The Herpetological Journal

pp. 69-77
Authors: Barros, Verônica Alberto; Rojas, Claudio Augusto & Almeida-Santos, Selma Maria

Abstract: Two populations of the Neotropical lancehead Bothrops leucurus were studied in two locations in Brazil (Espírito Santo, ES, and Bahia, BA) with different rainfall seasonality patterns. The timing of reproduction was very similar in both populations, with the mating season occurring in autumn (when spermatozoa were found in uteri) and births occurring in summer. In males, spermatogenesis peaked in autumn, with evidence for increased secretory activity in the epithelium of the ductus deferens during the mating season in both populations. Our results indicate that phylogenetic inertia plays a major role in determining the timing of reproductive events in B. leucurus. However, snout-vent length (SVL) and clutch size were larger in individuals from BA than ES, which may be a result of differences in rainfall seasonality or other proximate factors (e.g., differential prey availability).

Keywords: SPERMATOGENESIS, REPRODUCTIVE CYCLES, ENVIRONMENTAL CONDITIONS, PHYLOGENETIC INERTIA, LONG-TERM SPERM STORAGE, CLUTCH SIZE

pp. 79-85
Authors: Alencar, Laura Rodrigues Vieira & Nascimento, Luciana Barreto

Abstract: Documenting intraspecific variation is essential to understanding the ecology and evolution of natural populations. Here we provide information on sexual maturity, sexual size dimorphism, fecundity and diet of Erythrolamprus poecilogyrus from the region of the Aimorés Hydroelectric Power Plant, southeastern Brazil, based on specimens deposited in the Herpetological Collection of the Museu de Ciências Naturais da Pontifícia Universidade de Católica de Minas Gerais. We also compare our results with those from previously published studies. We measured snout-vent length and tail length, and counted ventral and sub-caudal scales of each specimen. We also recorded reproductive aspects and diet identified to the lowest possible taxonomic level. Erythrolamprus poecilogyrus differed in overall body and clutch size between geographic regions, following a pattern inverse to Bergmann's rule. In general, females attained larger body size than males, but do not have a higher number of vertebrae. We did not find intersexual differences in tail length, which may be related to a low degree of intersexual competition among males. Diet composition was very similar throughout the species' range, and characterises E. poecilogyrus as an anuran specialist. Females maintained their feeding activity while gravid, suggesting that E. poecilogyrus is an income breeder, which is an adaptive strategy when foraging success is predictable during reproductive periods.

Keywords: LIOPHIS, INCOME BREEDING, XENODONTINI, REPRODUCTIVE BIOLOGY, DIET

pp. 87-96
Authors: Bellini, Gisela P.; Giraudo, Alejandro R. & Arzamendia, Vanesa

Abstract: Two hypotheses have been proposed to explain the differences among species within present-day communities: the competition-predation hypothesis (CPH) and the deep history hypothesis (DHH). However, the lack of information about the ecology of many species hinders clarification of the role of these different, though not mutually exclusive, hypotheses. We compared ecological data of three species of snakes (genus Thamnodynastes) in their subtropical-temperate geographical distributions, evaluating the reproductive biology, sexual dimorphism, feeding ecology and habitat use of T. hypoconia and T. strigatus, and providing the first ecological data of T. chaquensis. Females attained sexual maturity at larger sizes than males. Unusually for viviparous snakes, males and females had similar body sizes although males had more ventral scales than females. The reproductive cycle of females was seasonal (not annual), with parturition occurring in summer. Males of T. chaquensis and T. strigatus were characterised by continuous reproductive cycles, while males of T. hypoconia showed differences between seasons. All three species mainly fed on amphibians. Thamnodynastes strigatus also fed on fishes, lizards and mammals, T. hypoconia occasionally fed on lizards, while T. chaquensis was an amphibian specialist. Thamnodynastes hypoconia lived in lentic aquatic habitats, T. strigatus was the most aquatic species, and T. chaquensis was the most terrestrial species. We propose that most of the ecological traits examined are phylogenetically conservative within the Tachymenini, supporting the DHH.

Keywords: FEEDING ECOLOGY, NICHE OVERLAP, COMPETITION-PREDATION HYPOTHESIS, HABITAT USE, TACHYMENINI, REPRODUCTION ECOLOGY, DEEP HISTORY HYPOTHESIS

pp. 97-102
Authors: Capula, Massimo; Rugiero, Lorenzo; Capizzi, Dario; Milana, Giuliano; Vignoli, Leonardo; Franco, Daniel; Petrozzi, Fabio & Luiselli, Luca

Abstract: Ectothermic vertebrates depend on ambient temperatures for their activities. Thus, global warming is expected to influence several aspects of their ecology. Here, we use a >20 year (1990–2011) dataset on monthly numbers of roadkills in an area of central Italy in order to document whether the phenology of a Mediterranean population of Western whip snakes (Hierophis viridiflavus) has changed over time. Annual variation of roadkills was correlated to five climatic variables: (i) mean annual air temperature, (ii) mean February air temperature, (iii) mean July air temperature, (iv) yearly number of rainy days, and (v) number of rainstorm days. Increases in mean annual temperature were positively related to the number of roadkills at the early (February and March) and late (December) phases of above-ground activity, but were negatively related to the number of roadkills during summer (June and July). Intriguingly, we documented a shift in the annual mortality peak over the study period, possibly indicating temporal changes of the mating season due to global warming. Increasing mean air temperatures apparently caused an earlier onset of above-ground activity of snakes and delayed hibernation, but reduced the intensity of snake above-ground activity during the hottest and driest period of the year. Rainfall variables had no impact on snake activity.

