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A new species of Paramesotriton is described from northern Laos. This represents the first record of Caudata from the country. The species is placed in the genus Paramesotriton based on osteological characters. It differs from all other members of the genus in dorsal color pattern and reduced tongue development.
Lygosoma nototaeniaBoulenger, 1914, and Lygosoma albodorsaleVogt, 1932, previously placed in the genus Sphenomorphus, are redescribed from the three known specimens of each (including two new specimens of the latter species) and transferred to the genus Lipinia. The phenotypically similar genus Scincella is distinguished from Lipinia by an apomorphic feature of the secondary temporal scales. A novel phalangeal condition, shortening of the third phalanx of the fourth toe, is identified in Lipinia cheesmanae and Lipinia longiceps.
A new species of Tropidophis is described from the northern coast of eastern Cuba, in the province of Holguín. It is a small, spotted species previously confused with Tropidophis haetianus of Hispaniola. It differs from that species in being smaller, and in scalation and coloration. It is tentatively placed in the maculatus species group. Tropidophis galacelidus and Tropidophis hardyi are recognized as valid species rather than subspecies of Tropidophis pilsbryi and Tropidophis nigriventris, respectively.
We examined the activity patterns of angulate tortoises, Chersina angulata, on Dassen Island, South Africa, during spring, summer and winter. During typical spring and summer days, C. angulata exhibited a bimodal pattern of activity, with activity being suspended around midday. However, during winter, and on cool and wet summer days, activity was unimodal, peaking around midday. Temporal patterns of activity appeared strongly influenced by environmental factors, particularly temperature. Chersina angulata were never observed to be active at air temperatures below 14.0°C or above 28.7°C. Activity levels were lowest during summer, when animals were active only 1.75% of the time. Brief appearances of available water (usually from condensing fog) during summer, however, resulted in a dramatic increase in activity levels. Males were significantly more active than females during summer and spring, but no significant difference was found between the sexes in winter. Results of this study are principally contrasted with those from a study conducted near the easternmost range of C. angulata, an area that experiences a markedly different climate.
We provide ecological information on Bothrops neuwiedi pauloensis (Amaral, 1925) regarding geographical distribution, habitat use, biometry, feeding habits, and reproduction, based on field studies and analysis of 175 preserved specimens. Bothrops n. pauloensis is endemic to the Brazilian Cerrado, where it occurs in open, seasonally dry savannas. Sexes are dimorphic in body length, relative tail length and relative body mass, but not in relative head length or diet. A wide array of prey, from centipedes to rodents, is consumed, and there is an ontogenetic dietary shift from ectotherms to endotherms. Prey-predator mass ratios ranged from 0.006–0.571. Although prey mass increased with snake mass, large snakes also ate many small prey. There was no difference in relative prey mass between sexes. Reproduction was highly seasonal, with a long vitellogenic period. Embryos were found only from October to December (rainy season). Litter size ranged from 4–20, and was dependent on female size. Although B. n. pauloensis occupies seasonally dry savannas, its ecological characteristics are similar to those described for Bothrops species inhabiting forested habitats.
A new species, closely related to Rhinotyphlops simoni of Jordan and Israel, is described. With this species from the Euphrates River Valley in southeastern Turkey, the R. simoni species group increases to eight taxa (four species in west-central Africa, two species in northeastern Africa, and two species in the Middle East).
Our objective was to develop a long-term monitoring program that quantified anuran population trends in Rhode Island. Because road-based, manual call surveys are widely used in North America to monitor anurans, we assessed the efficacy of using this method to monitor the impact of anthropogenic change of anuran populations in the state. We quantified interspecific variation in calling chronology, calling frequency, and calling intensity at 31 breeding ponds in southern Rhode Island in 1998. Four distinct sampling periods were needed to monitor the seven species we detected. During a species' peak sampling period, males of some species called only sporadically within our 16-min surveys, such as pickerel frogs (Rana palustris), whereas other species called continually [spring peepers (Pseudacris crucifer) and green frogs (Rana clamitans)]. Based on accumulation curves, we suggest that call surveys in Rhode Island be conducted for 10-min at breeding ponds to have a high probability of detecting all species. Assuming we conduct one call survey annually during the four sampling periods, a power analysis estimated that we need to conduct 283 or 690 10-min surveys annually to detect 10% or 5% annual declines, respectively, to monitor most anurans in Rhode Island. Common species that are widespread and call frequently could be monitored with road-based call surveys. However, rarer species or those that call infrequently would be difficult to monitor with call surveys in Rhode Island; therefore other monitoring methods might be more appropriate.
Various aspects of population structure and dynamics of Eleutherodactylus coqui in two forest reserves (Maricao and Guilarte) of the central mountain range of Puerto Rico were determined between July 1997 and June 1998. Adult density ranged from 8–25 animals/100 m2 for the wet season and 3–19 animals/100 m2 for the dry season. Abundance of froglets and juveniles was also greater in the wet season compared to the dry season. By contrast, egg mass counts were greater in the dry season compared to the wet season. Adult body size increased from wet to dry season as population density declined and was found to differ significantly between forests. Adult E. coqui trapped at similar elevations were larger in Guilarte compared to those in Maricao. Average body size for Maricao and Guilarte populations were smaller than those reported for populations in eastern Puerto Rico. Comparing average snout–vent length among frogs from the Luquillo Mountains, Guilarte Forest, and Maricao Forest, a gradient of decreasing body size was observed from east to west across the island.
