The Herpetological Journal

pp. 121-132

Authors: Grisel Navarro Acosta, Diego Baldo, Francisco Kolenc, Claudio Borteiro
& Florencia Vera Candioti

Abstract: Research concerning the early development of anuran tadpoles has sparked new interest, ever since comparative studies
revealed structural and temporal variations of embryonic stages within different taxonomic groups. In this paper we studied
the early ontogeny of five species of the hylid genus Hypsiboas: H. curupi, H. pulchellus, H. riojanus and H. sp. from the H.
pulchellus group, and H. faber from the homonymous group. We analyse the development of typical larval structures (oral
disc), and of embryonic transient structures (external gills, ciliated cells, hatching glands and adhesive glands). The diversity
in structural patterns is mainly related to the number and size of external gills, size of the adhesive glands, ciliation density
and number of labial tooth ridges. In turn, heterochronic shifts mostly concern the time of adhesive gland division, and the
regression of the hatching gland and ciliated cells. In some cases these variations appear to be related with oviposition sites
and environments where embryos and larvae develop. Hypsiboas faber embryos, which develop in small nests outside water
bodies, exhibit the largest hatching gland and large, densely ciliated and highly branched external gills as a possible response
to low oxygen environments. The large and persistent adhesive glands of H. curupi and H. sp. gr. pulchellus might be related
to the development of embryos and larvae in small streams. Within the same intrageneric group, certain embryonic traits
of H. pulchellus (e.g., tooth row formula 2/3, minute external gills, low body ciliation) appear to be paedomorphic regarding
ancestral ontogenies, but the ecological/functional correlation (if any) of these features is uncertain.

Keywords: adhesive glands, ciliation, external gills, hatching gland, oral disc

pp. 133-142

Authors: Brett Lewis, Richard A. Griffiths & John W. Wilkinson

Abstract: Increasing development of natural habitats frequently causes conflict with the conservation of protected species. Consequently, interventions that attempt to mitigate the impact of development are becoming increasingly commonplace. We used four approaches to assess the effectiveness of development mitigation on a species subject to widespread development pressures
in Europe – the great crested newt (Triturus cristatus). Firstly, a systematic evidence review revealed eleven published studies
of great crested newt populations at development sites. None provided conclusive evidence that the mitigation carried out was effective in maintaining populations. Secondly, less than half of 406 mitigation licence project files examined contained reports of results. Of those that did, only 16 provided post-development population assessments. These included one extinct population, and 10 ‘small’ populations. Thirdly, standardised population assessments were carried out at 18 sites in England, at least six years after the initial mitigation was completed. Although newt populations persisted at most of these sites, there was evidence of an overall decline, with extinctions occurring at four sites. Fourthly, although the annual cost of mitigation for great crested newts in England is estimated at between £20-43 million, information on the status of populations and habitats makes it difficult to assess whether this is cost-effective for either conservation or development. The quality and quantity of available data make it difficult to assign reasons for population changes at mitigation sites, but the study highlighted four general issues concerning mitigation practice: (1) presence of non-viable populations pre-mitigation; (2) inadequate mitigation interventions and site management; (3) cumulative impacts of further developments; and (4) emergence of new threats post-mitigation. Nevertheless, it is possible that some mitigation activities may have unforeseen and undocumented benefits, such as providing green spaces and biodiversity enhancement in urban areas.

Keywords: amphibian, conservation, habitat management, impact assessment, salamander

pp. 143-150

Authors: Thiago Maia-Carneiro, Tatiana Motta-Tavares & Carlos Frederico Duarte Rocha

Abstract: Here, we investigate influences of body sizes, ontogeny and body temperatures on components of trophic niche dimensions of syntopic Tropidurus hispidus and T. semitaeniatus lizards in northeastern Brazil. Divergences in body dimensions allowed differential food consumption between the species and within T. semitaeniatus, which may decrease overlaps in niche
dimensions. Ants, termites, beetles and flowers were important food items for both species, as are typically found in Tropidurus.
Tropidurus semitaeniatus consumed more plant material as lizards grew in body size, suggesting that consuming such food
might be nutritionally and energetically advantageous. A relationship between total food volume and body temperature in T.
semitaeniatus may have been associated with requirements for food acquisition and digestion.

Keywords: body size, body temperature, diet, herbivory, niche segregation, ontogeny

pp.151-160

Authors: Anthony Santana Ferreira, Adilson de Oliveira Silva, Breno Moura da Conceição
& Renato Gomes Faria

Abstract: We characterised the diets of a community of lizards in the Caatinga area in the Monumento Natural Grota do Angico (MNGA), Sergipe, Brazil. We evaluated food availability during the wet and dry season, and analysed the stomach contents of 427 individuals from six species, identifying plant material and invertebrates to the taxonomic level of Order. In general, different lizard species had similar diets. Isoptera was the most important prey for Ameivula ocellifera, Gymnodactylus geckoides, Lygodactylus klugei and Brasiliscincus heathi, whereas Formicidae was the most important prey for Tropidurus hispidus and Tropidurus semitaeniatus. Prey consumption by each species in dry and wet seasons was similar with regard to prey categories used, but differed in the most commonly consumed orders (except for Brasiliscincus heathi). There was no significant difference between diet and prey availability, with the exception of Collembola and Acari which were rarely consumed. The limited seasonal differences in lizard diets may reflect the abundance and availability of prey.

