O. G. Dely szerk.: Vertebrata Hungarica 21. (Budapest, 1982)

Brushko, Z. K. ; Kubykin, R. A.: Horsfield's tortoise (Agrionemys horsfieldi Gray, 1844) and the ways of its rational utilization in Kazakhstan 55-62. o.

Our studies on marked animals in an area of 3 hectares at Tsingildy settlement have shown that the movement of tortoises is very much localised. Some specimens keep to one territory while others make limited excursion (max. 47 m) after which they return to their normal territory. For the majority of animals that territory serves only as a temporary place along a migration route. We may infer the pattern of distant migrations by repeated recording of marked specimens during course of three years. At the end of April 1975 near the Southern slopes of Malaïsary mountains we marked 132 specimens and in 1976-1978 we recaptured 43 of them (32.20%), at distances 40-1220 m away. There is no difference between the length of the male and female movement but the distances covered increase with time. One year later this distance was 700 m, two years later it was 950 m, and after three years it reached 1220 m. Various factors are responsible for the migrations of the tortoises. They may be connected with the extention of the range of the species, with the peculiarities of behaviour during the breeding period, with search for food and places suitable for laying eggs and for wintering. Sometimes they are confined by the agricultural activity of man. The animals which remain alive during ploughing concentrate at the edges of the field and In untouched habitats. Tortoises will avoid places with constant trampling of cattle and intensive shepherding. The decrease of the number of tortoises observed in recent years may be explained by many factors. First of all it was influenced by the wide reclamation of virgin lands which has decreased their life space. Agricultural development with a high degree of mechanization is usually accompanied by death and mass trauma of the tortoises. Tortoises stay viable even after gross damage to the horned layers of the carapaces, such as losing many plates (usually marginal, nasal and tail) or claws. Females are able to carry and lay eggs even with greatly twisted carapace. Everywhere the areas studied by us are used for herding either all year round or during winter and spring. A great part of the juveniles tortoises with soft carapaces die under the hoofs of animals. Tortoises subject to highway mortality when passing tracks and paved roads. Thus, on the road from Kapchagal-Malaïsary and Kapchagaï-Arkharly along a 52 km route there was one crushed tortoise in every kilometre. During the frequent fires which appear at the time of burning the ephemeral plant communities, all tortoises caught by the fire above the ground die. Specimens with burnt parts of the body lose their mobility and become the prey of predators. The sustained and mass exploitation of tortoises in Kazakhstan and in other republics has as adverse influence on the numbers of this species. During the last five years large scale exploitation was permitted to meet demands of the world market for tortoises. Yet almost half of the trapped animals are sold within the country for keeping in captivity as a pet. Thus in 1978, of 160 000 tortoises only 77 000 (48%) were exported, the rest were sold via pet shops. In urban conditions tortoises die as a rule during the first year of their life in captivity because of inexpert maintainance and ignorence of the requirements of these animals. For rational utilization of Horsfield's tortoises we recommend the following: 1. It is necessary to continue and to extend the investigation on the sizes of the tortoise population, paying particular attention to the pattern of distribution, to the correlation of areas with different densities, to the influence of harvesting on the age and sex composition of the population and to the estimation of population size over large areas. 2. It is necessary to ban the sale of tortoise as a household pet and thereby decrease the number of tortoises captured by half; to limit the collection of immature specimens and males; not to allow the total removal trapping of the reptiles, harvesting should be done by small parties, leaving a part of the population untouched. 3. In order to enable the tortoises to breed to reproduce partly their population and to recover their weight, exploitation should not begin earlier than May. 4. It is necessary to stop the many-years exploitation of one and the same grasslands: collecting areas should be devided into plots, which should be used in rotation with intervals of several years in between harvesting; arable lands with agricultural crops should be cultivated during the first turn of rotation.