Tortuga Gazette 28(9): 1-3, September 1992

Observations of Testudo (graeca) ibera in Lycia, Turkey

by Andy C. Highfield

The most populous and widely distributed species of Mediterranean tortoises is Testudo (graeca) ibera Pallas 1814, which occurs from the Republic of Georgia, Bulgaria, North-eastern Greece, throughout Turkey (with the exception of the Black Sea coast), Iran, Syria, Iraq and Jordan. A single specimen has been recorded in Northern Israel. Although Robert Mertens in his 1946 paper considered Testudo ibera a subspecies of the North African T. graeca this was on the basis of a small number of specimens (23 in all, 13 ibera and 10 miscellaneous North African 'graeca' complex). This author takes the view that Mertens' hypothesis is invalid on a number of grounds and that Testudo ibera* is a full and biologically separate species from the North African graeca - as indeed it was so designated when first described and named by Pallas in 1814.

Specimens of ibera from higher altitudes tend to exhibit melanistic scute markings, often with a complete absence of the central areola and anterior banding typical of the species. On occasions, entirely black specimens are found. This can be an effect of age, but self-evidently young melanistic animals are frequently encountered in some locations. In the extreme south of Turkey, in the hills of Antakya (Antioch) and extending into Syria (Aleppo), brightly marked yellow colored specimens are commonly seen. The areas where these tortoises occur are typically extremely hot in summer, and it may be that the differences in coloration noted assist the animal in thermal regulation, preventing overheating. By comparison, tortoises from high altitudes, where temperatures are lower, may find that their dark coloration is a more efficient heat absorber for basking purposes. On the topic of color, it is worth noting that some populations include individuals of differing shades - from normal to very dark. It should also be noted that juveniles are almost always more brightly colored than adults within the same population.

Basoglu and Baran (1977) have suggested that intergrades between T. (graeca) ibera and T. graeca terrestris occur in Turkey. I examined tortoises at one site where these supposed intergrades occur, the coastal town of Kas. This is an interesting site, in that it consists of a low lying isthmus and lagoon area, backed up by steep and impenetrable cliffs on all sides. The ground is extremely rocky and consists mostly of loose scree covered by coarse and thorny shrubs including gorse and Kermes oak. Finding tortoises in these conditions is far from easy (and frequently painful!). However, a young adult female and well-worn elderly male were eventually located and photographed. In terms of their coloration and markings, both conformed to that typical of T. ibera. There was no evidence of anything unusual at all, other than noting that the adult male was smaller than would be expected given his evident great age (160 mm SCL). This could, however, very easily be attributed to the generally poor food availability in this spartan and arid location. Certainly, this is an inhospitable place for tortoises, and I would estimate the population density in the few remaining undeveloped areas of the bay to be very low.

The average size of adult female T. ibera is about 200 mm SCL, while males are smaller at about 180 mm SCL. In Lycia recently (Fethiye), I encountered one enormous female measuring 290 mm SCL, and two others one measuring 270 mm SCL and one of 280 mm SCL. Large males measuring up to 235 mm SCL were also encountered in this locality. Out of 112 animals recorded during a 1 week survey of the region only 6 exceeded 250 mm SCL and all were female. Most of the larger animals exhibited obvious signs of considerable age, being very battered and worn. One interesting discovery was that of 3 specimens which exhibited divided supracaudal scutes. Previously, this had only been observed in captive specimens (Highfield, 1989).

In the surrounding mountains (Ak Ben Yala), a nesting female was observed at an altitude of 1350 m on an overcast and somewhat cool day. This particular study site is a summer pasture, surrounded by peaks on all sides, but itself gently sloping and lightly populated by a Kermes oak shrubs (Quercus coccifera) which with their sharp, spiny leaves are much favored by the tortoises for constructing their overnight scrapes beneath. From these scrapes, which are used by several tortoises alternately, very clear 'tortoise trails' can frequently been seen in the surrounding vegetation. The natural food plants of this tortoise, which is an exclusive herbivore, include vetches, dandelions, mallows, and numerous species of the Leguminosae family.

