The Herpetological Journal

Authors: Griffiths, Richard A.

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Authors: Figueiredo, Jaime & de Jesus Rodrigues, Domingos

Abstract: Pesticides have been implicated as one of the main factors responsible for amphibian population declines. Although Brazil is one of the countries that harbours the largest diversity of amphibians on the planet and is a leader in the use of pesticides, few studies have addressed the effects of these substances on amphibians in Brazil. We evaluated the effect of four herbicides (glyphosate, 2,4-D, picloram and a picloram and 2,4-D mixture) commonly used in the southern Amazon on tadpoles of Rhinella marina and Physalaemus centralis. To address the acute toxicity of each pesticide, we calculated LC50₉₆ values and compared them with values reported for several fish species provide by manufacturers, which are often used to infer toxicity of pesticides in Brazil. To address the chronic effects of each pesticide, we maintained tadpoles from Gosner stage 25 until stage 42 or metmorphosis and tested how fractions of LC50₉₆ (25%, 50%, and 75% of LC50₉₆) affected survival, time to metamorphosis and size of metamorphs of the tadpoles. Picloram and the mixture of picloram and 2,4-D showed the highest acute toxicity (LC50₉₆) among the pesticides tested, with a much higher value than those reported for fish. Survival was affected by different concentrations depending on the type of pesticide, without a standard for chronic toxicity. The time to metamorphosis was reduced only in P. centralis, with 2,4-D at 25 and 50% of the LC50₉₆ concentration. Therefore, with the other pesticides, the tadpoles were not able to accelerate their metamorphosis. The size of the metamorphs was increased or reduced depending on the concentration of the pesticide and the species, and in some cases, it was intermediate concentrations that had the greatest effect. These results indicate the need to reassess the current methods of estimating environmental risk because the effects on amphibian fauna are drastic and there is great expansion of agriculture areas in the Amazon.

Keywords: ECOTOXICOLOGY, PESTICIDES, TADPOLES, AMAZON, AMPHIBIAN

pp. 17-23
Authors: Li, Jiaqi; Zhou, Rong & Liu, Naifa

Abstract: Elevation and related environmental factors is a main factor for life-history variation in ectothermic species. To test if altitude can explain variation in life-history traits in the toad-headed lizard Phrynocephalus vlangalii, we sampled gravid females from three localities (Delingha: elevation 2910m, Daotanghe: 3367m; Maduo: 4257m) and measured parturition time, snout-vent length (SVL) at sexual maturity, female body size and postpartum body condition, litter size, litter mass, relative litter mass (RLM), size and mass of newborn offspring. Females gave birth between 25 July and 28 August, and females from lower elevations were earlier than those from higher elevations. Female SVL at sexual maturity and mean SVL, litter size, litter mass, relative litter mass and offspring size varied among populations, whereas female post-parturition body mass and offspring mass remained invariant. Females from the highest elevation had a greater SVL at sexual maturity, mean SVL and abdominal length. Both litter size and litter mass were positively correlated with female SVL. Females from the higher elevation localities (Maduo and Daotanghe) had a lower RLM than those from the lowest elevation (Delingha). Furthermore, females from the highest elevation produced fewer and larger (SVL but not mass) offspring than those from the other localities. Trade-offs between offspring size and number were detected in Delingha and Daotanghe, respectively, but not in Maduo. At a given level of litter size, offspring size was similar between Delingha and Daotanghe.

Keywords: LIFE-HISTORY TRAITS, OFFSPRING SIZE, LITTER SIZE, AGAMIDAE, MATURITY, PHRYNOCEPHALUS VLANGALII, TRADE-OFF

pp. 25-30
Authors: Beebee, Trevor J.C. & Buckley, John

Abstract: Counting cumulative numbers of spawn strings deposited by female natterjack toads Bufo calamita is widely used in Britain as a surrogate estimator of trends in population size. We analysed long-term data from 20 of the best recorded British natterjack populations to assess the relationship between spawn count and population dynamics. Spawn count, toadlet production and numbers of ponds producing toadlets were all correlated. However, high spawn deposition was more likely the cause of high toadlet production than a converse mechanism in which high toadlet production might subsequently increase adult population size. Good toadlet years did not generally correlate with spawn deposition three years later, the expected delay for cohort maturation. Conversely, new ponds could trigger large increases in spawn deposition within a year of their construction. This situation presumably arose because only a fraction of the available adult females usually breed in any one year. We conclude that although spawn string counts and actual female population size were not demonstrably synonymous, spawn counts probably do reflect relative sizes between populations and temporal trends within them except when numbers of productive ponds also change significantly over short timescales. Individual ponds can remain productive of toadlets for at least 25 years provided the habitat is managed appropriately.

Keywords: SPAWN COUNTS, NATTERJACK TOAD, BUFO CALAMITA, POPULATION ESTIMATION, UK

pp. 31-40
Authors: Gambale, Priscilla G. & Bastos, Rogério P.

Abstract: We investigated the influence of air and water temperature, relative humidity, morphological characteristics and distance between males on call parameters of Physalaemus cuvieri. We also compared advertisement and courtship calls recorded for the species. Field observations were carried out between September 2011 and March 2012, in nine water bodies in the north west of Paraná state, southern Brazil. Males of P. cuvieri emitted advertisement and courtship calls in different social contexts, and all acoustic parameters except dominant frequency differed between types of call. Call duration, minimum frequency and sound pressure level (SPL) of advertisement calls were classified as static properties and other parameters were classified as intermediate properties. All acoustic parameters varied more between males than within males. We observed a negative relationship between air temperature and call duration, and a positive relationship between relative humidity and SPL and dominant frequency. Snout-vent length was negatively correlated with minimum frequency. The distance between individuals was negatively correlated with call duration, maximum frequency and frequency range, and positively correlated with dominant frequency. Changes in acoustic parameters depending on environmental, morphological and social parameters are important to expand the information about the evolution of sexual selection and aggressive interactions.

