Wildly spread in the past on Bulgarian territory two tortoise species Spur-thighed Tortoise (Testudo graeca Linnaeus) and Hermann’s Tortoise (Testudo hermanni Gmelin) are globally threatened nowadays, listed in Red List of International Union for Nature Conservation (IUCN-2004) and priority for conservation under international convention as well: Convention on conservation of European wild flora, fauna and natural habitats (Bern Convention); Convention on International trade with endangered wild flora and fauna species (CITES); Habitat Directive 92/43 of the European Union (1992).
According to Bulgarian legislation both species are protected under Biodiversity Conservation Act and the Penal Code of Bulgarian Republic.
Both species wildly occur at sea level up to 1400-1500m altitude but their number decrease drastically even tough being most common reptile species in the past. In 1899 Konstantin Irechek wrote:” Those who come from North will stay astonished by the numerous tortoises with domed plates, black or white-yellowish checked, two spans long, found less frequently northward of the Balkan but common in Thrace.” If nowadays the same route would be traversed there is a slim chance of coming across tortoises. Currently the highest density of tortoises is established on the territory of Eastern Rhodopes Mountain, Sakar Mountain, Derventski Vazvishenija Hills, Stranja Mountain and south Struma Valley as well as the lowlands of the ranging mountains. Their populations are quite fragmented or they have reached the population minimum.
Hermann’s Tortoise (Testudo hermanni Gmelin, 1789) is spread from the northeastern Spanish coast to Bosporus. It occurs in the southern coast of France, Italy (not including the land of the Alps and the River Po valley), the west coast of the Balkan Peninsula, Albany, Greece, Macedonia, the European part of Turkey. On the Balkans it can not be found in a wide territory of Croatia, Bosnia and Serbia as in Bulgarian and Rumanian Dobrudzha it doesn’t occur at all. On the North of Danube River it occurs in a small region of Rumania, north-east of Zheljazna Vrata Gate. It can be found at the Balearsk’ Islands, Corsica, Sardinia, Sicily, Malta and the surrounding small islands, though considered as introduced in many of these places in the remote past.
The sub-species (T. h. boettgeri Mojsisovics, 1898) occur in Bulgaria. It is distributed on the territory of the whole country, excluding Dobroudja, the highlands and mountains of west Bulgaria. In the lowlands of north Bulgaria and Thrace it became extinct due to development of modern agriculture and the common modification of the landscape. It is likely to be seen in hilly and low mountainous regions, overgrown with bushes and low, thinned out woods. In contrast to the other species, Testudo hermanii is closely connected to the forest. It is spread from the sea level up to 1400-1450m altitude. It is mainly daily active species. Its nutrition is based on herbaceous plants, windfalls, as well as mollusks and other invertebrates. It lays out two to -five eggs, two-three times. The eggs, which are white, quite oblong are buried in the earth by the tortoises on dry, sunny spots. 100 to 120 days are necessary, the eggs to be hatched.
The species winter in the crumbly soil of dry slopes, usually exposed to the South, where it digs out inclined downwards holes, 30 to 90 cm deep.
Spur-thighed Tortoise (Testudo graeca Linnaeus). This species is spread along the eastern and southern coast of Spain, Balers Islands (reintroduced in Sardinia, the Apennine Peninsula, Sicily, Malta, Crete and Peloponnesus),southeast part of the Balkan Peninsula, Malaysia, western Iran, Syria and north Iraq as well as partially along the Mediterranean coast of Morocco. On the Balkans is established in southeastern Albany (?), Macedonia, northern Greece (including some islands), the European part of Turkey, Bulgaria (excluding the northwest part, the high-hollow fields and mountains higher than 1500m altitude), and Romanian part of the Dobrudzha till the River Danube Delta.
On the Balkan Peninsula (including Bulgaria) the sub-species (T.g. ibera Pallas) occurs. It is spread from the sea-level up to 1300m altitude. It requires open spaces, covered by herbaceous vegetation. It often enters into bushes, woods, and gorges during the summer heats. This species is daily active as well and has the same variety of nutriments as Hermann’s Tortoise (Testudo hermanni). In June and July it lays out two-three times, two to eight almost round eggs with calcareous shells, which buries in sunny spots. The eggs hatch after 70 to 100 days. It is found, that the young of this species often go up to the surface next spring, wintering on the spot, where they hatched. The living cycle of Spur-thighed Tortoise (Testudo graeca) lasts 110-120 years.
In Bulgaria are found the biggest and perhaps the oldest tortoises among the species’ range.
Testudo hermanni differs with 5 narrow (mostly the second, third and forth plates, the fifth is wider) longitudinal plates at mid part of the carapace in contrast to the larger row with second, third and forth plates wider than longer of Testudo graeca (fig.1).
Testudo hermanni has two supracaudal plates and Testudo graeca – typically a single supracaudal plate (fig. 2.1.) This is not but a certain characteristic as appears individuals making exception.
Testudo hermanni has longer tale (especially male individuals) with large scale on tail tip, compared to entirely cover by small scales tail of Testudo graeca (fig. 2.2.).
Testudo graeca differs in having large conic spurs on thighs and on the cloaca, lacking by Testudo hermanni.
Beshkov Vl., K. Nanev. 2002. Amphibians and Reptiles in Bulgaria.-Pensoft, 120 p.
Boyan P. Petrov, Vladimir Beshkov, Georgi Popgeorgiev, Dimitar Plachyiski. 2003. “National Action Plan for Tortoises Conservation in Bulgaria”, Vers.1, BSPB, NMNHS-BAS, Sofia.