how to carry out a reptile survey

Why would I need a reptile survey?

Reptile surveys can sometimes be recommended by Planning Authorities before planning permission is granted for a development. This is normally if land that is proposed for development contains suitable reptile habitat that may be affected. Some people are quite surprised to think that they may have reptiles on their land and may even be surprised to hear that we have reptiles in the UK at all!

In fact, in the UK, we have six native reptile species.

Three types of snake; adder, grass snake and smooth snake and three types of lizard; common lizard, sand lizard and slow worms (often mistaken for snakes).

All of these species are protected from killing and injury under the Wildlife and Countryside Act (1981). Smooth snakes and sand lizards also have legislation protecting their habitat due to the rarity of these species within the UK.

This legislation means that clearance of ground vegetation will often require reptile surveys to be completed beforehand to establish whether reptiles are present or not. Without this knowledge, you may end up killing or injuring animals as part of the proposed development and breaching wildlife legislation.

Reptile habitat varies from species to species but most reptiles will be found in overgrown grasslands, areas of scrub, commons, heaths and moorland. Piles of rubble, stone, logs or vegetation can also provide good quality habitat and refuge space for reptiles and removal of these types of structures must be carefully considered.

Grass snake on Acorn Ecology reptile survey

Carrying out a survey

Surveying an area of land for reptiles normally consists of an ecologist placing reptile ‘refugia’ in the form of bitumen roof felt tiles or corrugated iron sheeting around 50 to 100cm2. The refugia will be spread around the site, a few metres away from each other and will be in locations that are attractive to reptiles such as close to hedges, areas of scrub, piles of cut grass or stone walls. Once deployed within the site, the refugia will be left to ‘bed in’ for around two weeks. This will allow reptiles time to find the refugia and start using it. After around two weeks, surveys will begin.

Surveys should be carried out in dry conditions with temperatures being between 9°C and 18°C. As the materials used in reptile refugia are excellent heat conductors, when left in the sun or warm conditions, they become warm to the touch. As reptiles are ectothermic or ‘cold blooded’, they cannot produce their own body heat but rely on environmental heat sources for warmth. The refugia provides an excellent place to ‘bask’ or warm up and provide energy for these animals. This is why it is important to carry out these surveys in the correct temperatures and conditions. If it is too cold then the refugia will not heat up enough to provided warmth for reptiles and if it is too hot then reptiles will already have heated up from the ambient temperature and will not need to see out other sources of heat.

During each survey, each piece of refugia will be quietly approached by an ecologist who will assess to see if any reptiles are basking on top of the refugia. The refugia will also be gently lifted to see if any reptiles are underneath. This will be repeated on seven occasions. Surveys are generally carried out once a day or every other day but can be carried out as much as two times a day as long as they are spread out by a few hours and weather conditions are suitable for both surveys. During each survey, the species, number of individuals, age class, the sex (where possible), and the location of any reptiles found will be recorded. At the end of the surveys, you will have an assessment of whether reptiles are present or absent in the site and if present, an indication of species and population numbers.

What happens if reptiles are present?

If reptiles are present on your land then further consideration will be required. This will vary case by case and may involve carrying out certain works in the winter or having an ecologist oversee certain activities to assess for reptiles. Parts of the development may even need to be reassessed to prevent harm to wildlife. Whatever the scenario, at Acorn Ecology, all of our ecologist are experienced in carrying out reptile surveys. If you believe that you are in need of a survey then contact us today for advice.

Learn more about reptiles.

Spring and autumn are the best months to survey for reptiles. Get in touch with your nearest branch today.

The best choice for your wildlife surveys

Exeter: 01392 366512

Bristol: Tel: 0117 923 2768 / Mobile: 07971 994324

London & Sout East: Tel: 01372 602372 / Mobile: 07443 652988

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