Authors: Rupert Stocks

Authors: M. R. Warburg

Abstract: The fire salamander, Salamandra salamandra, population on Mt. Carmel was studied for 15 years. This is a particularly interesting population as it inhabits the southern-most habitat in which this species is found in Israel, and thus the south-eastern fringe area of its entire palaearctic distribution.
The ovoviviparous female breeds during both November and December. The November cohort is likely to die of desiccation as the ponds dry out due to interrupted rains. Only every third year (on average) is November wet enough to enable the ponds to contain enough water, to give the larvae a chance to survive to metamorphosis. Some of these larvae will have an advantage, due to their cannibalistic traits enabling them to prey on the later larval cohorts of December. These cannibalistic larvae develop rapidly and metamorphose at a greater size than the average larvae.
The survival of this salamander population depends on a balance between two conflicting strategies: early breeding and late breeding. The first is advantageous during years with early winter rains when the larvae can survive long enough to be able to prey upon the later larval cohorts. On the other hand, late breeding is advantageous in dry years when larvae in the early cohorts die of desiccation.

Authors: Jesus Mellado And Jose A. Mateo

Authors: Floyd E. Hayes, William K. Hayes, Kent R. Beaman, And Lester E. Harris, Jr

Abstract: Sleep-like behaviour of Galapagos tortoises (Geochelone elephantopus) was studied at Volcan Alcedo, Isabela Island, Galapagos Islands, Ecuador. At midday, most tortoises found asleep were in the open with head and limbs extended; during cooler evening hours, sleeping tortoises usually occupied forms with head and limbs withdrawn. Variability in sleep-like postures during different periods of inactivity probably reflects alternative thermoregulatory strategies. Forms occupied by inactive tortoises (n = 53) comprised vegetation (5 1%), soil (30%) and other tortoises (19%). The absence of native predators on Galapagos implies a thermoregulatory rather than antipredator function for form use.

Authors: Maragou Panagiota And Efstratios D. V Alakos

Abstract: Data on the thermal ecology of Testudo marginata and T hermanni are presented. The two species are eurythermic and thermoconformers. There are no differences in the thermal relations between the species.

Authors: Umberto Agrjmi And Luca Luiselli

Abstract: During a three-year period of research on the viper Vipera ursinii ursinii, observations on diet composition and feeding strategies were obtained. The major food items in terms of percentage were orthopterans, followed by rodents, lizards, birds, spiders and beetles. A considerable seasonal change in the diet composition was noted: invertebrates predominated in the diet only between July and September, as compared to the spring diet which was made up of vertebrates.

Authors: M. Alcobendas, J. Castanet, E. Martelly And C. Milet

Abstract: The measurement of phosphate and calcium levels in the plasma of Vipera aspis during two consecutive year cycles shows significant seasonal variations. For males and non-breeding females, phosphate levels are higher during the active period of the year than during hibernation. Conversely, calcium levels appear generally more elevated for the hibernating period than for the active period. Breeding females present an important increase of phosphate and calcium levels with a peak near ovulation. Clearly, this phenomenon is related to vitellogenesis. The relationship between plasma phosphate and calcium levels and bone tissue mineralization is discussed, the latter being the only reservoir of these mineral salts available to the snake.