The Herpetological Journal

pp. 127-137

Authors: Jenny Waters, Jacqueline Rounsavill, Abbie Winter, Linsey Trusal & Mizuki K. Takahashi

Abstract: Road de-icing salt has been used to make winter driving safer. However, its eventual drainage into adjacent water bodies has caused detrimental effects on organisms in those aquatic communities, including amphibians. We used the spotted salamander Ambystoma maculatum as a model species and examined whether there would be additive or interactive effects of road salt, egg predation from wood frog Lithobates sylvaticus tadpoles, and alteration to egg-mass jelly layers on the hatching rate, incubation period, snout-vent length (SVL) and developmental stage of hatchlings. We found neither main nor interactive effects of salt on the measured traits, which contradicts some of the previous studies. The other body of previous studies, however, showed observational and experimental evidence that amphibian populations became locally adapted to saline water. Given the roadside origin of our study animals, our negative results provide insight into the ubiquity of local adaptation to saline water among amphibian populations. We also found that egg predation and the presence of egg-mass jelly layers negatively affected the incubation period, SVL, or development in the predicted manners based on the O2 demand-supply balance within egg masses. These responses might be altered by dissolved salt if populations naive to freshwater salinisation were exposed to saline water.

Keywords: aquatic pollution, community ecology, conservation, larval amphibians, Lithobates sylvaticus

pp. 138-145

Authors: Camila Maria Mendonça da Silva, Diego Anderson Dalmolin†, Laura Kauer Schuck, Camila Fernanda Moser & Alexandro Marques Tozetti

Abstract: Morphology and diet are key factors in the ecology of organisms, determining aspects of the natural history and evolution of the species. In this work, we evaluated the diet-morphology relationship in an anuran population, measuring the influence of morphological traits on the variation in the diet of individuals of Leptodactylus luctator. For this purpose, we collected individuals from a natural grassland habitat in southern Brazil. We analysed the stomach content of individuals and classified the consumed food items up to the classification level of order. We also measured four morphological traits per individual of L. luctator: distance between eyes, relative limb length, relative mouth width (gape) and snout-vent length. We applied Linear Mixed Effect Models to evaluate the relationship of anuran morphological traits, number of prey taxa and volume of consumed prey. We tested the hypothesis that the configuration of predator morphological traits determines variations in prey consumption patterns. Our results indicate that the body size of L. luctator was not directly related to the diet composition but the individuals’ gape is directly and positively related to the number of consumed taxa. This suggests that gape limitation could be a limiting factor in prey selection. The capacity to consume a wide variety of prey taxa could be an advantage in unpredictable environments, especially those with great daily thermal amplitudes such as the subtropical Brazilian grasslands.

Keywords: amphibian, diet, ecomorphology, functional ecology, Leptodactylus luctator

pp. 138-145

Authors: Camila Maria Mendonça da Silva, Diego Anderson Dalmolin†, Laura Kauer Schuck, Camila Fernanda Moser & Alexandro Marques Tozetti

pp. 146-152

Authors: Rick J. Hodges, Clifford Seabrook & Christopher J. Michaels

Abstract: A 15-year data set of reptile observations at corrugated iron refuges was analysed to describe the spatial and temporal associations between species pairs of viviparous lizards Zootoca vivipara, slow worms Anguis fragilis, northern vipers Vipera berus and grass snakes Natrix helvetica. Of the two snake species, only the viper is known as a routine lizard predator. We analysed two variables expressing pairwise reptile associations at refuges. The first analysis was of monthly spatial overlap assessed as the proportion of unique refuge positions used in common, but not necessarily used simultaneously. The second analysis was of a more precise spatial and temporal assessment based on counts of reptile pairs cohabitating at the refuges (i.e. using the same refuges simultaneously). Apart from viviparous lizards paired with either of the two snake species, the frequencies for both variables were either as expected or significantly greater than expected by chance; in particular grass snakes cohabited much more frequently than expected with both vipers (+327%) and slow worms (+218%). In contrast, for the viviparous lizard/viper pair both variables were statistically significantly less frequent than expected by chance - monthly overlap (-35%) and cohabitation (-87%). As viviparous lizards are predated by vipers, cohabiting would be much reduced but the significantly lowered monthly spatial overlap may indicate active avoidance. For the viviparous lizard/grass snake pair the spatial overlap was as expected by chance but, as with vipers, the frequency of cohabiting was significantly less than expected by chance (-75%). These observations are discussed in relation to the known kairomonal responses of this lizard to viper and grass snake deposits. Viper deposits are also believed to act as a kairomone for slow worms, but we found no evidence that they avoided vipers, supporting existing literature showing that V. berus is unlikely to be an important slow worm predator.

Keywords: chalk grassland, cohabitation, corrugated iron refuges, species associations, viper kairomone

pp. 146-152

Authors: Rick J. Hodges, Clifford Seabrook & Christopher J. Michaels

pp. 146-152

Authors: Rick J. Hodges, Clifford Seabrook & Christopher J. Michaels

pp. 153-163

Authors: Roger Meek, Luca Luiselli & Roger A. Avery

Abstract: Urbanisation impacts on both abiotic and biotic characteristics of the environment and is likely to bring new selective pressures on animal species living within these areas. The common European wall lizard Podarcis muralis adapts well to urbanisation and indeed may be described as the archetypical urban lizard. In this paper we investigated some aspects of the demography of two populations of P. muralis from western France, one living in a hedgerow system situated in an agricultural area on the edge of a village and a second in an urban garden. The active year in both populations was from February–March until October–December, the latter in the urban garden where temperatures were higher. Numbers decreased from around June then increased again during September but this varied annually and between populations. Diversity and equality indexes for both populations were high, especially in females, indicating a range of individuals and their frequency of presence. Both populations were therefore stable despite only limited numbers of lizards being present for more than one year. Male lizards with high presence were more frequently seen in the company of females than males that were seen less frequently. Hatchling lizards were seen from June after the spring mating period with a second period of hatchlings appearing during autumn. This supports the notion that females annually deposit two clutches of eggs in the area.