Keywords: electivity, semiarid, squamata, trophic ecology

pp. 161-171

Authors: Daniela D.C. Dick, Carsten F. Dormann & Klaus Henle

Abstract: The conservation of amphibians is of increasing relevance due to their ongoing and rapid decline. Alterations of floodplains are a major contributor to these declines in temperate Europe. In this study, we assessed the factors determining the abundance of four anuran species (Rana arvalis, Pelobates fuscus, Bombina bombina and Hyla arborea) in a dynamic floodplain in
Central Europe during two hydrologically markedly differing years. We identified species responses to habitat characteristics using zero-inflated models. Only pond surface area explained the abundances of all species investigated in both years. Pond hydroperiod was the second most informative variable, determining site selection of all species except R. arvalis in both years independent from inter-annual landscape variability. Temporal variability in habitat use was determined by water chemistry and morphology of ponds in the year with frequent floods, whereas aspects of vegetation were more important in the year with the lower water level. Our results underline the importance of accounting for temporal variability of habitat use as facilitated by habitat heterogeneity in conservation planning.

Keywords: amphibians, flood plains, habitat models, landscape dynamics, temporal variability, zero-inflated models

pp. 173-180

Author: Tokio Miwa

Abstract: Relatively few studies have investigated diel activity patterns in amphibians; in particular, such studies focusing on autumn
migration are lacking. I investigated the diel activity patterns during autumn instream migrations (to hibernation and breeding
sites) of Rana sakuraii, an explosive breeding frog, at mountain headwaters in Japan. Successive censuses at 2-h intervals,
over a period of 24 h, were conducted 15 times during 4 years (2001, 2002, 2013 and 2014). The diel activity pattern was not
significantly different between the sexes. It was clearly bimodal nocturnal (almost like a crepuscular type), with the first peak
appearing at 1600–2400 h and the second peak appearing at 0400–0800 h. The diel activity was highly correlated with day
time, but not with water and air temperatures. However, it was controlled primarily by illumination rather than by the day
time, because relatively many frogs migrated even during the day when it was very dark due to overcast or rainy weather and
during the midnight time (0000–0400 h) when the environment was slightly illuminated by moonlight owing to clear weather.
In contrast, the diel activity pattern during the winter breeding migration was clearly unimodal, with the peak at 1600–2400 h,
probably because the ambient temperature during the second peak was too low, even though the illumination was suitable.
The results presented herein demonstrate that R. sakuraii requires an optimum ambient illumination; consequently, its diel
activity shows a bimodal nocturnal pattern.

Keywords: autumn migration, bimodal nocturnal, crepuscular, diel activity, instream migration, Rana sakuraii

pp. 181-187

Authors: David J. Gower, Varad B. Giri, Rachunliu G. Kamei, Oommen V. Oommen, Rahul Khot
& Mark Wilkinson

Abstract: We examined two specimens of short-tailed, unstriped Ichthyophis Fitzinger, 1843 collected in 1949 from the Anamalai
Hills of the Western Ghats of peninsular India. One of these specimens was identified previously as the peninsular Indian I. subterrestris Taylor, 1960, the other as I. sikkimensis Taylor, 1960, a species known otherwise only from Nepal and the Indian states of Sikkim and West Bengal, approximately 2,200 km to the northeast. We find that the two specimens in question are conspecific, that both have been misidentified and that the pair together probably belong to an undescribed species. Our conclusion that I. sikkimensis does not occur in peninsular India removes a major biogeographic anomaly.

Keywords: biogeography, microCT, northeast India, phallodeum, taxonomy, Uraeotyphlus

pp. 189-199

Authors: Eduard Galoyan, Anna Vassilieva & Nikolay Poyarkov Jr.

Abstract: The all-year round pit-fall trap monitoring and natural history observations in Cat Tien National Park (southern Vietnam)
describe patterns of migratory and vocal activities of terrestrial anurans. Vocalisation activity was low during the driest period
of the year and rose explosively after the first strong rains in April (up to 19 species registered), and was high during the rainy
season (May–September), however, decreased abruptly towards its end (October–November). Amphibian migratory activity
changed from the dry to rainy season, generally increasing when average monthly rainfall was higher. Some species started
aestivation in the dry season. However, some species were active during the dry season or even increased migratory activity
at this period of the year. We suggest the existence of two ecological types of forest anurans: aestivating and non-aestivating
species. The average monthly activity of aestivating amphibians coincided with rising rainfall from April to August and reduced
abruptly two months before the dry season started. Juveniles of aestivating species appeared mostly in August and September;
juveniles of non-aestivating anurans were abundant throughout the year.

