The Herpetological Journal

pp. 213-218
Authors: Pearcy, A. & Wijtten, Z.

Abstract: This paper presents insights into the variety and variability in skull shapes of crocodiles using both traditional and nontraditional measurements within a landmark analysis. Using 159 adult crania of all 23 crocodilian species from the collections of five European museums, we found that the relationship between total skull width and length does not account for the majority of the variation between crocodilian species. We identified measurements between the orbit and premaxillary notch, explaining 90% of the variance, the distance from the orbit to the 5^th maxillary tooth, and Kälin's number 12 (1933) as main focal areas for species differentiation. These measurements usefully define the shape of the crocodilian skull, differentiate between species with good precision, and allow reasonable inferences about function.

Keywords: LANDMARK ANALYSIS, CROCODILES, MORPHOLOGY

pp. 219-225
Authors: de Oliveira, Roberto Baptista; Pontes, Gláucia Maria Funk; Maciel, Ana Paula; Gomes, Leandro Ribeiro & Di-Bernardo, Marcos

Abstract: Information on sexual maturity, reproductive cycle, fecundity and sexual dimorphism of Xenodon dorbignyi was obtained from 537 individuals captured in a 333 ha sand dune area on the north coast of Rio Grande do Sul, Brazil, and from dissection and analysis of gonads of 98 specimens from the same region deposited in scientific collections. Females and males reach sexual maturity at about 260 mm and 220 mm snout–vent length (SVL), respectively. Males reach sexual maturity in their first year, whereas some females mature in their second year. Both sexes reach similar SVL; males have a relatively longer tail, and mature females have a heavier body. Reproduction is seasonal, with vitellogenesis occurring from August to January, mating from August to December, oviposition from November to February, and hatching from January to April. Clutch size varied from three to 10 eggs and was correlated with maternal SVL. The ratio between clutch mass and female total mass varied between 0.19 and 0.42 (>0.30 in 80% of observations).

Keywords: NATURAL HISTORY, SERPENTES, DIPSADIDAE, SEXUAL DIMORPHISM, SOUTHERN BRAZIL, REPRODUCTIVE CYCLE

pp. 227-234
Authors: Bourke, Johara; Busse, Klaus C. & Bakker, Theo M.

Abstract: We demonstrate that Darwin's frogs (Rhinoderma darwinii) show sex differences in dorsal pattern and body coloration. Males possessed higher variability than females, which were mainly brown; two dorsal patterns and a green body colour were found exclusively in males. Males at different reproductive stages differed significantly in body colour and dorsal pattern; brooding males were characterized by being greener. Females, which were almost exclusively brown, were mostly found on brown substrates, whereas males were distributed across brown, green and brown/green substrates. An association between body and substrate coloration suggests crypsis to reduce predation risk.

Keywords: POLYMORPHISM, GENDER, MICROHABITAT, CHILE, TEMPORAL VARIATION

pp. 235-245
Authors: Macip-Ríos, Rodrigo; Brauer-Robleda, Pablo; Zúñiga-Vega, J. Jaime & Casas-Andreu, Gustavo

Abstract: Basic demographic information for turtles in tropical and sub-tropical regions is still scarce. As a consequence, prospective management and conservation plans for these long-lived vertebrates lack the necessary quantitative background for successful implementation. In this study, we used capture–mark–recapture techniques in two populations of the Mexican mud turtle (Kinosternon integrum) located at different elevations in central Mexico. We estimated stage-specific survival, growth, and fecundity rates and constructed a population projection matrix for each population. In the low-elevation population, the finite rate of population growth (λ) was not significantly different from unity, indicating demographic stability. In the high-elevation population, λ was significantly lower than unity, indicating population decline. Survival of adults was the vital rate that contributed most to population persistence in both populations. We discuss our results in the context of demographic patterns of turtle species, emphasizing the differences between the two populations studied and potential conservation implications.

Keywords: CAPTURE-MARK-RECAPTURE, POPULATION DYNAMICS, FRESHWATER TURTLES, POPULATION PROJECTION MATRICES, ELASTICITY ANALYSIS, MAXIMUM LIKELIHOOD ESTIMATION

pp. 247-253
Authors: Jungfer, Karl-Heinz

Abstract: A new species of Osteocephalus (Osteocephalus duellmani) is described from the Ecuadorian part of the Cordillera del Cóndor, an isolated sub-Andean mountain range along the Ecuadorian–Peruvian border. Apparently an endemic to these mountains, it is one of the few species in the genus reaching an altitude of almost 2000 m. It is distinguished from other species in the O. buckleyi complex in the lack of spinous dorsal tuberculation, a relatively small tympanum, uniformly coloured posterior surfaces of the thighs, lack of a row of tubercles on the lower jaw, and smooth fringes on the inner side of finger III and outer edge of finger IV.