Growth of the yellow-margined box turtle (Cuora flavomarginata) was studied in northern Taiwan on the basis of recapture data and estimates using the age-carapace length relationship. The growth rate obtained using mark-recapture data from May 1996 to June 2000 was inversely correlated with the body size in both males and females. Growth trends in individuals for whom sex could be determined (i.e., large juveniles and adults) did not significantly differ between sexes. Growth rate in smaller juveniles, although highly variable compared to that of larger individuals, was collectively greater than in the latter. Mean carapace length of females was consistently greater than that of males of the same age. We used nonlinear regression to describe male and female growth trajectories, and the logistic model better fit data on C. flavomarginata than the von Bertalanffy model. Individuals younger than 11 years old occupied no more than 10.3% of the population, 28.8% of which was considered to exceed 18 years of age.
Two new sympatric species of Phrynopus are described from cloud forest (3020–3380 m) of the eastern slopes of the Andes in central Peru (Departamento Huánuco). Both new species appear to be members of the Phrynopus peruanus group.
A new species of Goniurosaurus described from Hainan Island is differentiated from all other species by having a series of enlarged, flat, imbricate scales on the mediolateral portions of the wrist; 37–46 preanal pores as opposed to 18–32 for all other species that have preanal pores; thin as opposed to wide juvenile body bands; faint, whitish colored bands in the caudal interspaces; and caudal bands being incomplete ventrally in adults. A phylogenetic analysis reveals that the new species is the basal member of the Goniurosaurus luii group. It differs from the other members of this group, Goniurosaurus luii and Goniurosaurus araneus, in being less than 107 mm in maximum snout vent length, having a more robust body stature, lacking elongate curved penultimate phalanges, having short robust digits, and having thin dark borders on the body bands. Three species of Goniurosaurus occur on Hainan Island.
We studied the reproductive cycle of Sceloporus “jarrovii” from a temperate environment of the Sierra Madre Oriental in México. Males reached sexual maturity at a smaller snout vent length (SVL; 46 mm) than females (60 mm). Reproductive activity of both sexes was asynchronous, similar to other species inhabiting montane zones. Testes increased in size from June to November and declined rapidly in November. Vitellogenesis occurred from August to October, with ovulation occurring between November and December. Embryonic development was observed from December to early May. There was a significant positive correlation between litter size and female SVL. The reproductive cycle of S. “jarrovii” is similar to other montane species of several families (Anguidae, Scincidae, Phrynosomatidae). Vitellogenesis, ovulation, and gestation time are shorter in northern (Arizona) than southern populations (México). Females from northern populations are larger in SVL and have larger litter sizes than southern populations. Our study suggests that the montane environment (cool temperatures, short growing season, rainfall during the summer) of S. “jarrovii” has played a role in the evolution of a set of reproductive characteristics shared by evolutionarily distant viviparous lizard species inhabiting the montane zone.
Organochlorine compounds (OCs) persist in the environment and can impair development and reproduction in birds, fish, mammals, and other wildlife. However, despite concerns about amphibian population declines and developmental deformities, little is known about the impact of OCs or other pollutants on amphibian populations. In the current study, five polychlorinated biphenyl (PCB)-contaminated wetlands were surveyed for anuran densities relative to four uncontaminated sites. Despite our finding that sediments contained PCB concentrations toxic to some organisms, we found no significant correlation between anuran density or species richness and severity of PCB contamination. In the laboratory, tadpoles and eggs of Rana pipiens and Rana utricularia were negatively affected by PCB concentrations comparable to field levels. Ranid adults and larvae collected from contaminated field sites contained tissue total PCB levels much lower than that of the sediments. Therefore, the apparent lack of population-level impact of PCBs in the field may be explained by limited contaminant accumulation, rather than low physiological sensitivity to chronic PCB exposure.
Observations on post-breeding movements of radio-implanted green frogs (Rana clamitans) revealed that frogs made repetitive forays away from and back to breeding ponds before final migrations to overwintering sites away from the pond. We used a drift fence and radio-transmitters to test the hypothesis that these movements were related to preoverwintering foraging and not overwintering site selection. Movements were oriented directly to habitats away from the pond, the terrestrial habitats had more food than those closer to the pond edge, and frog mass increased during forays away from the pond but declined at the pond. Foray directions were not correlated with migration direction and were considerably shorter than migration distances to overwintering sites. An intense, late season, foraging period is probably necessary for the green frog to rebuild lipid reserves following breeding and to prepare for overwintering.
A new species of long-necked turtle from the Chelodina longicollis group is described from northern Australia; the species Chelodina novaeguineae is restricted to southern New Guinea. The new species differs from its New Guinea counterpart in being a larger species with a broader shell and wider plastron, the skull having paired premaxillae and a narrower parietal ridge, having a single frontal bone, posteriorly partially dividing the parietals, in the form and relationship to the pterygoids of the vomer, and a narrower crista paroccipitalis.