The Bufo genus has approximately 100 species which live on five continents (Europe, Asia, Africa, North and South America). Only three species of this genus live in Europe, namely Bufo bufo, Bufo viridis and Bufo calamita. Only two of these species can be found in Romania: Bufo bufo and Bufo viridis [5, 6]. Recent research have reached the conclusion that Bufo viridis belongs to the Epidalea genus [10, 11, 13, 12, 15], but this is not fully established and so the species can still be treated as it was initially listed.

Bufo bufo covers a wide range being found in North-West Africa, temperate Europe and Asia up to Sakhalin Island and even Japan. It can reach the altitude of 2200 meters in the Alps and even 3000 meters in Tibet [5, 6].

In Romania this species can be found between the altitudes of 0 and 2000 meters, mainly in the central and north western regions of the country [3, 5, 6].

Morphology. It has a broad and squat body. Its eyeball is horizontal and the snout is short and round. The fingers of the fore limbs are relatively short and round, the third finger being the longest; the hind legs have medium length (pulled near the body it can reach the ear drum together with the tibio-tarsian joint) and medium sized flat fingers. The skin on the back is covered with wart-like lumps of different sizes which can be spiny or porous and eliminate an irritant secretion. Two large, bulging glands, named parotoids can be observed behind the eyes. The skin on the abdomen is granular and the grains can sometimes have horny spines. Males are much smaller than females, but their fore limbs and their fingers are very well developed and powerful. This species lacks vocal sacs. During the reproduction time males develop some dark coloured tubercles on the fingers of the fore limbs, called nuptial pads. These are used by the males to grasp the females when mating because the females cover large distances to the mating ponds carrying the males on their backs [5, 6].

Colour. The colour varies from greyish-brown, red-brown, dark brown to olive-brown with different spots on the back and dirty white to greyish-brown on the underside. The colour of the iris varies from golden to copper red [5, 6].

Ecology. The common toad is a terrestrial species found both in uninhabited areas and in cultivated regions, from forests, fields, gardens to hills and mountains. During the day it stays hidden in underground galleries made by rodents or by themselves, in rock holes, under stones, tree trunks, under leaves or bushes [5, 6].

It usually becomes active and begins to look for food at dusk or when the flank where it lives is no longer exposed to the sun. Some individuals can also be found feeding late at night.  During the reproduction season, during the juvenile stage or when it rains and the sun is covered by clouds the toad has a daytime activity [5, 6].

It feeds on invertebrates, insects, centipedes, spiders, snails, earth worms and bugs. Having a broad and squat body it moves slowly, it crawls and it makes short jumps [5, 6].

Reproduction. Reproduction time starts in late March or early April. In this period the toad turns into an aquatic species and becomes a very good swimmer. Males generally outnumber the females and they never leave females before spawning. They lay small black eggs on the aquatic plant stalks, near the shore. The eggs look like long and fine gelatinous strings disposed on 2-4 rows. Such a string can even measure 7 meters in length and it can contain approximately 6000 eggs. Young larvae, also known as tadpoles are black and they develop in 2-3 months [5, 6].

Legislation. In Romania the species is protected by Law 13 of 1993 by which Romania ratifies the Berne Convention (Annex III), by Law no. 57/2007 regarding the state of natural protected areas, the conservation of natural habitats, of the wild flora and fauna (Annex III) and by Government Emergency Ordinance no. 57/2007 regarding the state of natural protected areas, the conservation of natural habitats, of the wild fauna and flora, approved with the subsequent amendments and supplements, being considered a species of national interest which needs strict protection (Annex IV B) [16, 17, 18].

According to the IUCN classification the species has a statute of low concern at global level (LC) while in the Red Book of the Vertebrates in Romania the species is nearly endangered with extinction [9, 19].

References

1. Baillie J.E.M., Hilton-Taylor C., Stuart S.N., (2004): A Global Species Assessment, IUCN Red List of Threatened Species.