Keywords: PERU, OSTEOCEPHALUS BUCKLEYI COMPLEX, OSTEOCEPHALUS DUELLMANI

pp. 255-261
Authors: Menin, M.; Waldez, F. & Lima, A.P.

Abstract: We evaluated the effect of environmental and spatial variables on the distribution of 11 species of anurans in 10,000 ha of non-flooded forest in central Amazonia. Diurnal and nocturnal frog assemblages were sampled in 72 plots using visual and auditory surveys. Distance from stream was the best predictor for species richness and abundance, with an increase in distance resulting in a decrease in number of species and individuals. Three species (Osteocephalus oophagus, Trachycephalus resinifictrix and Vitreorana oyampiensis) were not influenced by environmental predictors and occurred along all environmental gradients. The watersheds did not influence the abundance of the majority of species except Allobates sp., Atelopus spumarius and Leptodactylus rhodomystax. Our results indicate that most species studied occur along the margins of streams, which they also use as dispersal corridors. The removal of forests near streams could lead to local extinctions.

Keywords: DISTRIBUTIONPATTERN, COMMUNITYSTRUCTURE, BRAZIL, ENVIRONMENTALFACTORS, ABUNDANCE, ANURA

pp. 263-265
Authors: Katayama, Motoki

Abstract: The interplay between cannibalism and life-history traits is still poorly understood. This study investigates the relationships between sex, snout–vent length and the amount of ingested conspecific eggs in three populations of sword-tailed newts, Cynops ensicauda popei. The mean number of ingested eggs found per individual was 0.13, 0.22 and 0.31 depending on the population, and females were more cannibalistic than males. Mean body size was negatively related to the mass of ingested conspecific eggs, and positively related to the total number of prey items found. Taken together, this study suggests that the amount of cannibalism is primarily influenced by prey availability and body size.

Keywords: EGG PREDATION, CANNIBALISM, FOOD QUALITY, PREY AVAILABILITY

pp. 267-269
Authors: Oromi, Neus; Brunet, Pau; Taibi, Khaled; Aït Hammou, Mohamed & Sanuy, Delfi

Abstract: Demographic life-history traits of Pelophylax saharicus from the Tiaret region (Algeria) were analysed using skeletochronological methods. Lines of arrested growth (LAGs) were characterized by a weak expression of bone growth marks, similar to other North African populations of the same species and probably due to a short inactivity period in pre-Saharan areas. The age attained (1–8 years) and snout–vent length (21.2–106.8 mm) were different from other North African populations of P. saharicus, suggesting that climatic conditions have a large impact on life-history traits in this species.

Keywords: LINES OF ARRESTED GROWTH, SEMIARID ENVIRONMENT, DEMOGRAPHIC TRAITS

pp. 271-273
Authors: Martin, Leigh J. & Murray, Brad R.

Abstract: We compared three methods of marking individual small frogs for identification in short-term studies (several days) using a model species, Limnodynastes peronii (the striped marsh frog). We performed a manipulative experiment under laboratory conditions to compare retention times of gentian violet, mercurochrome and powdered fluorescent pigment. Gentian violet produced the most durable marks with retention times between two and four days. Mercurochrome was retained for at least one day by all treated frogs. Fluorescent pigment was either not retained at all or for one day at most, which suggests that this marking method may not be reliable for short-term studies where identification is required. No adverse reactions to any of the marking methods were detected in our study. Our findings indicate that gentian violet represents a promising alternative as a minimally invasive marking technique for studies of small frogs requiring only short-term retention of identification marks.

Keywords: MINIMALLY INVASIVE, SHORT-TERM STUDIES, AMPHIBIANS

pp. 275-277
Authors: Meuche, Ivonne & Pröhl, Heike

Abstract: Alternative mating tactics are common in anuran amphibians. Calling males are sometimes parasitized by non-calling satellite males that adopt a conditional strategy associated with a lower reproductive success. In most dendrobatid species, males are highly territorial and use calls to attract females and deter competitors. In this study, a satellite tactic used by Oophaga pumilio males is reported for the first time. The satellite tactic was adopted both by territorial and non-territorial males, and was aimed at attracting females in the territory of calling males. This satellite behaviour seems to be facultative, depending on the ability of males to defend a territory, and on the distribution of receptive females.

Keywords: SATELLITE TACTIC, MATING BEHAVIOUR, POISON-DART FROG, DENDROBATIDAE