The Herpetological Journal

pp. 233-237
Authors: Du, Wei-Guo; Ji, Xiang & Zhang, Yong-Pu

Abstract: Detecting inter-population differences in life-history traits is the first step in exploring the proximate and ultimate causes of such variation. We measured maternal body size and reproductive output of the lacertid lizard Takydromus septentrionalis from two island populations in eastern China to quantify inter-population variation. We captured female T. septentrionalis from the field and conducted a #common##garden# experiment in the laboratory to measure their reproductive output. The study revealed major divergences in female body sizes, clutch mass and egg mass, but no significant difference in these traits was found between the first clutch and the later clutches. This suggests that the inter-population divergences persisted when the same groups of females were maintained in identical conditions in captivity. In contrast, there were no inter-population differences in size-adjusted fecundities, clutch size and relative clutch masses. Therefore, maternal body size plays an important role in determining female reproductive output in this species, but it does not account for all variation in reproductive traits. The egg size is less variable than the clutch size in each population, which gives support to the optimal egg size theory.

Keywords: FECUNDITY, OFFSPRING SIZE, BODY SIZE, REPRODUCTIVE OUTPUT, INTER-POPULATION VARIATION

pp. 239-247
Authors: Martins, Itamar A.; Almeida, Silvio C. & Jim, Jorge

Abstract: We analysed spatial and acoustic partitioning among four species of Hyla belonging to two species-groups: nana (H. nana and H. sanborni) and rubicundula (H. elianeae and H. jimi). Field activities were conducted at three permanent ponds, from 1998 through 2001. Four attributes of the calling sites were analysed: perch height, distance of the perch from the edge of the pond, type of perch (vegetation) and the individual's position on the perch. There was extensive overlap in the four calling-site variables analysed. However, we found spatial segregation did occur in calling site height and the distance of perches from pond edges. Bioacoustic analyses revealed behavioural differences among species in calling activity, both time of onset and peak calling in chorus. There was acoustic partitioning among species the fundamental frequency of the advertisement calls, principally as a function of the temporal structure (e.g. note duration, rate of note repetition, duration and rate of repetition of the calling pulses). We propose that differences in physical attributes of calling site and in characteristics of calls allow these species to exist in sympatry.

Keywords: ACOUSTIC COMMUNICATION, NICHE BREADTH, CALLING SITE, TREEFROGS

pp. 249-257
Authors: Díaz-Paniagua, C.; Andreu, A. C. & Keller, C.

Abstract: Spur-thighed tortoises, Testudo graeca, in south-western Spain lay 3-4 clutches in shallow nests from April to June. In the present study the incubation temperature of nests laid in field enclosures in April, May and June was monitored over four years. Mean daily temperature throughout incubation averaged 27.9°C, but displayed a wide daily range, with average maximum values around 41°C (also in nests where hatching success was >0), and an absolute maximum of almost 50°C. Early (April) nests displayed lower mean daily temperatures than intermediate (May) and late (June) nests, although all nests reached similar high temperatures during the hottest month (July). Incubation temperatures were affected by nest vegetation cover. Incubation length varied from 67-129 days. Because the length of incubation was negatively correlated with nest temperature, early nests had longer incubation periods than intermediate and late nests. Hatching success averaged 61% and was mainly affected by variables related to maximum temperatures. Thus unsuccessful nests (i.e. no eggs hatching) were associated with higher temperatures or longer exposure to higher temperatures. Differences in hatching or nest success were not related to the nesting month, but might have been influenced by the location of the nest. Lethal temperatures for embryo development were frequently reached during July, therefore vegetation cover of the nest is likely to play an important role in avoiding deleterious nest environments.

Keywords: REPRODUCTIVE SUCCESS, CHELONIA, INCUBATION TEMPERATURE, NESTING

pp. 259-263
Authors: Gower, David J. & Ablett, Jonathan D.

Abstract: The anteroventral scalation patterns of 48 specimens (24 species) of Asian anilioid snakes (Anomochilidae, Cylindrophiidae, Uropeltidae) were examined. Scales were pinned and X-rayed to allow the position of the neck joint to be determined. Asian anilioids have a pattern of anteroventral scalation that prevents application of the standard Dowling system for identifying the first (anteriormost) ventral scale. No repeated pattern is found between anteroventral scalation and the position of the neck joint. Between four and eight post-mentum midventral scales lie anterior to the neck joint, with intraspecific variation occurring by up to two scales. Variation in the position of the neck joint is probably caused by variation in scalation and preservation, and perhaps ontogeny, with fewer midventral scales anterior to the neck joint in larger specimens. We recommend that counts of Asian anilioid ventral scales for taxonomic purposes include all midventral scales between the mental and anal scales. For precise comparisons of precloacal vertebral numbers among Asian anilioids and other snakes, dissections or X-rays are required.

