Reptiles and amphibians are related although there are some fundamental differences between them. The two are usually grouped together and are sometimes known as herptiles. I will not attempt to explain the differences as my purpose here is to help with finding and identifying them rather than understanding their biology.
The reptiles seen in Dorset, and we have all six native species plus a couple of introduced species, are restricted to snakes and lizards. Worldwide, reptiles species are numerous and much more diverse. Our British native snakes are the adder (sometimes called the viper), the grass snake and the smooth snake. Our lizard species are the slow-worm, the common lizard and the sand lizard. In addition to these native species you can also find the wall lizard and the green lizard; these are often around the sandy cliffs of Bournemouth and Boscombe.
Amphibians are restricted to two groups, newts and frogs/toads. The three species of native newts you can encounter here are the great crested, the palmate and the smooth newt. We also have the common frog, common toad and natterjack toad as native species and the introduced marsh frog. The natterjack toad and the marsh frog are very restricted in range.
Apart from the native species listed and the more well established colonies of introduced species you can encounter other oddities that have been either released or have escaped from captivity. Always expect the unexpected, especially near large human settlements! There can be exotic species of lizard seen, in some ponds there are terrapins and you may even encounter salamanders. Most escaped species do not survive long in the wild but some have thrived and can be a nuisance, especially terrapins!
Reptiles and amphibians are generally considered to be cold blooded but this is not strictly true. That said, they do not have the same mechanism for controlling their body temperature as mammals and need to use external sources of heat, usually the sun, to warm themselves and use water to cool down if they become too hot. When cool they are lethargic and inactive, when warm they can move very quickly, even snakes that have no legs!
All the animals in this group are insectivorous and some, the snakes, also feed on larger prey. Grass snakes, for example, are very fond of frogs! As a result of their diet all of these creatures spend their life on primarily on land. It is not true that amphibians only live in water; they enter water, usually still water in ponds, to breed. They also use water to cool down in hot weather (see above) and grass snakes can also be seen hunting in water for food.
Why are all six species of reptiles found in Dorset? Mainly because the Dorset heath is ideal habitat for them. The sandy soil is ideal for breeding and there is an ample food supply. The limestone cliffs of the Purbeck coast are also good places to for reptiles but they are difficult to find here as much of their range is in somewhat inaccessible places. Obviously Dorset's warm, southerly position also helps.
Amphibians can be more difficult. The best time to see newts is in spring when they are in water to breed. The rest of the year they are somewhat elusive. Frogs and toads are more usually seen in gardens than in the wild these days.
In general, all of these species are declining in Dorset (and throughout the British Isles), primarily because of habitat loss and fragmentation of breeding colonies leading to the weakening of gene pools. The heaths are prone to human disturbance through dog walking, mountain bike riding and purposely or neglectfully started fires. The rapidly declining population of insects is not helping their cause either. Some species are said to be well under half of the population levels of 50 years or so ago. Much thought and conservation effort is going in to try and reverse these trends.
There is no single place to see all of the creatures, each has its own unique niche, but by far the best place I know to see a number of them is the Dorset Wildlife Trust reserve at Higher Hyde Heath. Joining the Wednesday morning guided walk at Arne is also a good way to get familiar with some of these species.
In the field:
Based on what we know about the life style of these animals it is possible to draw some conclusions on how best to find and watch these attractive fascinating creatures:
- Find the right habitat. Most of these creatures have pretty specific requirements that determine where they live and so will limit the likely places you can find them. Finding a known site where they occur is an obviously good starting point
- Look early in the season. When they first emerge from hibernation (around March in most years) the weather is colder and they are lacking in warmth and strength and so are less able to be active. At this time of year they spend much more time basking in the sun gaining warmth.
- Look early in the day or on days when the weather is cool and cloudy. To keep active they need to keep warm and so look looking for them on a warm, sunny afternoon is probably not going to very effective. In bad weather they shelter in the safety of cover so do not look if the conditions are totally unfavourable.
- Tread carefully. These animals can detect ground vibration from your footsteps from some distance away and if they are warm they will move away long before you get to them. Even snakes can move quickly despite having no legs!
- Look for sunny spots. South facing slopes are good for lizards and snakes. Look also on fallen tree trunks, log piles, posts in the ground, any prominent feature in the sun. On cooler days look for things like tyres, tin or tiles, anything made of a material that absorbs heat as these creatures will often use them to absorb heat from.
- Look in damp or dark, cool places for frogs, toads and newts. They do not like to get too hot or their skin can dry out. In really hot weather look for them in ponds, pools in ditches. This is also where you will possibly find them in spring when they are breeding.
- Reptiles in particular are creatures of habit. Once they find a warming spot that suits them they will continue to use it unless it proves to be dangerous! If you see a lizard or snake but it detects you coming and slips away, move off for a while and come back slowly later, it may well have returned to its favoured spot again by then.
- Exercise extreme care if you lift a sheet of corrugated iron to see what is underneath. You must not harm these creatures nor should you handle them - they are protected by law! You may also find an adder in such places and, when threatened, they can bite. An adder bite is rarely fatal but I understand it can be quite unpleasant!
Just to emphasize that last point again. ALWAYS put nature first, do not do anything to harm or unduly distress any creature, even for a better view and especially for a better photograph. Do not take specimens unless you are engaged in scientific research for the benefit of the conservation of these species. If you hurt yourself it is your fault but there is no excuse for hurting a helpless or harmless creature!