Authors:  Marko Andjelković, Veljko Blagojević, Ljiljana Tomović, & Ana Ivanović

Abstract: We examined the divergence in pileus shape and ontogenetic allometric changes in pileus shape in two closely related species of snakes - Natrix natrix and N. tessellata. These two species have similar ecology, but different microhabitat and diet preferences. We analysed the ontogenetic series from hatchlings to adults. Hatchlings of two species significantly diverged in pileus size and shape. At the adult stage, significant sexual dimorphism in pileus size and shape was found within both species. Adults of N. natrix and N. tessellata (females and males) diverged in pileus shape, but not in size. Allometric shape changes accounted for significant amount of variance in pileus shape among different age classes, and appear to be species- and sex-specific. Our results suggested that allometries of pileus shape are highly evolvable traits, which may result from natural selection for functional optimisation of head shape in Natricine species.

Keywords: geometric morphometrics, head scales, Natricinae, ontogenetic trajectories, sexual dimorphism

Authors: Oscar A. Stellatelli, Carolina Block, Laura E. Vega, Juan P. Isacch & Félix B. Cruz

Abstract: Home ranges of lizards are the result of both internal (body condition, reproductive status) and external factors, such as habitat features and resource availability. Habitat modification induced by introduced plants affects habitat use for lizards by changing food abundance, environmental temperatures or by homogenising the habitat structure. We compared the home range of the lizard Liolaemus wiegmannii in two situations: a partially forested habitat (20% of the total surface covered by Acacia longifolia) and a non-forested habitat. Twelve adult lizards were radio-tracked in the forested habitat and ten in the non-forested site. Home ranges were calculated using the minimum convex polygon method. The mean home range size was 37.80±17.95 m2 and was not different between both habitat types. Home ranges of males were 1.6 times larger than those of females. Abundance of food was highest in the forested habitat, without an apparent effect on home range size. Home range in L. wiegmannii showed a marked association with mixed patches of native grassland, bare sand substrates and scarce coverage of exotic trees. Our data suggest that movements in L. wiegmannii may be mainly related to structural features (and their associated thermal cues) of specific microhabitat types. Although low levels of forestation with A. longifolia have less effect on the home range size and movements of lizards, we cannot ignore previous results showing that occurrence, abundance and body condition of L. wiegmannii are negatively affected by extensive forestation of exotic plants both at local and landscape scales in pampasic dunes.

Key words: exotic plants, grasslands, home range, Liolaemus, radio-telemetry, sand lizard

Authors: Diego A. Barrasso, Leandro Alcalde, Boris L. Blotto & Néstor G. Basso

Abstract: This paper describes the external and buccal cavity morphology, chondrocranium, hyobranchial apparatus and cranial muscles of Alsodes neuquensis in comparison with the sibling species A. gargola. The tadpole of A. neuquensis presents a shorter and higher tail, and a relatively smaller oral disc than A. gargola. The external larval morphology of Alsodes may be characterised as follows: (i) tooth row formula 2(2)/3(1), (ii) single row of marginal papillae with a wide rostral gap, (iii) single row of submarginal papillae in the mental region, (iv) both supra- and infraangular submarginal papillae present. The buccal features do not show marked intrageneric differences. The anterior and/or posterior pair of infralabial papillae may be simple or forked. All known tadpoles present one prenarial papilla accompanied or not by few pustules, and the lateral ridges of floor can be three to penta-armed. The chondrocranial features shared by the species of the genus Alsodes are (i) tetrapartite cartilage suprarostralis, (ii) chondrified adrostral tissue mass, (iii) processus anterolateralis of the larval crista parotica well developed or larval processus oticus, and (iv) large processus pseudopterygoideus that may be either completely fused to the basi cranii (A. vanzolinii, A. verrucosus and some A. neuquensis) or fused only at the tip (A. barrioi, A. gargola and some A. neuquensis). Larval cranial muscles are for the first time described for the genus Alsodes. They do not show differences between both species studied herein.

Key words: buccal cavity morphology, cranial muscles, cranial skeleton, external morphology, larvae

Authors: Bryony A. Tolhurst, Vanessa Aguirre Peñafiel, Paola Mafla-Endara, Maureen J. Berg, Mika R. Peck & Simon T. Maddock

Abstract: The cloud-forests of the Western Ecuadorean Andes are highly diverse and under threat from anthropogenic habitat disturbance. Reptiles are sensitive to habitat change and are therefore useful indicators of ecosystem state. Overall diversity has been shown to be highest in old-growth (primary) forest, although older secondary forests can recover to near pre-disturbance levels. We systematically surveyed leaf-litter lizard diversity along a gradient of disturbance in a montane cloud-forest fragment whilst controlling for the potentially confounding effect of elevation. We deployed 21 pitfall trap-lines equally between primary forest, secondary forest of mid-age (18–30 years), and agroforestry, between three altitudinal bands for ten days each over a period of three years. We investigated diversity patterns using Chao 1 and 2 indices (estimated richness), effective species number (ESN), relative abundance of individual species, relative abundance of pooled species, and observed species richness. We also conducted an opportunistic inventory of reptile species. We recorded 7 species of leaf-litter lizards and 15 other species of squamate, the majority of which are rare, recently described and/or of restricted distribution. Elevation was strongly negatively correlated with diversity. Richness and most indices of diversity were higher in primary forest but abundance was similar in primary forest and agroforestry. ESN followed a negative linear response to disturbance but for all other measures agroforestry supported diversity that was either higher than or equal to secondary forest. We conclude that, particularly at high elevations, mid-aged secondary forest is depauperate of leaf-litter lizards but agroforestry potentially supports relatively large populations of generalist species.