2. Cogălniceanu D., Aioanei F., Bogdan M., (2000): Amfibienii din România, Determinator. Editura Ars Docendi, Bucureşti.

3. Cogălniceanu D., Szekely P., Samoilă C., Iosif R., Tudor M., Plăiaşu R., Stănescu F., Rozylowicz  L., (2013): Diversity and distribution of amphibians in Romania, Zookeys 296:25-57.

4. Covaciu-Marcov S.D., Ghira I., Cicort-Lucaciu Al. Şt.,  Strugariu Al., Bogdan H.V., (2006): Contributions to knowledge regarding the geographical distribution of the herpetofauna of Dobrudja, Romania, North-Western Jurnal of Zoology, Vol. 2, No. 2: 88-125.

5. Fuhn  I. E.  (1960):  Amphibia. In: Fauna  R.P.R.,  Vol.  XIV,  Fasc.  1, Ed.  Academiei R.P.R., Bucureşti. [in Ro]

6. Fuhn, I.E. (1969): Broaște, șerpi, șopârle. Ed. Ştiinţifică, Bucureşti.[in Ro]

7. Gasc J.P., Cabela A., Crnobrnja-Isailovic, Domen D., Groessenbacher K., Haffner P., Lescure J., Martens H., Marinez Rica J.P., Maurin H., Oliveira M.E., Sofianidou T.S., Veith M., Zuiderwijk A., (1997): Atlas of Amphibians and Reptiles in Europe. Societas Europaea Herpetologica & Museum National d’Histoire Naturelle Paris.

8. Ghira I., Venczel M., Covaciu-Marcov S.D., Mara G., Ghile P., Hartel T., Torok Z., Farkas L., Racz T., Farkas Z., Brad T., (2002): Mapping of Transylvanian herpetofauna. Nymphaea Folia naturae Bihariae 29: 145–201.

9. Iftime A., (2005): Reptilia. In: Botnariuc & Tatole (eds): Cartea Roşie a Vertebratelor din România, Ed. Acad. Române, București.[in Ro]

10. Litvinchuk S.N., Rozanov Yu.M., Usmanova N.M., Borkin L. Ya., Mazanaeva L.F., Kazakov V.I., (2007): Variability of Microsatellites BM224 and Bcal7 in Populations of Green Toads (Bufo viridis Complex) Differing by Nuclear DNA Content and Ploidy. Cell and Tissue Biology 1(1): 65-79.

11. Sos T., (2008): Review of recent taxonomic and nomenclatural changes in European Amphibia and Reptilia related to Romanian herpetofauna, Herpetologica Romanica, Vol. 2: 61-91.

12. Speybroek J., Crochet P.A., (2007): Species list for the European herpetofauna – a tentative update. Podarcis 8 (1/2): 8-34.

13. Stöck M., Moritz C., Hickerson M., Frynta D., Dujsebayeva T., Eremchenko V., Macey J.R., Papenfuss T. J., Wake D.B., (2006): Evolution of mitochondrial relationships and biogeography of Palearctic green toads (Bufo viridis subgroup) with insights in their genomic plasticity. Molecular Phylogenetics and Evolution 41: 663-689.

14. Strugariu A., Sos T., Gherghel I., Ghira I., Sahlean T.C., Pușcașu C.M., Huțuleac-Volosciuc M.V., (2008): Distributions and current status of the herpetofauna from Măcin Mountains Area (Tulcea County, Romania), Analele Științifice ale Universității “Al. I. Cuza” Iași, s. Biologie animală, Tom LIV.

15. Vences M., (2007): The Amphibian Tree of Life: Ideologie, Chaos oder biologische Realität? Zeitschrift für Feldherpetologie 14: 153–162.

16. ***Legea 13 din 1993 prin care România ratifică Convenţia de la Berna.[in Ro]

17. ***Legea nr. 462/2001 privind regimul ariilor naturale protejate, conservarea habitatelor naturale, a florei şi faunei sălbatice.[in Ro]

18. ***Ordonanţa de Urgenţă a Guvernului nr. 57/2007 privind regimul ariilor naturale protejate, conservarea habitatelor naturale, a florei şi faunei sălbatice, aprobată cu modificări şi completări ulterioare.[in Ro]

19. *** www.iucnredlist.org