Six species of reptile - three snakes and three lizards - are native to Britain. Grass Snake, Adder, Slow Worm and Common Lizard are widespread and found throughout England, while the Sand Lizard and Smooth Snake have a much more restricted distribution. Over the last 50 years, many areas that used to be home to reptiles have been lost to development, agriculture and forestry.
Reptile presence or absence surveys are undertaken during the months of highest activity, April/May and September, when there is adequate sun but the nights are cool enough to require basking during the day. The optimum season is spring when there is an increase in mating activity. The best times of day are 0900 to 1100, and 1600 to 1900, when reptiles are most likely to be basking in open locations. The survey guidelines insist on at least seven visits during the specified active periods.
All native reptiles are listed on schedule 5 of the Wildlife and Countryside Act 1981 and are afforded different levels of protection. This act makes it illegal to intentionally kill or injure these species. Sand lizard and smooth snake receive further protection through being listed under Appendix II of the Bern Convention, Annex IVa of the EC Habitats Directive, Schedule 5 of the Wildlife and Countryside Act 1981, and Schedule 2 of the Conservation Regulations 1994.