L. Forró szerk.: Miscellanea Zoologica Hungarica 8. 1993 (Budapest, 1993)

Janisch, M.: A mutant form of the meadow viper (Vipera ursinii rakosiensis Méhely) from Hungary with a peculiar colour pattern

appearance, the disordered distribution of the spots resembles to a speckled pattern. Snout region, throat and the first ventral scales are light grey to whitish. Ventral side of the body is glittering, dark shale grey, with white hind margins similar to the scales on the side. From the alternating spots on the side only the lower series is well-developed, the upper one is usually missing, or remains only as tiny black points. In addition to the detailed description some black-and-white photographs are provided for closer observation (Figs 1-3). Terrarium experiences Life history of the gravid mutant female - compared to another gravid female with normal colouration - during their 95 days in terrarium is summarized in Table 1. The different events were regularly recorded on colour slide photographs. The animals were kept at the Department of Parasitology and General Zoology, University of Veterinary Science, in a glass terrarium of the size 80 x 50 cm (60 cm height) with a soil heater (temperature 24-27 °C). Five clumps of grass, two rock pieces, a small log and the drinking pot were the "furniture". During the 95 days the animals were put in the park of the University 12 times for one hour sunbathing. They sloughed three times, two of them were without any complication. Before sloughing, the specimens received a spray of warm water (28 °C). They have eaten altogether 8 mice, 2 small rats and 6 sand lizards (Lacerta agilis). On the 12th of July, 1987, the mutant female has given birth to 19 youngs (Fig. 4). Thirteen of them were similar in their colour pattern to the mother, so the mutant character appeared in a ratio of 13:6! The female with normal colouration had 12 normal youngs on 14th July. Conclusions On the 6th of August both adults and the 31 juveniles were taken back to their original biotope. In the action, Gábor Nechay, Ministry of Environment and Tamás Pécsy, Society for Nature Conservation and Ornithology, have also participated. The juveniles were released on the meadow in a distance of 50-80 m from each other. The vegetation was high, and provided a good shade for the vipers against the Montagu's harrier (Circus pygargus) breeding next to the meadow. As an explanation of this unique genetical change resulting in a peculiar colour pattern of the Vipera ursinii rakosiensis, perhaps the followings can be mentioned. During the last centuries the formerly continuous ancient meadows were fragmented by the human settlements and activities. The isolated populations of these small island biotopes decreased in number to such an extent, that their inbreeding became intensive, and the increasing gene mutations could produce, among others, interesting colouration changes and pattern differences, like in the case of the female described above. A similar case is mentioned by Nilson & Andren (1986, p. 28, Fig. 6.B) for Vipera raddei.