Licht-im-Terrarium: Literaturdatenbank

During eight years of a continuing long-term study of Vipera berus in a chalk downland nature reserve, records were made of encounters with all life stages at artificial refuges and in the open. The refuges were paired sheets of galvanised corrugated-iron ('tins') and roofing felt, deployed at the rate of 2.7 to 4.2 pairs/ha. Distinctive seasonal patterns of encounters are reported for each life stage and provide insights into viper behaviour. For adults, encounters in the open and at refuges both contribute significantly to records while for immature stages records depended largely on their use of refuges as they were rarely encountered in the open. All life stages were encountered at tins more frequently than felts. Gross encounter rates have been refined by reference to observations on 483 individuals recognised by their head-scale patterns. The numbers of different individual adult males and adult females observed in the open were broadly similar, as were the numbers under tins, but the frequency with which these individuals were resighted was greater in the open for males and greater under tins for females. At least in the case of gravid females, refuge use may be a substitute for mosaic basking. Under the conditions of this study, roughly 70% of individual adult vipers used refuges at least once, usually much more frequently, whilst for immatures the proportion remains uncertain. These observations could be used to improve the planning and interpretation of long-term monitoring studies.