Keywords: METHODOLOGY, MORPHOLOGY, SERPENTES, UROPELTIDAE, SCALATION

pp. 265-271
Authors: Brede, Edward G. & Beebee, Trevor J. C

Abstract: We compared the genetic diversities across eight microsatellite loci of two widespread anurans, Bufo bufo and Rana temporaria, at multiple sites across their western and central European ranges. Bufo bufo consistently exhibited less genetic diversity than R. temporaria. Our evidence infers that this difference is unlikely to be a feature of the specific marker loci used, nor is it a probable consequence of the different phylogeographic histories of B. bufo and R. temporaria. No recent bottlenecks were observed in B. bufo or R. temporaria populations. Both species showed similar levels of differentiation across their European range as estimated by F-statistics, but whereas R. temporaria exhibited isolation by distance effects, B. bufo did not. We suggest that distinct autecological features of the two species are the most likely explanation of the diversity differences, especially more limited historical gene flow among Bufo compared with Rana populations.

Keywords: GENETIC DIVERSITY, AMPHIBIANS, INTERSPECIFIC VARIATION, MICROSATELLITES

pp. 273-280
Authors: D'Cruze, Neil C. & Stafford, Peter J.

Abstract: During an approximately four-week period the ecology and interrelationships of sympatric anoles (Norops spp., Beta Anolis) was studied at a lowland forest site in Belize. The primary aim was to investigate aspects of niche overlap and resource partitioning among species in a typical mainland forest community by quantifying the dimensions of morphology, structural habitat and microclimate. Through characterization of each ecological niche we aimed to determine how these lizards partition the complex resource base and habitat in which they co-exist. Anole species at the study site clearly appear to partition environmental resources along the three major resource axes of microclimate, habitat structure, and probably also prey size, as originally defined by Pianka (1974). Two of the species also show evidence of sexual size dimorphism, indicating that the 'total' niche of these species is further divided into two 'sub-niches' corresponding to each sex. Further experimental manipulations are required, however to demonstrate conclusively whether interspecific competition alone is responsible for structural patterns within anole communities such as this, and also to define the function of differential susceptibility among species to parasites. In the case of three species, a positive correlation between the number of lamellae on the fourth toe of the hind foot and perch height was observed, supporting the notion that lamella number is highly adaptive for an arboreal lifestyle and related to habitat use.

Keywords: SEXUAL DIMORPHISM, ECOLOGICAL NICHE, LIZARD, TOE-PAD MORPHOLOGY

pp. 281-290
Authors: Platt, Steven G.; Rainwater, Thomas R.; Finger, Adam G.; Thorbjarnarson, John B.; Anderson, Todd A. & McMurry, Scott T.

Abstract: We studied the food habits and size-related dietary patterns of Morelet's crocodile (Crocodylus moreletii) in freshwater wetlands of northern Belize (1992–2000). Crocodiles (n=420) were classified as hatchlings, small juveniles, large juveniles, subadults or adults based on total length. Stomach contents were obtained primarily by stomach flushing. Prey items included aquatic and terrestrial insects, arachnids, aquatic gastropods, crustaceans, fish, amphibians, reptiles, birds, and mammals. Based on the percent occurrence of recovered prey items, we concluded that the smallest size classes feed largely on insects and arachnids. Large juveniles broadened their diet to include aquatic gastropods, crustaceans, fish and non-fish vertebrates. Insect and arachnid consumption declined sharply among subadults, and increasing amounts of aquatic gastropods and fish were recovered from this size class. The adult diet consisted mainly of aquatic gastropods, fish and crustaceans. Dietary diversity was greatest among large juveniles and subadults. Conversely, hatchlings and small juveniles had the most specialized (least diverse) diet owing to a reliance on insects and arachnids. Dietary overlap was greatest between adjacent size classes, and lowest between the smallest and largest size classes. We also provide field observations of prey-specific foraging behaviours.