Key words: Andes, cloud-forest, disturbance, Ecuador, lizard

Authors: Florina St?nescu, Federico Marangoni, Ivana Reinko & Dan Cog?lniceanu

Abstract: We explored age-related parameters and growth patterns in a population of Dermatonotus muelleri inhabiting the Arid Chaco, at the southern limit of the species’ distribution range using skeletochronology. In addition, we studied sexual size dimorphism and female reproductive investment. Males and females attained sexual maturity at a similar age (2 years) and both had a low reproductive lifespan (3 years). Females were significantly larger than males and had a higher reproductive investment compared to other anurans. The growth rate coefficient (k) was similar in males (1.14) and females (1.07), indicating that the sexual size dimorphism in this species is caused by differentiated growth before sexual maturity. Overall, we suggest that the short reproductive lifespan justifies the high reproductive investment in the studied population.

Key words: age, explosive breeder, growth, reproductive investment, sexual size dimorphism

Authors: Jan W. Arntzen, Tania M. King, Mathieu Denoël, Iñigo Martínez-Solano & Graham P. Wallis

Abstract: The last century has seen an unparalleled movement of species around the planet as a direct result of human activity, which has been a major contributor to the biodiversity crisis. Amphibians represent a particularly vulnerable group, exacerbated by the devastating effects of chytrid fungi. We report the malicious translocation and establishment of the alpine newt (Ichthyosaura alpestris) to its virtual antipode in North Island of New Zealand. We use network analysis of mitochondrial DNA haplotypes to identify the original source population as I. a. apuana from Tuscany, Italy. Additionally, a population in southern France, presumed to be introduced, is identified as I. a. alpestris from western Europe. However, the presence of two differentiated haplotypes suggests a mixed origin. This type of analysis is made possible by the recent availability of a phylogenetic analysis of the species throughout its natural range. We discuss the particulars of both introductions.

Key words: Alpine newt, France, Ichthyosaura alpestris, introductions, mtDNA, New Zealand

Authors: Krzysztof Dudek, Ryszard Koczura, Monika Dudek, Zofia Anna Sajkowska & Anna Ekner-Grzyb

Abstract: Salmonellosis is one of the most urgent public health problems across the world. Reptiles are a known reservoir of Salmonella spp. and in some regions they are also associated with human salmonellosis. This concerns especially popular pet reptiles, e.g., turtles or bearded dragons; however, there is also a need for studies regarding wild reptiles as a pathogen source. In this study, sand lizards (Lacerta agilis) were investigated as a potential reservoir of Salmonella spp. in Poznań, Poland, using cloacal swabs and faecal samples. Moreover, clonal analysis of the isolates was conducted using ERIC-PCR fingerprinting. Thirty eight lizards were investigated, nine of which (24%) proved positive for S. enterica subsp. houtenae. The prevalence level was lower than previously observed in exotic species (up to above 40%). Two clones were present in several lizards. Specimens with similar clones were captured at the same location and time, suggesting horizontal transfer of bacterial strains between lizards. Because the isolated subspecies of Salmonella is very rarely reported as a causative agent of human salmonellosis, sand lizards seem to pose little or no threat for public health.

Key words: clonal analysis, environmental microbiology, infectious disease, reptile-associated salmonellosis

Authors: Mariana Pueta, Félix B. Cruz & M. Gabriela Perotti

Abstract: Movement makes prey more vulnerable to predators. Antipredator responses usually have associated costs such as reduced feeding activity, and decisions made under predation risk may be affected by the feeding state of the prey. In this study, we evaluated whether food regime influences antipredator behavioural responses of Pleurodema thaul tadpoles (diet treatment) before adding food or water (incentive treatment) while the tadpoles were exposed to alarm cues. Under predation risk, normally fed tadpoles showed decreased overall activity, whereas poorly fed tadpoles spent more time feeding after food was provided. Tadpoles in all treatments decreased their swimming activity but not their feeding activity. Our study showed that swimming behaviour was more sensitive to predation risk than feeding behaviour. We suggest that the motivational state of tadpoles under different environmental conditions should be considered when behavioural patterns are analysed to understand short-term trade-offs between foraging requirements and predator avoidance. 

Key words: behaviour, diet, food availability, foraging, predation risk, tadpoles