In coastal Turkey during spring, daytime activity typically begins at 8:30-9:30 a.m. when tortoises emerge from their overnight scrapes. Depending upon prevailing weather conditions, the next hour or so is spent basking. This is often accomplished by the tortoise bracing at an angle against a convenient rock. During basking the legs and head are typically fully extended to increase the area of exposure to the sun. Most tortoises bask within a 1 meter radius of their overnight scrape. By 10:30 a.m. most tortoises are actively grazing, an activity which continues intermittently until about 7:00 pm. In the heat of summer, mid-day activity is much reduced however. From about 8:00 pm. tortoises are beginning to return to their overnight scrapes, but on dull and cold days this may occur much earlier. The same scrape is not necessarily used each night by an individual, tortoises apparently using whatever existing scrapes happen to be closest to their grazing area at close of day or creating a new one. Most of the scrapes I observed were well used, suggesting that the same scrape is used by several tortoises in succession. This was confirmed by carefully monitoring specific scrapes over several days. This behavior pattern is fairly typical of tortoises throughout the country, but the precise times of day of rising and retiring do vary considerably with altitude, weather and season.

The eggs of T. ibera are large compared to those of North African T. graeca and are oval rather than spherical. Each egg typically measures some 36 x 30 mm and clutch density is typically 6-8, although large females may produce 12 or more eggs. The hatchlings measure about 33 mm in length and weigh approximately 13 g. Eggs are laid from May-June and the first hatchlings usually emerge with the beginning of the autumn rains in August-September. By October-November both adults and hatchlings are entering hibernation. Tortoises dig in for hibernation under large rocks, or under the same shrubs employed for overnight scrapes.

In the ruins of the Lycean cities of Xanthos and Kaunos many tortoises were encountered where they were generally well hidden amid the ancient stones and were effectively invisible to all but the most eagle-eyed of tourists. The ordinary Turkish people tend to look somewhat kindly on tortoises, considering it extremely bad luck to kill one. Road traffic does account for some mortalities, but many drivers do seem to take avoiding action. Wandering tortoises are not considered as agricultural pests, but rather as harbingers of good luck and fecundity to the land. Turkey almost certainly has one of the largest and most secure tortoise populations of any Mediterranean country, and I was especially encouraged to find a healthy number of both juveniles and animals of extreme old age. This is an excellent indicator that Testudo ibera in Turkey is not under any immediate threat - a very different picture from that which I have encountered in North Africa, where isolated and fragmented populations of tortoises are struggling hard to survive massive habitat destruction and the devastating effects of 50 years of large-scale trade collecting, only recently ceased.

References

Basoglu, M. & Baran, I. (1977) The Reptiles of Turkey. 1. The turtles and lizards. Bornova-Izmir: Universitesi fen fakultesi kitaplar.
Eiselt, J. & Spitzenberger, F. (1967) Ergebnisse zoologischer Sammelreisen in der Turkei: Testudines. Ann. Nathist. Mus. Wien. 70: 357-378.
Eiselt, J. (1967) Bericht uber eine dritte zoologische Sammelreise in der Turkei, April bit Juni 1966. Ann. Nathist. Mus. Wien. 70: 293-300.
Herrn, C. (1966) Testudo graeca terrestris Forskal nue fur die Turkei. Stuttgarter Beitr. Naturk. No. 155.
Highfield, A. C. (1989) Taxonomic diagnostic characters of Tortoises (1): Observations on the taxonomic significance of the division of the supracaudal scute in Testudo. British Herpetological Soc. Bull. 30:14-18.
Mertens, R. (1946) Uber einige mediterrane Schildkroten-Rassen. Senckenbergiana Frankfurt 27: 111-118.
Werner, F. (1903) Uber Reptilien und Batarachier aus West-Asien (Anatolien und Persien). Zool. Jarb. Syst. Jena. 19: 329-346.

*Editor's note: Andy Highfield, author of "Keeping and Breeding Tortoises in Captivity", is Director of Britain's Tortoise Trust. Mediterranean tortoise taxonomy is controversial, many experts still consider ibera a sub-species of T. graeca.