The Herpetological Journal

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Authors: Loader, Simon P.; Wilkinson, Mark; Cotton, James A.; Measey, G. John; Menegon, Michele; Howell, Kim M.; Müller, Hendrik & Gower, David J.

Abstract: Phylogenetic relationships of the East African caeciliid Boulengerula were reconstructed using 12S, 16S and cytb mitochondrial gene sequences for 32 samples from Kenya and Tanzania. The generally well-supported and resolved phylogeny displayed the following relationships among the five nominate species sampled: (B. boulengeri ((B. taitanus, B. niedeni), (B. changamwensis, B. uluguruensis))). This resolution supports a formerly proposed bipartition of the genus, and differs significantly from previous, morphological phylogenies. Our analyses identified genetic differences between several mtDNA clades that potentially represent undescribed species. If substantiated, the necessary taxonomic revision will have implications for conservation assessments that depend to an important extent upon sizes of distributions. Overall, there is a positive correlation between genetic and geographic distance among and within the main clades. The two lowland, coastal individuals sampled are nested within primarily montane clades. Dating analyses suggest some temporally congruent divergences in Boulengerula, but other divergences happened at different times and over a long period, perhaps extending back to the Oligocene/Eocene. Our results for Boulengerula suggest a role for relative long-term environmental stability in the origins of the Eastern Arc Mountains biodiversity hotspot.

Keywords: KENYA, MTDNA, TANZANIA, EASTERN ARC MOUNTAINS, CAECILIANS

pp. 17-26
Authors: Köhler, Angela; Sadowska, Julita; Olszewska, Justyna; Trzeciak, Paulina; Berger-Tal, Oded & Tracy, Christopher R.

Abstract: Ambient temperature largely determines the body temperature of amphibians, and thus their hydration state and physiological performance. Microhabitat conditions chosen by terrestrial amphibians may represent a trade-off between high ambient temperatures, which maximize performance but cause high rates of water loss, and low temperatures, which, in turn, slow desiccation, but potentially hinder performance. We determined the operative temperature of common frogs (Rana temporaria) by placing 3% agar models in different microhabitats and measuring their temperature and water loss. Temperature measurements derived from the models accurately matched the body temperature of live frogs placed in the same microhabitat. Operative temperatures were lower than ambient temperatures on a warm day, probably because of evaporative water loss, but they were similar to or even slightly higher than ambient temperatures on a cool day, possibly because of warmth from the substrate. Frogs in the field selected moist and cool habitats, and their body temperatures ranged from 15 to 21 °C. In a temperature gradient in the laboratory, captive frogs chose significantly higher temperatures (19.4±1.7 °C) when the gradient floor was covered entirely with wet sand than when sand was wet in the cool end, but dry in the warm end (17.6±2.5 °C). The relevance of the preferred temperature was assessed through jumping performance experiments, using frogs with different body temperatures. Jump length was lower at low body temperature (6 °C) than at higher body temperatures, and peaked at 15 °C. Our results suggest that the frogs select favourable microhabitats of intermediate temperature, which could result in reduced water loss and peak physiological and behavioural performance.

Keywords: BODY TEMPERATURE, MICROHABITAT, SKIN TEMPERATURE, THERMAL GRADIENT, JUMPING PERFORMANCE, AGAR MODELS

pp. 27-34
Authors: Tapley, Benjamin; Griffiths, Richard A. & Bride, Ian

Abstract: This study compared the trade in reptiles and amphibians in the United Kingdom between 1992–3 and 2004–5. In particular, the impacts of captive breeding and colour and pattern morphs on price structures were examined. The number of amphibian and reptile species in the trade more than doubled over this period, and less than a third of the species traded were common to both trading periods. More traded species were listed by CITES in 1992–3 than in 2004–5. Taking into account inflation, the study showed that the price of all groups of reptiles and amphibians recorded increased over the ten-year period, and that some snake species had done so dramatically when colour and pattern morphs were considered. The price change of chelonians was probably the result of responses to changes in various trade regulations. Price increases for amphibians seemed to represent their increased popularity, coupled with the overhead costs of captive breeding on a commercial scale being transferred to the hobbyist. The increased popularity of captive-bred colour and pattern morphs could alleviate pressure on wild stocks. On the other hand, as such animals are predominantly being produced outside their countries of origin, no benefits accrue to local people and trade could undermine sustainable use programmes for wild animals.

Keywords: SUSTAINABILITY, ECONOMICS, WILDLIFE TRADE, CITES

pp. 35-42
Authors: Pincheira-Donoso, D.; Fox, S.F.; Scolaro, J.A.; Ibargüengoytía, N.; Acosta, J.C.; Corbalán, V.; Medina, M.; Boretto, J.; Villavicencio, H.J. & Hodgson, D.J.

