualified ecologist before relying on these windows. For help building ecology into your planning programme, please get in touch.

Get in touch

Plan ecology in from the start.

Tell us about your site and where you are in the process. We will help you sequence the surveys and keep your programme on track.

Sources

Where these windows come from.

The windows follow current UK survey guidance and are indicative starting points, not a substitute for a project ecologist, who confirms the exact methods, number of visits and the practical deadline to commission each survey for your site and season.

Bats: Collins, J. (ed.), Bat Surveys for Professional Ecologists: Good Practice Guidelines, 4th edition (Bat Conservation Trust, 2023); Natural England bat standing advice.
Great crested newts: Great Crested Newt Mitigation Guidelines (English Nature); eDNA survey protocol, Biggs et al. (2014, Natural England); NatureSpace district level licensing guidance.
Reptiles: Froglife, Reptile Survey (Advice Sheet 10); Natural England reptile survey guidance.
Hazel dormouse: Bright, Morris and Mitchell-Jones, The Dormouse Conservation Handbook, 2nd edition (English Nature / PTES, 2006).
Breeding birds: BTO Breeding Bird Survey methodology; Gilbert, Gibbons and Evans, Bird Monitoring Methods (RSPB / BTO).
Preliminary Ecological Appraisal: CIEEM, Guidelines for Preliminary Ecological Appraisal; JNCC Handbook for Phase 1 Habitat Survey.

Overarching professional standards are set by the Chartered Institute of Ecology and Environmental Management (CIEEM). Guidance is periodically updated, and survey requirements are always site-specific, so confirm the current position with your project ecologist.