Keywords: PHENOLOGY, SNAKES, GLOBAL WARMING, ROADKILLS

pp. 103-110
Authors: Herrel, Anthony & van der Meijden, Arie

Abstract: The trade in wildlife is a globally important industry. Amphibians and reptiles are among the most commonly traded animals and this trade has raised concern because of its potential impact on natural populations, animal welfare and the spread of invasive species and emerging infectious diseases. Yet, evaluating the risks involved is difficult due to the lack of quantitative data on the trade. Here, we analyse data on the live reptile and amphibian trade in the USA and the worldwide trade in CITES-listed species over a ten year period. Our analyses show that the trade is dominated by only a few species, with ten species making up the majority of the trade. Moreover, our data show an increase of the contribution of captive bred specimens to the trade in the USA, but not worldwide. Our data do show the presence of several invasive species among those that are traded and bred most. The trade of potential invasive species is problematic and should be more strictly regulated as it may have a global impact on biodiversity and the spread of emerging infectious diseases.

Keywords: HUSBANDRY, IMPORT, CAPTIVE BREEDING, EXPORT, INVASIVE SPECIES, CITES, PET TRADE

pp. 111-122
Authors: Koch, André; Ernst, Nicole; Eidenmüller, Bernd & Kraus, Fred

Abstract: Some monitor lizards are among the least studied of all vertebrate species, being known only from a handful of old voucher specimens in museum collections. This includes tree monitors related to Varanus prasinus (Schlegel, 1839), namely V. telenesetes and the melanistic V. bogerti, which inhabit the Trobriand, D'Entrecasteaux and Louisiade islands off southeastern New Guinea. We provide new data about morphological variation and natural history for V. bogerti supplemented by a detailed description of the colour pattern in hatchlings. The exact distribution range of V. bogerti is still insufficiently known, and a historical record from the Trobriand Islands needs verification. We also discuss the taxonomic status, distribution and origin of the holotype of V. telenesetes, the only known specimen of this taxon, in relation to V. bogerti and V. prasinus. The examination of specimens of V. prasinus from southeastern New Guinea allows a discussion about the putative sympatric occurrence of, and past gene flow between multiple tree monitor species on the D'Entrecasteaux islands in light of climate-induced sea level changes during the Pleistocene. Only further field work and future investigations will yield sufficient answers to the open questions surrounding these rare New Guinean tree monitors.

Keywords: D'ENTRECASTEAUX ISLANDS, MELANISM, REPTILIA, EUPREPIOSAURUS, MILNE BAY, VARANUS PRASINUS SPECIES GROUP, LOUISIADE ISLANDS

pp. 123-128
Authors: Rahman, Shahriar Caesar; Reza, Ahm Ali; Datta, Rupa; Jenkins, Chris L. & Luiselli, Luca

Abstract: Despite the greatest diversity of snakes being in the tropics, detailed ecological studies are rare, especially in tropical Asia. We studied the ecology of a coastal marine homalopsid (rear-fanged, aquatic snakes) assemblage in southeastern Bangladesh. Data were collected on community structure, resource partitioning (diet and habitat), body size and sexual size dimorphism. A total of 653 specimens belonging to three species were collected: Cerberus rynchops (81% of total capture), a medium-sized piscivorous snake, found to be the most abundant species in the study site followed by two crustacean eaters, Gerada prevostiana (13%) and Fordonia leucobalia (6%). The three species were relatively similar in terms of body size but were inconsistent with each other both in terms of morphological patterns and demography characteristics, with sex-ratio being equal in two species but female-biased in G. prevostiana. There was no apparent non-random resource partitioning along the microhabitat axis but a clear pattern of niche partitioning was observed along the food axis. Despite the very unusual evolutionary history of the Homalopsidae inside the group of the Colubroidea, our snake assemblage very closely resembled other communities of snakes worldwide.

Keywords: FOOD NICHE, HOMALOPSIDAE, MUD SNAKES, BANGLADESH, HABITAT, POPULATION STRUCTURE

pp. 129-133
Authors: Ghirardi, Romina; Levy, Michael G.; López, Javier A.; Corbalán, Valeria; Steciow, Mónica M. & Perotti, María Gabriela

Abstract: Infections caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd) have been highlighted as a driver of worldwide amphibian declines. In austral temperate wetlands of South America, anurans are exposed to stressors that can increase the negative effects of emerging infectious diseases. We assessed the presence of Bd infecting anurans from different environments in Patagonia through molecular analysis of skin swabs from 122 individuals belonging to six species. We report Bd in four species, two of which are categorised as endangered, and extend the known distribution of the fungus.

Keywords: PATAGONIA, ANURANS, CONSERVATION, CHYTRIDIOMYCOSIS, ARGENTINA