Abstract: Body size influences patterns of variation in several of the most important traits directly linked to fitness. Therefore, the establishment of informative proxies for body size is a critical aim in ecological and evolutionary research. Among lizards, snout–vent length (SVL) is the most widely used proxy for body size. However, since SVL is a linear measure of size, it fails to capture body shape variation. This limitation is largely resolved by the use of body mass, a multidimensional measure of size that is unfortunately rarely considered and reported. To circumvent this restriction, a classic allometric equation (Pough's equation) was proposed to convert SVL into mass. Nevertheless, the predictive power of this equation has been assumed rather than empirically tested for almost three decades. In a recent study on lizard size allometries, additional equations were derived for different groups separately, suggesting that more clade-specific equations are likely to perform better. Here, we investigate the precision of these allometric equations using two sister lizard genera (Liolaemus and Phymaturus), members of the Liolaemidae radiation, for which SVL and mass have been measured. We found that our equations differ significantly from the two more general equations primarily in intercepts, while the more clade-specific equation derived for Tropiduridae lizards is fully compatible with our equation for Liolaemus and showed only a borderline statistical difference with Phymaturus. Therefore, although more clade-specific equations may reliably predict body mass, more general equations should be used with caution in lizard ecological and evolutionary research. Previous allometric equations proposed to predict mass from length in other ectotherms should be quantitatively assessed before being employed.

Keywords: LIZARDS, PHYMATURUS, LIOLAEMUS, ALLOMETRY, BODY MASS

pp. 43-50
Authors: Bastos, Rogério P.; Alcantara, Mariana B.; Morais, Alessandro R.; Lingnau, Rodrigo & Signorelli, Luciana

Abstract: We describe the vocal repertoire of Scinax centralis (Anura, Hylidae), examine the influence of individual characteristics on acoustic parameters, and explore the role of sound level in aggressive interactions. Observations were carried out between January 1997 and June 2001 in a rivulet at Floresta Nacional (Flona), municipality of Silvânia, state of Goiás, Brazil. Male S. centralis emitted four distinct types of vocalizations: an advertisement call, two types of aggressive call and a displacement call. Early in the nightly vocalizing activity, males emitted more aggressive calls and few advertisement calls. Males called at faster rates when inter-male distances were shorter. The mean intensities of the three calls (advertisement call, long and short aggressive calls) were positively correlated with the number of individuals present in the chorus, as well as snout–vent length (SVL) and mass of the calling male. The mean dominant frequency was negatively correlated with SVL and mass. Males increased the number of advertisement or aggressive calls during playback compared to pre-playback periods. Mean call intensity significantly increased with playback SPL. Like other species, Scinax centralis presents a complex vocal repertoire, with males emitting four types of vocalizations depending on social interactions.

Keywords: ANURA, AGGRESSIVE INTERACTIONS, HYLIDAE, VOCALIZATIONS, SOUND LEVEL

pp. 51-57
Authors: de Fraga, Rafael; Lima, Albertina Pimentel & Magnusson, William Ernest

Abstract: Large-scale biogeographical determinants of snake assemblages may underestimate the effects of local factors that operate within restricted areas. We determined the influence of ecological gradients on the richness and species composition of snakes in the Reserva Ducke, Manaus, Amazonas, Brazil. Multivariate analyses revealed aspects of habitat selection by snakes which would be impossible to detect with large-scale approaches. There was no evidence for a relationship between the number of species recorded per plot and any of the variables measured. However, the species composition, based on a matrix of Chao dissimilarities between plots, differed significantly between riparian and non-riparian areas. The results have important implications for management and conservation, because Brazilian environmental legislation only provides protection up to 30 m away from streams like those of Reserva Ducke, while snakes use larger riparian areas. If only the areas contemplated by law are protected, the majority of species associated with riparian areas are at risk.

Keywords: RIPARIAN ZONES, TROPICAL RAINFOREST, ECOLOGICAL GRADIENTS, COMMUNITY STRUCTURE

pp. 59-64
Authors: Bombi, Pierluigi; Akani, Godfrey C.; Ebere, Nwabueze & Luiselli, Luca

Abstract: During the last 15 years, intensive field research has been conducted on the ecology and population abundance of the Gaboon viper (Bitis gabonica) and the nose-horned viper (Bitis nasicornis) in southern Nigeria. During these studies, we determined the occurrence of several high-abundance and low-abundance populations for these two species. In the present study, we analysed the potential effects of climate change by modelling the current dataset on viper abundance (both high and low) using generalized additive models. We used climatic surfaces of current conditions as spatially explicit predictors, and projected viper abundance into a future climatic scenario. The future climatic conditions seemed appropriate for a wide extension of the climatic niche for high-abundance Gaboon viper populations across our study area. On the contrary, the future climatic niche for high-abundance nose-horned viper populations is predicted to become narrower than at present. In future scenarios, the two species are predicted to have a larger overlap in their climatic niche, which is likely to increase interspecific competition.

