John W. Wilkinson and Peter Hill, Amphibian and Reptile Conservation Reviewed by Steve Head
Two species (grass snake and slow worm) of our six native reptiles commonly use gardens, and one other (common lizard) is regularly seen in some. While everyone welcomes hedgehogs, birds and butterflies, some people have mixed or even strongly negative feelings about reptiles. The truth is that the species that may live in your garden are completely harmless and even beneficial for gardeners, but as a species, we humans seem to have an innate fear of snakes - probably for good reason since we evolved in Africa where many snakes are very dangerous.
Reptiles are secretive in gardens, and much harder to spot than amphibians. They are cold-blooded, but attempt to keep their temperature above ambient by behavioural strategies including sunbathing. Reptiles love sources of heat, such as compost heaps, and can also be seen basking in the sun on rocks, bare ground or short grass.
Almost any kind of compost heap will be used by these species but the attractiveness of a heap can be improved by
• choosing a sunny, south-facing spot
• making your heap or bin accessible by using traditional construction (e.g. wooden palettes or slats with easy
access) if you can
• keen composters can have two or more heaps so that there is always one available to which any reptile residents
can be transferred when you want to use the compost
• place an old mat or section of carpet on top of the heap to provide extra cover – and use it to gently view the
reptiles using the heap.
A good way to locate them is to put down small (c1m2) sheets of corrugated iron which give protection, and rapidly warm up in the sun. When you carefully raise the sheet, the reptiles are revealed - until they skitter away.
Grass snakes Natrix helvetica
As of 2017, a genetic study established that the grass snakes found in Britain should be classified as a separate species N. helvetica
, previously considered only a sub species (Natrix natrix helvetica
) of the European population. It is suggested that the barred grass snake N. helvetica differs from N. natrix
in that the body colour is grey rather than olive green, and it lacks the bright yellow collar. The British snakes sampled in the study all classified genetically as N. helvetica,
but the colour of many British examples (as below) appear to correspond to that of the nominal N. natrix,
so colour seems unreliable to distinguish the two.