Guidance

Reptiles: surveys and mitigation for development projects

Standing advice for local planning authorities who need to assess the impacts of development on reptiles.

Survey reports and mitigation plans are required for development projects that could affect protected species, as part of getting planning permission or a mitigation licence. Surveys need to show whether protected species are present in the area or nearby, and how they use the site. Mitigation plans show how you’ll avoid, reduce or manage any negative effects to protected species.

This is Natural England’s standing advice for local planning authorities who need to assess planning applications that affect reptiles. These include smooth snakes and sand lizards, which are European protected species, and these species which are protected by UK law:

  • adder
  • grass snake
  • common lizard
  • slow worm

This information can be used to decide what is needed for surveys and planning mitigation measures for reptiles.

Ecologists need to decide which survey and mitigation methods are right for the project being worked on. If this standing advice can’t be followed, they’ll have to include a statement with the planning or licence application explaining why.

Where this guide says ‘you’ it means the applicant or their ecologist.

Get more detail on:

Decide if you need to survey

You must be suitably experienced, eg a qualified ecologist, and licensed to survey for reptiles. Survey for reptiles if the development:

  • site has habitat suitable for reptiles
  • will alter the water levels of the site or surrounding area
  • will break apart suitable habitat for reptiles
  • distribution and historical records suggest they may be present

Survey methods

Acceptable methods for surveying most reptiles are:

  • searching for basking animals on banks, piles of wood and edges of woodland
  • laying out artificial refuges like corrugated iron sheets (this is the only method recommended for slow worms and smooth snakes)
  • carpet tiles or roofing felt bedded down well into the vegetation

Survey for reptiles in April, May and September. Avoid July to August and November to February.

Combine daytime searches with artificial refuges, and look at hibernation sites as well as summer sites.

Look at suitable habitat within the home range of (the distance the animal normally travels from) the development site. Surveys should aim to establish the population size and distribution of reptiles on and near the development site.

Assess the impacts

Assess the impacts this development would have on reptiles if no mitigation measures were planned. Impacts to consider include:

  • losing links between habitats
  • separating summer and hibernation sites
  • reduction in habitat quality
  • risk of fire
  • effect of increased litter

Avoidance, mitigation and compensation methods

Address the potential impacts you’ve identified on reptiles with your mitigation plans.

For reptiles, mitigation planning should include:

  • consider changing the layout and not developing the areas used by reptiles
  • displace them from sensitive areas by changing the vegetation
  • changing the timing of the work
  • move the reptiles (translocate) to another area that has been specially prepared, but only as a last resort, maintaining networks across the site (for large schemes)

Compensation methods can include:

  • creating links to other habitats
  • creating new habitat
  • improving existing habitat

Temporary fencing for mitigation

You can use fencing to prevent reptiles moving into areas where there are damaging activities. Make sure the reptiles can’t pass over, under or through the fencing, eg by keeping vegetation close to the fence short on both sides.

Moving reptiles (translocation) as mitigation

If you need to move reptiles to a new location you’ll have to choose a receptor site:

  • as close as possible to the development site, and within the same local planning authority if possible
  • that is at least the same size as the habitat that will be lost, and larger if the habitat to be lost is high quality (you can provide smaller habitat if it’s substantially better quality)
  • that will serve the same function as the habitat to be lost, eg it has hibernation features
  • with similar habitat to the area that will be lost, including water bodies
  • that doesn’t currently support the same species, but can be improved to make it suitable
  • that will be safe from future development and managed in the long term

You can introduce small numbers of reptiles to an area with an existing population if you have improved the habitat so it can support the increased numbers.

You must allow enough time for new habitats to become suitable for the reptiles before you start to capture them.

Capture methods for mitigation

You can:

  • use artificial refuges (but capture legged lizards by hand or noose)
  • gradually reduce the amount of suitable habitat to concentrate the reptiles in certain areas, making it easier to capture them eg by strimming rough grass
  • dismantle rubble, rock and wood piles carefully by hand to capture any reptiles using them as refuges

Only use invasive methods like mechanical excavation under expert supervision and after exhausting other methods.

Allow enough time to capture and release the reptiles, and build this into the development plans. For large populations, this can take up to 3 years, capturing between March and September. For small populations, 1 year is usually enough. Try to capture reptiles early in the season to avoid problems before hibernation or increased numbers due to breeding.

Don’t capture reptiles:

  • that are heavily gravid (pregnant or egg-laden, usually found in early summer)
  • during autumn
  • that are hibernating
  • in extreme weather (heat, drought, flooding)
Published 13 October 2014
Last updated 28 March 2015 + show all updates
  1. Information updated by Natural England experts.
  2. The links for more detail on surveys and mitigation are now higher up in the guide.
  3. First published.