Keywords: amphibians, breeding, Cat Tien National Park, migratory activity, monsoon, Vietnam

pp. 201-216

Authors: Rick van Veen & Byron S. Wilson

Abstract: The introduced small Asian mongoose (Herpestes auropunctatus) has been widely implicated in extirpations and extinctions of island taxa. Recent studies and anecdotal observations suggest that the nests of terrestrial island species are particularly vulnerable to mongoose predation, yet quantitative data have remained scarce, even for species long assumed to be at risk from the mongoose. We monitored nests of the Critically Endangered Jamaican Rock Iguana (Cyclura collei) to determine nest
fate, and augmented these observations with motion-activated camera trap images to document the predatory behaviour of the mongoose. Our data provide direct, quantitative evidence of high nest predation pressure attributable to the mongoose, and together with reported high rates of predation on hatchling and juvenile iguanas (also by the mongoose), support the original conclusion that the mongoose was responsible for the apparent lack of recruitment and the aging structure of the small population that was ‘re-discovered’ in 1990. Encouragingly however, our data also demonstrate a significant reduction in nest predation pressure within an experimental mongoose-removal area. Thus, our results indicate that otherwise catastrophic levels of nest loss (at or near 100%) can be ameliorated or even eliminated by removal trapping of the mongoose. We suggest that such targeted control efforts could also prove useful in safeguarding other threatened insular species with reproductive strategies that are notably vulnerable to mongoose predation (e.g., the incubation of eggs on or underground).

Keywords: Cyclura collei, Jamaican Iguana, Herpestes auropunctatus, mongoose, IAS trapping, nest predation, reptile conservation

pp. 217-229

Authors: Anna B. Vassilieva, Artem Y. Sinev & Alexei V. Tiunov

Abstract: Trophic differentiation of tadpoles of four anuran species (Hoplobatrachus rugulosus, Microhyla fissipes, M. heymonsi,
Polypedates megacephalus) with different oral morphologies was studied in temporary ponds in a monsoon tropical forest in
southern Vietnam. All tadpole species were found to be omnivorous, including filter-feeding microhylids. Both gut contents analysis and stable isotope analysis provided enough evidence of resource partitioning among coexisting species. Gut contents analysis supported the expected partitioning of food resources by tadpoles with different oral morphologies and showed differences in the food spectra of filter-feeding and grazing species. Stable isotope analysis revealed more complex trophic niche segregation among grazers, as well as amongst filter-feeders. Tadpole species differed mainly in δ13C values, indicating a dependency on carbon sources traceable to either of aquatic or terrestrial origins. Furthermore, tadpoles with generalised grazing oral morphology (P. megacephalus) can start feeding as suspension feeders and then shift to the rasping mode. Controlled diet experiment with P. megacephalus larvae showed a diet-tissue isotopic fractionation of approximately 1.9‰ and 1.2‰ for Δ13C and Δ15N, respectively. In natural habitats, the difference in δ13C and δ15N values between body tissues and gut contents of four tadpole species averaged 2.8‰ and 1.0‰, respectively.

Keywords: Amphibia, aquatic food web, Cat Tien National Park, Microhylidae, mouthparts, Southeast Asia, stable isotopes, trophic shift

pp. 231-234

Authors: Nathan J. Robinson, Kelly R. Stewart, Peter H. Dutton, Ronel Nel, Frank V. Paladino & Pilar Santidrián Tomillo

Abstract: There are two commonly utilised, but distinct, methods for measuring carapace length of leatherback turtles (Dermochelys coriacea). Either the carapace is measured along the central ridge or to the side of the central ridge.
Here, we demonstrate that these two measurements produce differing results. Moreover, we formulate a globally-applicable correction factor to standardise between these two measurements. Standardised curved carapace length measurements from leatherback turtles at nesting sites worldwide generally fit into 3 size categories: small (157.5 cm; Indian: Southwest, Indian: Northeast, and Pacific: West).

Keywords: correction factor, morphology, marine turtles, nesting, Regional Management Units

pp. 235-238

Authors: Mao Jun Zhong, Xiao Yi Wang, You You Huang & Wen Bo Liao

Abstract: Phenotypic flexibility of morphological characters is widespread in the animal kingdom. In the present paper, we investigated altitudinal variation in organ size (heart, lungs, livers, kidneys and digestive tract) in the spotlegged treefrog (Polypedates megacephalus) across three populations along an altitudinal gradient in southwestern China. Both heart and lung mass increased with altitude, and is possibly linked to a lower oxygen supply at high elevations; a higher liver mass suggested the increased need for energy stores. Despite significant differences between populations, we found no distinct cline in the length of the digestive tract according to altitude.

Keywords: altitudinal variation, environmental gradients, organ size, Polypedates megacephalus

Online appendix for 02.Population status of great crested newts (Triturus cristatus) at sites subjected to development mitigation

Online appendix for 11.Standardising curved carapace length measurements for leatherback turtles, Dermochelys coriacea, to investigate global patterns in body size