Keywords: ONTOGENETIC DIETARY CHANGE, CROCODILE, FORAGING ECOLOGY, STOMACH FLUSHING

pp. 291-295
Authors: Jesus, José; Brehm, Antonio & Harris, D. James

Abstract: Mitochondrial DNA (12S rRNA, 16S rRNA and cytochrome b) sequences and nuclear sequences (C-mos) were analysed within Lygodactylus thomensis from three volcanic islands in the Gulf of Guinea that have never been connected to the continent. Our aim was to assess interrelationships between the three subspecies to test a recent hypothesis suggesting high rates of mitochondrial DNA (mtDNA) sequence evolution in geckos. Our results indicate, based on mtDNA sequence data, that the three subspecies are genetically differentiated at a level more typically observed between species. However, the forms cannot be differentiated using the nuclear marker C-mos. These results further substantiate the hypothesis of rapid rates of mtDNA sequence evolution in geckos, although the alternative that C-mos is evolving more slowly cannot be discounted. They also suggest that present calibrations for molecular clocks are at the upper limit of divergence over time.

Keywords: PRINCIPE, DWARF GECKO, PHYLOGENY, SAO TOMEACUTE, ANNOBON, GENETIC ANALYSIS

pp. 297-303
Authors: Araújo, Márcio S. & Martins, Marcio

Abstract: The genus Bothrops encompasses at least six evolutionary lineages that show a great diversification in macro and microhabitat use. We studied the defensive behaviour of one species of each of five lineages within the genus Bothrops : B. alternatus, B. jararaca, B. jararacussu, B. moojeni and B. pauloensis. Specifically, we investigated if this diversification in habitat use was accompanied by a similar divergence in the characters related to defensive behaviour in the genus. Eight behavioural categories were recorded, five of which may be classified as #threatening# (strike, tail vibration, head and neck elevation, dorsoventral body compression and body thrashing); two as #escape# (locomotor escape and cocking); and one as #cryptic# (head hiding). We observed significant differences in four behavioural categories. We also detected a significant difference in the way species elevated their head and neck. Tail vibration and strikes were the most common behaviours presented, and snakes that displayed their tails struck more frequently than those that did not display. A reconstruction of characters related to defensive behaviour on a phylogeny of Bothrops indicated an increase in the use of dorsoventral body compression in the groups alternatus and neuwiedi, which may be associated with the invasion of open areas by these lineages.

Keywords: COMPARATIVE METHOD, EVOLUTION OF BEHAVIOUR, CROTALINAE, DEFENSIVE TACTICS

pp. 305-313
Authors: Guo, Peng & Zhao, Er-Mi

Abstract: The relationships of nine Asian pit vipers are discussed using a comparison of skull morphology. Protobothrops xiangchengensis shares more characters with other Protobothrops species than with the other genera. It is morphologically distinct from P. mucrosquamatus. Zhaoermia mangshanensis shows many similarities with the members of the genus Protobothrops, supporting its close relationship with Protobothrops. Ovophis monticola is unique in several skull characters among the species examined. The relationships indicated by skull morphology between Viridovipera stejnegeri, V. yunnanensis and Cryptelytrops albolabris are consistent with their previous reclassification based on molecular results and hemipenial comparison.

Keywords: TRIMERESURUS, TAXONOMY, MORPHOMETRICS, SNAKE

pp. 315-331
Authors: Mariaux, Jean & Tilbury, Colin R.

Abstract: The pygmy chameleons of the Eastern Arc Range forests in Tanzania are reviewed on the basis of known and newly collected material. Two new species belonging to Rhampholeon (Rhinodigitum) and one to Rh. (Rhampholeon) from the Pare, Nguru and Mahenge Mountains are described. The status and distribution of the other species known in the area are reviewed, and an identification key is provided. The phylogenetic relationships between these taxa are discussed on the basis of small and large mt-rDNA subunits sequences and the relative importance of some morphological characters is evaluated. Hypotheses about the evolution of the group in the area are presented.

Keywords: BIOGEOGRAPHY, BIODIVERSITY HOTSPOT, RHAMPHOLEON, RIEPPELEON, MOLECULAR SYSTEMATICS

pp. 333-336
Authors: Smith, J. M.; Buchanan, J.; Downie, J. R. & Riehle, M. O.

Abstract: The jumping performance of Mannophryne trinitatis (Anura: Dendrobatidae), assessed by the parameters of take-off angle, height, length and speed, did not differ significantly between females and males, whether or not males were transporting larvae or had just deposited their larvae. The results are discussed in the context of the possible costs of larval transportation in dendrobatids.

Keywords: LARVAL TRANSPORT, TRINIDAD, REPRODUCTIVE COSTS