Keywords: VIPERIDAE, WEST AFRICA, CLIMATE CHANGE, GAM, MODELLING

pp. 65-72
Authors: Ljubisavljević, Katarina and Polović, Lidija and Urošević, Aleksandar and Ivanović, Ana

Abstract: We applied a geometric morphometrics approach to examine sexual size and shape dimorphisms (SSD and SShD) in dorsal and ventral skull portions and cephalic scales (pileus) in the lacertid lizard Algyroides nigropunctatus. We found significant sexual dimorphism in all three structures that are mostly attributable to allometry. Males and females share allometric trajectories for the pileus and dorsal portion of the skull, i.e. the significant differences in shape between sexes are due to differences in size. Regardless of sex, allometric shape differences between small and large individuals show negative allometry in the anterior parts and more pronounced positive allometry of the parietal region in the dorsal skull and pileus. We observed a marginally significant divergence in sex-specific allometric trajectories of the ventral skull. The similar patterns of covariation between the ventral skull and the dorsal skull portion and pileus indicate close relationships between the skull bones and cephalic scales. The stronger covariation between the ventral and dorsal skull portion in males compared to females raises the question whether sexual dimorphism in the structure of morphological variation of the lizard skull exists.

Keywords: CRANIUM, PILEUS, GEOMETRIC MORPHOMETRICS, ALLOMETRY, SEXUAL SIZE DIMORPHISM, SEXUAL SHAPE DIMORPHISM

pp. 73-81
Authors: Luiselli, Luca; Rugiero, Lorenzo & Capula, Massimo

Abstract: Snakes are rather difficult subjects for demographic studies. When snakes are not abundant in the field, herpetologists have learnt that a good method for population studies is to rely on mass captures at den sites. In several snake species females also exhibit oviposition at communal nest sites, which are utilized year after year. These oviposition sites may then serve to record individuals for snake population studies. Here, we compared population size estimates generated from a 17-year study of gravid females at a communal nesting site (CNF) with population size estimates from the same snake population across an 8-year traditional capture–mark–recapture (CMR) study. Although in our case only open population methods are appropriate for calculating yearly population sizes, we also used closed population methods in order to highlight an eventual effect of the models used. As a study species, we used the European whip snake (Hierophis viridiflavus) at a site in Mediterranean central Italy. Overall, population size estimates were significantly different between the two methods, with estimates from the CNF samples always higher than those obtained with traditional CMR. This difference was particularly strong with closed population methods, but still evident with open population models when the whole study period was considered. However, there were no statistical differences between population sizes estimated with CNF and CMR when only a subset of years (2002–2009) was used. No statistical relationship between population size estimates with CMR against CNF by year was uncovered, showing that CNF samples did not capture inter-annual variations in population sizes. We conclude that it might not be sound to use population size estimates from CNF samples instead of more traditional CMR studies, although yearly population size variations may at least in part be responsible for the differences between CNF and CMR estimates.

Keywords: ITALY, FIELD TECHNIQUES, COMPARATIVE ANALYSES, SERPENTES, STATISTICS, DEMOGRAPHY

pp. 83-86
Authors: Ursprung, Eva; Ringler, Max; Jehle, Robert & Hödl, Walter

Abstract: Toe-clipping is a standard method for marking and tissue sampling in amphibians, and in most adult anurans such marks are permanent. Here we document the consistent regeneration of toes in the aromobatid frog Allobates femoralis during a three-year population study. The emergence of new toe discs was observed after about two months. After one year the regrown toes had recovered to 65.6%/63.8% (males/females) of the size of unclipped toes and after two years they had attained 74.0%/69.0%. Whereas toe discs before amputation were white dorsally, all but one regenerated toe discs were dark. We did not detect any malformations or infections of the digits. Recapture rates of toe-clipped individuals were indiscernible from those of a nearby population where no toe clips were taken. We discuss a possible link between toe regeneration ability and life-history attributes.

Keywords: TOE CLIPPING, DENDROBATOID, AROMOBATIDAE, AMPHIBIANS

pp. 87-90
Authors: Sztatecsny, Marc and Glaser, Florian

Abstract: Chytridiomycosis is a fungal disease that has been made responsible for amphibian declines around the globe. We found the causative agent of the disease, Batrachochytrium dendrobatidis, at six amphibian breeding sites in the eastern lowlands of Austria and four in the western parts of the country (30% of all sampled sites), including the highest record for the European Alps to date at 1630 m a.s.l. Nine amphibian species were infected, and metamorphosing Bombina bombina had the highest prevalence (40%). No individual showed obvious signs of disease, but our data are insufficient to draw any conclusions on disease-associated effects.

Keywords: ALPINE AMPHIBIANS, CHYTRIDIOMYCOSIS, INFECTIOUS DISEASE

pp. 91-94
Authors: Campos, Zilca & Magnusson, William E.

Abstract: We studied the emergence and basking behaviour of Pantanal caimans (Caiman crocodilus yacare) in relation to temperature. In the cold season, caimans were exposed to the sun, and air temperatures higher than water temperatures suggest that emergence behaviour may be due to thermoregulation. In the dry season, most (66%) emergent caimans were found in the shade between 1000 and 1500, and body temperatures rarely exceeded water temperatures. Caimans also emerged at night, although body temperatures were highly correlated (r=0.974, P<0.001) with water temperatures, suggesting that emergence is related to factors other than thermoregulation.

Keywords: SOCIAL BEHAVIOUR, CONSERVATION, BASKING, PANTANAL CAIMAN