Authors: Pietro Lo Cascio, Claudia Cortl2 And Luca Luiselli

Authors: Itamar A. Martins

Authors: Trevor J. C. Beebee A D Graham Rowe

Abstract: We investigated sand lizard (Lacerta agilis) populations in Britain by genetic analysis across eight polymorphic microsatellite loci. Genetic diversity as determined by mean expected heterozygosity was high in all three distinct regions where the species occurs (Dorset, Surrey and Merseyside), though allelic diversity was lower on Merseyside than in Surrey or Dorset. There was significant genetic differentiation between populations in all three of these widely separated zones, as judged both by Fst and Rst estimators. A genetic test for population bottlenecks confirmed that in at least two of the areas currently inhabited, Surrey and Merseyside, L. agilis has undergone substantial recent dec lines. The significance of these findings for sand lizard conservation is discussed.

Keywords: sand lizards, Lacerta, conservation, genetics, microsatellites

Authors: Kyle Summers And Rebecca Symula

Abstract: Two experiments were conducted to investigate the influence of kinship on aggression and cannibalism in the Amazonian poison frog, Dendrobates ventrimaculatus, in eastern Ecuador. Firstly, we placed pairs of kin and pairs of non-kin tadpoles in plastic cups, allowed them to interact over a food item and videotaped their behaviour. The videotapes were analysed for aggressive and associative behaviour. Secondly, we placed pairs of tadpoles in manipulated natural pools in the field, and left them together for one month. The results of the videotaped behavioural experiments did not indicate strongly preferential treatment of kin, although biting was rare in the kin treatments but common in some non-kin treatments. The field experiments indicated that both kin and non-kin tadpoles are likely to be cannibalized if they coexist with larger tadpoles in Heliconia pools for a substantial period of time. Ultimately, the study was inconclusive with respect W the occurrence of kin discrimination. However, the study provides important information relevant to the study of kin discrimination by dendrobatid tadpoles in the field.

Keywords: cannibalism, kin recognition, Dendrobates, behaviour

Authors: Konstantinos Sotiropoulos , LjIljana Tomovic, Georg Dzuki And Milos L. Kalezic

Abstract: A comprehensive survey of the Balkan alpine newt was undertaken to describe morphological differentiation . between populations, and to test the validity of previously described subspecies. Thirty population samples derived from the major part of the Balkans, excluding Bulgaria and Albania, were studied for patterns of both morphometric and qualitative trait variability. On the basis of morphology, separate taxonomic status cannot be allocated to any of the currently recognized Balkan subspecies, with the exception of the southernmost ( T. a. veluchiensis). Paedogenesis affected morphological variability significantly. Variability among paedotypic populations was found to be lower than intrapopulation variability of metamorphosed individuals.

Keywords: Triturus alpestris, morphological differentiation, taxonomy, paedogenesis, Balkan Peninsula

Authors: Benedikt R. Schmidt And Adolfo Amézquita

Abstract: Many species show behavioural responses to predators that reduce predation mortality but are assumed to be costly. We tested whether an induced behavioural response is predator-specific and whether the strength is related to the risk of being killed by a predator. We used tadpoles of the neotropical frog Phyllomedusa tarsius as prey, and larvae of an aeshnid dragonfly and belostomatid bugs as predators. Belostomatids killed twice as many tadpoles within 24 hours as aeshnids did. Tadpoles reduced activity in the presence of aeshnids by 30% but did not respond at all to the more dangerous belostomatids. Tadpoles did not show spatial avoidance of predators. We favour the explanation that tadpoles of P. tarsius did not respond to belostomatids because belostomatids are encountered too rarely for evolution to favour an induced response to belostomatids.

Keywords: amphibian, distribution, induced response, Phyllomedusa tarsius, predation risk, tadpole