Authors: Miguel Tejedo, Ricardo Reques, And Marisa Esteban

Authors: J. L. D. Kauffmann, L. D. Brady And R. K. B. Jenkins

Authors: Indraneil Das

Authors: Julio A. Lemos-espinal, Geoffrey R. Smith, And Royce E. Ballinger

Authors: Massimo Capula , Luca Luiselli , Lorenzo Rugiero, Fatima Evangelisti , Claudio Anibaldi And Ve Ronica Trujillo Jesus

Abstract: The food habits of Coluber hippocrepis nigrescens, a colubrid snake endemic to the island of Pantelleria in the southern Mediterranean Sea, were studied by means of both stomach contents and faecal analyses. Snakes preyed only on vertebrates, and most of the prey eaten were rodents (especially Rattus norvegicus). Ingested biomass per snake averaged 55.63±48.94 g (range: 8 - 131 g), i.e. about 28.5 % of the average snake mass (195.18 ±65.61 g; range: 39-277 g). Log prey mass and log predator mass were positively correlated. The prey mass to predator mass ratio was not significantly correlated with log predator mass. 3 6.36% of the prey found in C. hippocrepis stomachs was eaten by snakes when it was already carrion, as demonstrated by the presence of abundant flesh-fly larvae in rats regurgitated by snakes. This is a very unusual foraging mode for snakes, which are known as active predators feeding on live organisms. We hypothesize that this unusual foraging mode is an adaptive strategy depending on (I) low level of food availability and (2) high abundance of dead prey, on this arid Mediterranean island.

Authors: Mark Wilkinson

Abstract: Previous phylogenetic analyses of the relationships among five Central American salamanders of the genus Dendrotriton are reviewed. The available data was reanalysed using parsimony under a variety of analytical treatments. The results are highly sensitive to (I) the coding method used to convert quantitative characters into discrete character states; (2) different scalings (weighting) of multistate characters; and (3) the omission or inclusion of potentially problematic characters. Explorations of length differences between most parsimonious trees and selected less parsimonious alternatives reveal that under each treatment, most parsimonious trees are only marginally more parsimonious than alternatives and that Bremer support for the clades occurring in MPTs is always low. Tree length distributions are not highly left-skewed as would be expected of phylogenetically informative data. These analyses suggest that there is little phylogenetic signal in the available data and that these data provide little basis for well supported phylogenetic inferences. Both parsimony and compatibility-based randomization tests confirm this interpretation. The null hypotheses that the data are not significantly different from phylogenetically uninformative randomly permuted data cannot be rejected for any of the analytical treatments. Given failure to reject the null hypothesis, phylogenetic hypotheses for Dendrotriton based on the available data are uncompelling. Additional data are needed. Results of the randomization tests are consistent with the view that there has been extensive homoplasy in bolitoglossine salamanders.

Authors: Laura E. Vega

Abstract: The lizard Liolaemus multimaculatus inhabits coastal sand dunes of the Buenos Aires Province of Argentina, and exhibits reproductive activity during the spring and early summer months. Females had vitellogenic follicles and oviductal eggs between September and December, and the size at maturity was 48.2 mm (snout-vent length). Five females with yolked follicles as well as eggs were collected in November, indicating that at least some females can produce more than one clutch per reproductive period. Mean clutch size was 4.2 eggs (range 3 to 7) and clutch size was positively correlated with female body size. In males, testicular diameter pe ked in August (late winter) and September (early summer) and declined in January (mid-summer). Testis size increased gradually from January onwards. Individual males were seen more frequently during the reproductive period than females. Hatchlings were first seen in February and March and the smallest measured 26. 7 mm (snout-vent length). Liolaemus multimaculatus males were larger than females in several morphological traits: snout-vent length, head length, distance between fore and hind limbs, tibio-fibulla, hand and foot lengths.

Authors: T . Kovacsánd J.Török

Abstract: Rarefaction analysis was applied to determine the minimum sample size required for any desired degree of accuracy of diet diversity of six anuran species in a particular habitat. This method is suggested for the design of sampling strategies in long-term amphibian studies. In the present study the minimum sample sizes were 28, 36, 32, 1 3 , 24 and 8 for Rana esculenta, R. arvalis, Hyla arborea, Bombina bombina, Pelobates fuscus and Bufo bufo, respectively. The greater the diet diversity of a species, the larger the minimum sample size required, and the smaller the simila ity between individuals within species.

Authors: A. S. Cooke

Abstract: A housing estate was built immediately adjacent to two water bodies utilized by crested newts (Triturus cristatus). Conservation management, particularly pond deepening and fish removal, was undertaken during and after development. This paper describes a monitoring study to determine the success of the operation. Counting adults at night in the breeding season indicated that numbers were at least maintained over a ten year period. Larval counts were made in each of the seven years after the houses were constructed, and more than half of the larvae wer e netted in one year, 1991. In the autumn of 1 990 both ponds were totally dry, and success in 1991 may have been associated with absence offish and low numbers of invertebrate predators. The overall conclusion was that it is possible to conserve crested newts satisfactorily in such a situation.