Amphibia: ANURA (Frogs & Toads)

We recorded five species of anurans (tailless amphibians ie. frogs and toads) from four families, and managed to photograph four of these species.


Bufo bufo spinosus - Mediterranean toad
A relatively large species (100-180 mm) and one of the most instantly recognisable and frequently encountered amphibians in Europe, but the Mediterranean toad (Bufo bufo spinosus) was not found to be as the more ubiqitous Green toad (Pseudoepidalea viridis) On the Evros River. We only found a single specimen near Loutrós, but it was a large specimen, the largest amphibian encountered on the trip, even before it puffed itself up in defence. This Mediterranean subspecies reputedly possess more spinous skins than the nominate subspecies from much of Europe, but our specimen was not especially spinous.

Mediterranean toad,
Bufo bufo spinosus

large specimen from Evros River near Loutrós

Pseudepidalea viridis - Green toad
The commonest toad encountered, the Green toad (Pseudepidalea viridis) is a central and eastern European amphibian, slightly smaller than the aforementioned species (100-120 mm), which we encounted in some numbers in the Evros River near Loutrós. Easily identified by its bold patterning, some specimens were much more vividly marked than others.

Green toad,
Pseudepidalea viridis

subdued and vividly marked specimens from near Loutrós



Bombina variegata scabra -Balkan yellow-bellied toad
We only found a single specimen of this small amphibian (<50 mm), in a shallow creek near Passáni to the north of Loutrós. All six species in genus Bombina are small knobbly toads with cryptic dorsal patterning and brightly coloured (red or yellow) undersides. Should the little toad feel threatened it will either roll on its back to show the bright colour beneath or adopt a pose known as the "unkenreflex" which involves arching the back, covering the eyes with the forelimbs and again exposing the aposematic bright flashes from below.

Balkan yellow-bellied toad,
Bombina variegata scabra

a single specimen was found in a creek near Passani to the north of Loutrós
The exposure of the aposematic yellow belly is a defence meant to warn off a potential predator A defence known as the 'unken reflex' which exposes the apostematic bright pattern of the undersides



Hyla arborea - European treefrog
We found a single specimen of European treefrog (Hyla arborea) (< 50 mm) on a tree overhanging a small pond inhabited by large numbers of Marsh frogs (Pelophylas ridibundus) to the north of Loutrós, on an our second day and one the day after heavy rain. Unfortunately this specimen was not photographed and return visits to the pool failed to result in any further specimens.



Pelophylax ridibundus - Common marsh frog
Probably the commonest amphibian encountered, the Common marsh frog (Pelophylax ridibundus) was found in every sizeable watercourse visited, from the pond north of Loutrós to the Evros River and associated wetlands. One specimen was even found perched in a tree 1.5 m from the ground. At night its call of this large frog (100-150 mm) was everywhere but we did not find this species in the smaller, more upland, creek up near Passáni. A second species, the Levant marsh frog (P. bedriagae) also occurs in this part of Thrace, in sympatry with the Marsh frog, and some of the specimens encountered may belong to this species, while a third species, the Balkan marsh frog (P. kurtmuelleri) is also present in western Thrace. Patterning and colouration is variable with these species being difficult to separate without sonograph recordings of their calls or comparison of their electophoretic alleles.

Common marsh frog,
Pelophylax ridibundus

a variety of differently patterned specimens from locations around Loutrós and the Evros River