Keywords: demography, lizards, non-invasive sampling, Podarcis muralis, western France

pp. 164-172

Authors: David B. Marquis, Basil L. Mashanga, Benjamin Tapley, Oliver R. Wearn, Olivia Couchman, Rikki Gumbs, Claudia Gray, Nisha Owen & Marcus Rowcliffe

Abstract: Caecilians (Order Gymnophiona) are generalist predators of soil invertebrates, and may therefore play an important role in tropical soil ecosystems. However, their fossorial lifestyle and the associated difficulties in surveying them have caused a deficit in data for the majority of species. We applied a systematic approach and an intensive sampling strategy to an Endangered and evolutionarily distinct caecilian from the Eastern Arc Mountains, the Sagalla caecilian Boulengerula niedeni. We investigated the association between habitat type and caecilian occupancy across its entire range, the Sagalla Hill, Kenya, and explored the relationship between several variables (land use type, surface soil temperature, soil compactness and landowner prediction of caecilian presence) and its presence in different habitats. We found no significant effects of any of the investigated variables in predicting caecilian presence across the Sagalla landscape. Instead, our findings suggest that the species survives at least as well in agricultural landscapes as it does in areas with indigenous vegetation, with an estimated density of around 900 caecilians per hectare. A bimodal distribution of sizes and weights of captured specimens suggests ongoing successful breeding and recruitment. This suggests that there is a case for cautious optimism with regard to the status of B. niedeni. Our work could act as a useful pilot for further, improved caecilian surveys in the Eastern Arc Mountains and beyond, to improve our understanding and conservation of these overlooked fossorial amphibians.

Keywords: amphibian, Gymnophiona, Herpelidae, soil ecology, amphibian conservation, Taita Hills

pp. 164-172

Authors: David B. Marquis, Basil L. Mashanga, Benjamin Tapley, Oliver R. Wearn, Olivia Couchman, Rikki Gumbs, Claudia Gray, Nisha Owen & Marcus Rowcliffe

pp 173-176

Authors: João Miguel Alves-Nunes, Adriano Fellone & Juan Camillo Diaz Ricaurte

Abstract: Reptiles exhibit defensive responses in diverse ways, influenced by situational factors. Snakes, such as the South American rattlesnake Crotalus durissus, display complex defensive responses, adapting tactics based on circumstances when encountering potential predators. Environmental and intrinsic parameters shape snake behaviour during predator encounters. This study employs distinct stimuli to investigate behavioural changes and whether snakes adapt defensive strategies. We compare the behaviours of rattlesnakes before and after an aversive stimulus involving physical contact. Following encounters with higher-risk stimuli, snakes become more defensive.Findings reveal that snakes alter strategies based on threat intensity. This phenomenon might be influenced by the potential cost of defense and prior interactions with predators. The study underscores the intricate nature of snake defensive behaviour.

Keywords: behavioural plasticity, antipredator behaviour, aversive stimulus, behavioural cost, active behaviours

pp 173-176

Authors: João Miguel Alves-Nunes, Adriano Fellone & Juan Camillo Diaz Ricaurte

pp. 177-188

Authors: Gustavo Fernandes Telles Moreira, Barnagleison Silva Lisboa, Marcos Jorge Matias Dubeux, Jessika Maria de Moura Neves, Tamí Mott & Filipe Augusto Cavalcanti do Nascimento

Abstract: Aspects of the biology and natural history of the endemic anuran Crossodactylus dantei remain unknown even almost 30 years since its description. In this study, we describe its larval stage, along with the advertisement and territorial calls, and assess its phylogenetic positioning based on a fragment of the 16S rRNA mitochondrial gene. The larval stage of C. dantei follows the morphological pattern of Hylodidae, corroborating the relatively uniform larval morphology of the family. However, it is still possible to observe characters that distinguish C. dantei from other species in the genus, such as the elliptical body in dorsal view, nostrils located closer to the snout than to the eyes, an elongated pre-nasal arena, and the absence of taenia tecti medialis and taenia tecti transversalis in the chondrocranium. Its advertisement call is characterised by a sequence of about 23 pulsed notes, with ascending amplitude modulation, and has a mean duration of 2.5 seconds, with a dominant frequency of 3356 Hz. The territorial call has a mean duration of 23 seconds, a dominant frequency of 3160 Hz, and two distinct types of notes. Phylogenetic analysis indicated the existence of two main lineages in the genus. Crossodactylus dantei was recovered with high statistical support as a sister species to the clade composed of C. gaudichaudii and C. timbuhy. Furthermore, the group formed by these three species was recovered as the sister lineage of C. trachystomus. In summary, the information presented here represents a significant advance in the knowledge of this enigmatic and rare species of the northern Atlantic Forest, providing baseline data for future ecological and evolutionary studies of this unique frog.

Keywords: tadpole, oral anatomy, chondrocranium, calls, phylogeny, Atlantic Forest

pp. 177-188

Authors: Gustavo Fernandes Telles Moreira, Barnagleison Silva Lisboa, Marcos Jorge Matias Dubeux, Jessika Maria de Moura Neves, Tamí Mott & Filipe Augusto Cavalcanti do Nascimento