2016-12-23T18:52:10

I n a population of adders (Vipers b e w ) in Southwest Sweden, melanistic males were heavier than normal coloured males of the same length. Victory in male-male sexual combats was positively related to size. Higher risk ofpredation in the black morph was inferred from experiments showinga high predator attack rate on models of the black morph. Even the bright colour in newly moulted basking males of the normal morph gives cryptic protection. In females, melanism probably also attects body size and risk of predation by visually searching predators. The thennoregulatory influence of black colour, the reproductive success and the maintenance of two colour morphs in the population are discussed.

The effects of pH and aluminium on embryonic and early larval stages of Swedish brown frogs Rana arvalis, R. temporaria and R. dalmatina were tested in laboratory bioassays. In all three species egg mortality and time needed for embryonic development to hatching increased when pH declined, but no significant effects were found on embryonic development when aluminium level was elevated. In R. arvalis and R. temporaria larval mortality was affected by both pH and aluminium. In both species the frequency of occurrence of larval deformities increased in acid water, and there was a synergistic effect of pH and aluminium. In R. arvalis swimming behaviour was disturbed by high levels of aluminium at pH 5. In all three species the frequency of stressed larvae increased when pH was depressed and aluminium concentration elevated, and there was a synergistic effect when both were combined. The three species differed significantly in egg mortality, time needed for embryonic development, larval mortality, larval deformities and larval stress al low pH and high aluminium levels. R. arvalis showed the highest acid tolerance and R. dalmatina was the most sensitive to low pH.

The Anatolian "Diagonal" divides Turkish Anatolia into two major zoo- and phytogeographical regions. Along this "Diagonal" a series of closely related species of vipers are distributed: Vipera bornmuelleri, Vipera bulgardaghica, and Vipera wagneri. To this series a new species, Vipera albazona sp. n. is added. The importance of this "Diagonal" as a mechanism for dispersal and speciation is also discussed.

Courtship, mating and agonistic behaviour in free living adders, Vipera berus, are described. Temporal associations between behaviour patterns within and between individuals are analyzed to test motivation and signal functions. Differences in combat behaviour in males meeting for the first time and later are examined. The function of combats and territorial defence is discussed.