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.

have become devoid. As from 1975, in response to our initiative, exploitation has been banned in this territory, yet their numbers have not recovered so far, and it is only in some places that populations are apparently on the increase. A comparatively high density has been observed in the vicinity of Bozoi (7.1 specimens per hectare). Tn another areas of the Alma-Ata oblast 0.5 to 3.7 individuals per hectare. In the conditions of a sand desert (along Kolshengel-Topar road, near Aidarly, Akkol, Bacanas, Bakbakhty settlements) their density is 2 to 3 animals per hectare. Similar densities have been observed in the Taldy-Kurgan oblast at the southern extreme of the sand desert Sary-Ishik-Otrau, west of Ainabulak. In the Dzhambul oblast the main transect was laid along the boundaries of the Muyun-Kum desert. The largest density was recorded in the neighbourhood of Taldyosek (11.3 individuals per hectare). In old saksauls sometimes 16-26 specimens per hectare were recorded, on takyrs and on rocky and greasy soils only 2.4-3,4. The high density is characteristic not only for plain districts but for mountain plots as well at 1200-1300 m altitude. So, cm the northern slopes of the Kirgiz mountains in highly rugged places near Akyrtobe settlement, about 17.5 tortoises live on one hectare. On flat slopes they are rare (5.5 specimens per hectare). In other places (at Novotroichkoe, Ulanbel, Bostangyk, Sarybarak settlements) the density is 0.6-4.7 tortoises per hectare. In the Chlmkent region the surveys were carried out in central districts. Near Shaulder settlement and southward to Kolgykol lake the density of tortoises was found to be 0.5-3 specimens per hectare. They were numerous west of (26 per hectare) and south of Arys town (6,7-11.5 per hectare). Near Krasnyï Most it was 5.1 in some places being 26. It more northernly districts the density falls to 0.5-1.5 individuals per hectare because of soil greasiness and poor plant communities. Thus, in spite of the wide distribution of Horsfleld's tortoise relatively high populations have been found only at some localities. In the Alma-Ata oblast they include Kerbulak and Tsingildinskij massifs and the neighbourhood of Bozoi, in Dzhambul oblast they are the territories at Taldy-Ozek, Akyrtobe, in Chimkent oblast it is Arysskii massif and the neighbourhood of Krasnyï Most settlement. Nowadays similar densities are rare In Turkmenia, Tadzhikistan, Uzbekistan (ATAEV 1979, BOGDANOV 1978, KOROTKOV 1967, MAKEEV 1974, 1979, SAID-ALIEV 1979). It should be mentioned that the areas surveyed were chosen so as to reflect the heterogeneous distribution of the tortoises. On one and the same routes passing through equal ecological conditions, there are places with high and low densities or completely empty grasslands, where along several kilometres it has been possible to meet only single specimens. We have observed that Horsfield' s tortoise grows slowly and unequally and mainly till reaching sexual maturity. So, at Chyngildy settlement the growth of females during 12 years was about 100 mm, then till 16-17 years it was only 25 mm. Males grow slower and have smaller sizes and weight. The differences between the two sexes at the age of 16 years Is illustrated by data from Chyngildy, Akkuduk and at the southern slopes of Malaïsary mountains; 25 mm (412 g), 33 mm (450 g), 29 mm (357 g). Marked specimens increased in size during the active period by 1.3 to 7.5 mm (on an average 4.2 mm). The maximum size of males is 164 mm (1100 g), that of females is 194 mm (1750 g). Horsfleld's tortoise is characterized by great seasonal variation in body weight. Weighed marked specimens have shown that after wintering (from middle April to May) males increased in weight 19% on the average, females only 9.8%. In spring tortoises feed intensively, their gastro-intestinal tract is usually filled with vegetable food, sometimes consisting up to 15% of the mass. A considerable reserve of fat Is deposited in the liver. For instance, In 1975 the relative weight of this organ during the active period of females was increased from 2.5 to 9.1%. It increases especially after the deposition of eggs, therefore those females which are delayed in deposition go wintering less nourished. Males and juveniles ?how a more even rate of storing energetic reserves. Tortoises are active for 2.5-3 months from the end of March to the middle of June. The rest of the year they spend in shelters, though some of them become active again in summer and autumn. The peculiar seasonal activity of individuals of different sex and age lies in that there may be a lag in the time of becoming active In spring and aestivation in summer. Males are the first to appear and to the middle of April they are in majority. Then females and juveniles appear. Males aestivate before females which are active to the middle or end of June.