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Reptile scoping survey
An initial reptile scoping survey is generally carried out as part of a Preliminary Ecological Appraisal. A desk top study is carried out to obtain any records of reptiles close to site, with a field survey undertaken to ascertain whether habitats upon a site or in the immediate surrounding area have the potential to support reptiles. This includes recording habitat structure and connectivity and the availability of a mosaic of different habitats to support basking, foraging and commuting reptiles e.g. tussocky grassland, ponds, woodland fringe and hedgerows.
This scoping survey can be carried out at any time of year, however further surveys may be required to identify reptiles species present and key habitat areas or where significant impacts from a proposed development or an activity are anticipated.
Reptile presence/absence survey
Should a site have potential to accommodate reptiles, a reptile presence/absence survey may be required to determine species present and their distribution across the site. This involves the placement of artificial reptile refugia across the site in areas considered suitable for reptiles. These refugia are made out of material that warms up quickly in the sun e.g. roofing felt or corrugated metal sheeting. Over time reptiles are attract to these refugia to bask on or under to increase or maintain their body temperature.
The refugia are checked at intervals during suitable weather conditions on several site visits to identify any reptiles present or any evidence of reptile presence e.g. shedded skins.
Reptile population survey
If reptiles are identified as present on a site then additional site visits to check refugia may be necessary to establish a population size class estimate and map out 'hot spots' of reptile activity on site.
Should the reptile population be significant, a mark-recapture survey may be required to establish a more precise population estimate. This involves capturing the reptiles e.g. via bucket traps, recording identifying features (for example by photographing the head pattern of adders) and then releasing the animals. The reptiles are then recaptured at a later date and, by comparing the individuals in the original sample to those re-captured, statistical analysis to obtain a population size is possible.
Timing of surveys
- Reptile scoping survey - can be carried out at any time of year and may be undertaken as part of a Preliminary Ecological Appraisal;
- Presence/absence reptile surveys – March to October inclusive, although the best months to detect presence are generally March to June and in September;
- Reptile population surveys – these generally have the same survey timings as presence/absence surveys.
Mitigation and licencing
Mitigation for reptiles may involve sensitive clearance of a site proposed for works, including strimming vegetation down low to encourage reptiles out of the working area. Specialist reptile fencing can sometimes be used to stop reptiles from moving back into a cleared area. For large areas, it may be necessary to trap and translocate reptiles off site to another receptor site that has suitable habitat or that has been enhanced to support reptiles.
If works will negatively affect sand lizards or smooth snake then a European Protected Species Licence (EPSL) will likely be needed due to the strict legislation protecting these species. For the other much more common UK reptile species e.g. common lizard, grass snake, slow worm and adder, an unlicensed method statement will usually suffice.
Legislation
Common lizard, slow worm, adder and grass snake are afforded protection under Schedule 5 of the 1981 Wildlife and Countryside Act (WCA) (as amended) making it illegal to kill or injure these animals.
Sand lizard and smooth snake are protected under the WCA 1981 (as amended) and the Conservation of Habitats and Species Regulations 2017, making it illegal to kill, injure, capture, disturb or handle these animals. Areas they use for shelter, resting, breeding and protection are also protected from being damaged or destroyed and it is also illegal to obstruct these animals from using these areas.
Note
The above information is based on standard guidelines and current UK legislation. Every site is unique so please contact a Torc Ecology consultant who will advise on the best survey approach in relation to the project requirements.
Facts about reptiles!
The UK is at the northern edge of the range for reptiles. This is because they are unable to regulate their own body temperature (being cold blooded) and must therefore get their warmth from the sun and immediate surroundings. In winter in the UK it is too cold for them to function and they go into brumation. This is not true hibernation, but a dormant state. Other adaptations to our cool climate include changes to reproduction; of the 6 UK reptile species only grass snake and sand lizard lay eggs; slow worm, common lizard, adder and smooth snake hold eggs inside their body until they hatch and give birth to live young.
There are four 'common' native UK reptile species: two snakes (grass snake and adder) and two lizards (common lizard and slow worm). Often mistaken for a snake, slow worm are actually a legless lizard. Habitat preferences differ between the species, with grass snake preferring damper habitats whilst common lizard and adder prefer more open sunny habitats. Slow worm get most of their body heat from surrounding habitat and are often found in garden-like habitats under compost heaps.
There are also two rare UK reptiles: smooth snake and sand lizard. These species are restricted to very small areas of heathland in Surrey, Dorset and/or Hampshire, although sand lizard is also present within the sand dunes on Merseyside.