Keywords: COEFFICIENT OF VARIATION, VOCALISATIONS, ADVERTISEMENT CALL, COURTSHIP CALL, AGGRESSIVE INTERACTIONS

pp. 41-47
Authors: López-Alcaide, Saúl; Nakamura, Miguel; Macip-Ríos, Rodrigo & Martínez-Meyer, Enrique

Abstract: The physiological performance of reptiles is subject to specific body temperature ranges, which are frequently similar between closely-related species even when they inhabit sites with different thermal conditions. Pregnant females should be particularly efficient for thermoregulation because healthy embryos develop at a narrow temperature range, a potential problem in the context of current global warming. To test the idea that pregnant lizards adjust their thermoregulatory behaviour to rising temperatures, we set up an experiment with 40 pregnant Sceloporus adleri and measured daily activity and basking time at different treatments (22, 24, 26 and 28°C) for six consecutive days. Basking time significantly decreased with increasing temperature. Lizards were more active in the earliest two time periods of the day (0800–1030 and 1030–1300 hours) when compared to later hours (1530–1800) for all treatments, although the trend was less pronounced at 24 and 26°C. Unexpectedly, the probability of activity for lizards increased at 28°C. All lizards maintained a body temperature without significant differences across treatments. These results suggest that pregnant S. adleri females are able to adjust their behavioural thermoregulation to different thermal environments in a short period of time to maintain an adequate body temperature for key physiological processes such as development and growth of their offspring.

Keywords: THERMAL TREATMENTS, LABORATORY, REPTILES, CLIMATE CHANGE, ECTOTHERMS

pp. 49-57
Authors: Braz, Henrique B.; Kasperoviczus, Karina N. & Almeida-Santos, Selma Maria

Abstract: Fossorial snakes have attracted little scientific attention in studies of natural history, despite their relevance to capture the range of evolutionary-ecological strategies of snakes. In this study, we examined 62 preserved specimens of Phalotris lativittatus (a member of the fossorial and poorly studied Elapomorphini tribe) to obtain information about sexual dimorphism, reproduction, seasonal activity and diet. Males were smaller than females but had longer tails, larger heads and were more heavy-bodied. Females attained sexual maturity at larger body sizes than males. Reproduction is seasonal in both sexes. Vitellogenesis started in mid-autumn, and peaked from late spring to summer. Oviductal eggs and oviposition were recorded from late spring to early summer, while hatchings occurred from late summer to autumn. Clutch size was low, a recurrent trait in fossorial snakes. Spermatogenesis began in autumn, peaked during spring and testicular quiescence occurred in summer. The ductus deferens contained sperm only in spring, when the sexual segment of the kidneys showed dense secretory granules and males were more active. Thus, we suggest that mating is likely to occur in spring. Diet is specialised in amphisbaenids, and no evidence of ontogenetic shift was detected. This is the first quantitative study on the ecology of an Elapomorphini species.

Keywords: BODY SIZES, ACTIVITY PATTERNS, SEXUAL DIMORPHISM, REPRODUCTIVE CYCLES, ELAPOMORPHINI, FOOD HABITS

pp. 59-64
Authors: Bhupathy, Subramanian; Ramesh, Chinnasamy & Bahuguna, Archana

Abstract: We analysed faecal samples and conducted direct observations to determine the feeding habits of native Indian rock pythons, Python molurus molurus in Keoladeo National Park (KNP), Bharatpur, India from October 2007 to September 2009. Pythons fed throughout the year except winter (December–February). Feeding was related to monthly mean minimum temperature (r=0.423, p<0.05), variation in temperature (r=-0.671, p<0.01) and rainfall (r=0.695,p<0.01), but was not associated with prey abundance, monthly mean ambient temperature or humidity. A wide range of prey species belonging to mammals, birds and reptiles was consumed. This study enhances our knowledge of the diet of the Indian rock python in its native habitat and further defines its feeding ecology.

Keywords: FAECAL ANALYSIS, TROPHIC ECOLOGY, TRICOTAXONOMY, INDIAN ROCK PYTHON

pp. 65-68
Authors: García-Roa, Roberto; Sunyer, Javier; Fernández-Loras, Andrés & Bosch, Jaime

Abstract: The infectious disease chytridiomycosis caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is considered one of the main culprits causing major amphibian declines and extinctions worldwide. It is known to occur on every continent except Antarctica and is particularly damaging to amphibian tropical populations. We studied 18 different amphibian species from three different localities in Nicaragua. Our results confirm the presence of Bd for first time in Nicaragua and involve ten amphibian species corresponding to Bufonidae, Craugastoridae, Hylidae and Ranidae. We additionally record Bd for the first time in four amphibian species: Craugastor lauraster, Dendropsophus microcephalus, Smilisca baudinii and Lithobates brownorum.

Keywords: CERRO JESÚS, VOLC??N MADERAS, DATANL??-EL DIABLO, BD, INFECTIOUS DISEASE, ISLA OMETEPE, CHYTRIDIOMYCOSIS