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There are as many introduced amphibian and reptile species in the UK as there are native species - at least thirteen non-native species present and breeding, another eight species, or subspecies, present but not breeding (see table below).  In general, alien distribution is very localised so you are less likely to encounter them than our native species. However, some of the aquatic aliens are relatively widespread and are, therefore, more likely to be encountered.

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Key: Present and Breeding.... Present.... Status Uncertain
Species	Scientific Name
Alpine newt	(Mesotriton alpestris /Triturus alpestris)
Italian crested newt	(Triturus carnifex)
Midwife toad	(Alytes obstetricans)
African clawed toad	(Xenopus laevis)
North American bullfrog	(Lithobates catesbeianus /Rana catesbeiana)
Marsh frog	(Pelophylax ridibundus /Rana ridibunda)
Iberian water frog	(Pelophylax perezi/Rana perezi)
Edible frog	(Pelophylax kl. esculentus /Rana kl. Esculenta)
Pool frog (non-northern clade)	(Pelophylax lessonae/ Rana lessonae)
Western green lizard	(Lacerta bilineata)
Wall lizard	(Podarcis muralis)
Green lizard	(Lacerta viridis)
Aesculapian snake	(Zamenis longissimus /Elaphe longissima)
European tree frog	(Hyla arborea)
Red-eared terrapin	(Trachemys scripta elegans)
Yellowbelly slider (terrapin)	(Trachemys scripta scripta)
Cumberland slider (terrapin)	(Trachemys scripta troosti)
Fire-bellied toad	(Bombina bombina)
European pond terrapin	(Emys orbicularis)
Italian wall lizard	(Podarcis sicula)
Garter snake	(Thamnophis spp.)
Printable version available here

How did they get here?

Non-native amphibians and reptiles have reached the UK through a variety of means. Some species have been introduced out of curiosity - or in the belief that they would 'enhance' our native fauna. This practice has a long history and there are records of such introductions dating to the 19th century. Other species have arrived as stowaways. For example, the midwife toad is believed to have been imported along with plants for the nursery trade. The discovery of green/water frog populations close to fishery establishments suggests that these frogs may be hitching rides with importations of fish stocks (probably as tadpoles).

More recently, non-native species have arrived through pet keeping either as more significantly, they may arrive through pet keeping accidental escapes or as deliberate releases. For example, terrapins are usually the result of unwanted pets being 'dumped'.

It is now illegal to release non-native species into the wild.

Alien Encounters invites you to report your sightings of non-native amphibians and reptiles.  Information on most of these species is available from the left-hand menu, or the 'Animals' pages of the ARC website. 

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