The case of Invasive Alien Amphibians
There are Amphibian species which, allochthonous, are in a dynamic of expansion in certain territories and are likely to be qualified as IAS.
The main objective of the DAISIE project (Delivering Alien Invasive Species in Europe) in the European continent was to make an inventory of alien invasive species that threaten European terrestrial, freshwater and marine environments.
The database identified 37 species of Amphibians that, in some parts of the continent, can be considered to have, at some point, become naturalized outside their natural range. Not all of them have an invasive character.
Many of these species do not come from very distant areas, but are already naturally present on the continent. They have however been moved and introduced into new areas, which according to the inventory protocol, are in another country of the project area.
Here is the list of species:
According to the DAISIE inventory, France is concerned by the painted frog (Discoglossus pictus), the American bullfrog (Lithobates catesbeianus), the Levant water frog (Pelophylax bedriagae but with an unknown status), the Ambrosi’s cave salamander (Speleomantes ambrosii, but this remains to be confirmed), the Italian crested newt (Triturus carnifex), and the African clawed frog (Xenopus laevis).
The Société Herpétologique de France also reports the fire belly toad (Bombina bombina), the Strinati’s cave salamander (Speleomantes strinatii) and the marsh Frog (Pelophylax ridibundus) on a large part of the territory. Johnston’s Hylode (Eleutherodactylus johnstonei) also appears naturalized in Nantes in anthropogenic environment.
It also happens for several naturally occurring species on a part of the metropolitan territory to occur sometimes also outside their natural range, while remaining on the national territory. This is the case for example of populations of Alpine newt in the Hérault department and on the Larzac plateau or the marsh frog outside the Alsace plain. The status of some isolated populations remains to be determined (e.g. the Green Toad in Franche-Comté department).
Introductions of individuals who do not a priori become acclimatized are not uncommon, as in the case of Mediterranean tree frog regularly heard in Isère department or elsewhere.
Several exotic species present in continental France are naturalized and have a dynamics of spatial expansion. The painted frog, the Italian crested newt, the marsh frog, the fire belly toad, the American bullfrog and the African clawed frog certainly increase their range.
The last two species are the subject of special attention under the LIFE CROAA.
African clawed frog are two species known in many parts of the world to be invasive alien species.