ABSTRACT

The present status of tortoises (Testudo spp.) in Greece is described, based on studies from 1975 to 1986. The survey includes 79 single species populations at 42 sites throughout the country, at which about 9,600 individuals have been marked and released. Tortoises were still common in Greece in 1986. However, 28 per cent of populations are immediately threatened by catastrophic decline, and 39 per cent have declined in the recent past or are liable to long-term decline. The remaining 33 per cent are not apparently threatened at present. There was no significant difference in these proportions between dense and sparse populations, or between the three species. Most of the highly threatened sites were near the coast; many of the sites under no apparent threat were in mountainous areas. Threats included habitat loss to cultivation or building, fires started for pasture improvement or by accident, herbicide spraying, agricultural machinery, and direct predation of tortoises or nests by rats near rubbish dumps. Most (61 per cent) of the threats to sites were associated with agriculture.

Testudo hermanni is the most widespread and common species, found in woods, scrub, heath, grassland, and farmland. There was substantial variation of body size between populations, which was apparently at least partly genetic; a range of sites would need to be protected to preserve this variability. Populations in the south are in danger, but overall this species is not threatened in Greece. Testudo marginata is widespread in Greece, where it is endemic; its typical habitat is thorny scrub. Only one out of 23 populations of this species was found at high density; we recommend protection for this site (at Gytheion). Testudo marginata is the largest and latest-maturing species, with the lowest proportion of juveniles in the total marked sample. It is particularly vulnerable to slow decline from occasional loss of adults, such as those killed by machinery while foraging in cultivated areas, or casual collection. Testudo graeca is restricted to north eastern Greece, where it usually occupies coastal habitats which are most likely to be disturbed. It is the most threatened species in Greece, but is widely distributed elsewhere.

The reptile faunas associated with tortoises are described, to evaluate the 'biogenetic reserve' concept for reptiles in Greece. Three quarters of the 33 native species of lizards and snakes in mainland Greece have been found with tortoises. In addition, tortoises may be found in very disturbed areas, and they may be affected by factors which affect them but not other reptiles. The presence of tortoises therefore cannot be used as an indication of a particular reptile community, or of an area of high reptile species richness. The herpetofauna of the Alyki coastal heathland is described in detail. We suggest that Alyki merits protection as an unexploited coastal heathland containing almost all the reptile species likely to be found in that habitat. Larger reserves may contain more species, but will not be as effective in conservation if they simply contain the most common species inhabiting many different habitats.