The Herpetological Journal

Authors: Patricia Marques do A. Oliveira, Carlos A. Navas & Pedro M. Sales Nunes

Abstract: Semi-arid environments impose significant thermal stress on ectotherms, requiring specialised water acquisition strategies. This study investigated the water status of three lizard species from the Caatinga, examining the interaction between environmental factors and physiological adaptations for water acquisition. To achieve this, we combined field data—including body mass, body condition and body temperature—with induced hydration experiments to quantify water uptake. Additionally, environmental factors such as soil and air temperature, as well as humidity, were measured. Ameivula ocellifera exhibited the highest water absorption, potentially reflecting greater dehydration due to its active foraging and sun exposure. Conversely, Tropidurus semitaeniatus absorbed less water, suggesting better hydration, possibly linked to its rocky habitat that may enhance water retention. Soil temperature and humidity significantly influenced the water status of all species, underscoring the role of ectothermy in water regulation. These findings highlight the importance of ecological context and environmental conditions in shaping water-related adaptations in semi-arid lizards.

Keywords: reptiles, brazilian drylands, experimental hydration, body weight

Authors: Thomas W. Fieldsend, Herbert Rösler, Kenneth L. Krysko, Madison E.A. Harman, Stephen Mahony & Timothy M. Collins

Abstract: The red-spotted tokay gecko Gekko gecko (Linnaeus, 1758) is a widely distributed Asian gecko that has established outside of its native range in southern Florida, USA. This study used genotypic and phenotypic data to determine whether multiple, distinct forms of red-spotted tokay gecko are present in southern Florida, as has previously been hypothesised. Analysis of mitochondrial (ND2) and nuclear (RAG-1) sequence data identified two discrete mito-nuclear lineages in southern Florida, and population-level morphological structure was non-randomly associated with mito-nuclear lineage, confirming a weak but significant genotype-phenotype link. Multiple lines of evidence thus indicate the introduction of two distinct forms of tokay gecko to southern Florida.

Keywords: biological invasions, multiple introductions, taxonomy, tokay gecko

AUTHORS: Giulia Simbula, Gianpaolo Montinaro, Tina Grimm & Jan-Dieter Ludwigs

ABSTRACT: Radiotelemetry has emerged as a crucial tool in wildlife biology, enabling researchers to monitor animal movements and behaviours in their natural habitats. While extensively used across various taxa, there remains a scarcity of studies dedicated to optimising radiotelemetry techniques for reptiles, especially small–medium lizard species (50–400 mm total length). In this study, the efficacy of two radio transmitters (Lotek PIP5 and Telemetrie-Service Dessau models) and different attachment methods on sand lizards inhabiting vineyard ecosystems were investigated. We evaluated three harness designs adopted over two years of fieldwork, the Adapted Rappole-Harness (ARH), Shoulder Harness (SH), and Axillary Harness (AH), considering methodological details, attachment longevity, signal range and strength, potential behavioural effects, threats to lizards’ health and survival. Our results indicated that the ARH model was unsuitable, as lizards quickly removed it after few minutes. The SH remained attached for a maximum of 10 days, while the AH lasted up to 17 days, withstanding adverse environmental conditions and terrain abrasion. This study provides valuable insights into optimising radiotelemetry techniques for small–medium reptile species. By considering harness design, attachment location, materials and transmitter shape, researchers can enhance the welfare of tagged individuals and improve the efficiency of telemetry studies. Furthermore, this research underscores the need for standardised guidelines for transmitter attachment in reptiles, promoting animal welfare and advancing scientific understanding in this field. Sharing experiences and collaborating within the scientific community will foster progress in developing effective and ethical transmitter attachment protocols for small–medium reptiles.

Keywords: harness designs, radio-tag, sand lizards, telemetry, transmitters devices

AUTHORS: André Kaufer Leite, Jaqueline Bianque de Oliveira, Moacir Santos Tinôco, Tércio da Silva Melo & Geraldo Jorge Barbosa de Moura

ABSTRACT: Studying the ecological and evolutionary relations between parasites and their hosts is relevant for understanding the biology and conservation of hosts, as it helps to determine which factors influence parasitism, whether intrinsic (sex, age, morphology) or extrinsic (environmental). Glaucomastix abaetensis is an endemic lizard found in the restingas along the northern coast of the state of Bahia, in the north-eastern region of Brazil, and is classified as Endangered. The aim of the present study was to determine the parameters of the parasite ecology of populations of G. abaetensis in two areas with restinga vegetation. Of the 166 individuals studied, 25.3% harboured parasites, with an average infection intensity of 3.63 ± 0.84 (ranging from 1 to 7.6). The results obtained for this species had not been previously documented and may contribute to conservation plans for the species and the ecosystem in which they live, as information on the parasite-host relationship is essential for understanding the interactions of this species within the environment.

Keywords: reptiles, hosts, endoparasites, parasite infection, conservation

Authors: Calvo Rodrigo, Velasco Melina Alicia, Rolón Melisa Celia Jazmin, Martinez Aguirre Tomás, Igor Berkunsky & Kacoliris Federico Pablo

Abstract: This study represents the first application of radio telemetry on the Critically Endangered Valcheta frog Pleurodema somuncurense from Argentina’s Patagonia, aimed at understanding its spatial ecology, daily movements and home range. Six adult individuals were equipped with radio transmitters to assess their activity patterns and habitat use. Average travel distances from sunset to night detection and from sunset to sunrise were 6.47 m (± 4.2) and 6.32 m (± 4.87), respectively, with no significant difference (Student’s t-test, p = 0.42, α = 0.05). Over a complete activity cycle, individuals moved an average of 8.62 metres (SD = 2.2). The estimated home range was 39 m² including an individual with heightened movement, and 30 m² excluding it. Movements ≤ 5 m were categorised as local adjustments, while > 5 m were exploratory migrations, the latter comprising 25.54% of movements in most individuals, though one frog exhibited 56.25%. Despite successful data collection, high mortality and transmitter displacement highlight the technique’s limitations in aquatic anurans. Findings from this study provide valuable data on P. somuncurense’s habitat connectivity needs, informing restoration and conservation efforts across its restricted range. Future studies should consider adjusting the telemetry approach to mitigate the impact on behaviour and survival.

Keywords: connectivity, Somuncura plateau, transmitter, amphibian conservation

AUTHORS: Ling Li, Gang Wang, Songwen Tan, Peng Guo, Bingjun Dong & Yayong Wu

ABSTRACT: Lizards exhibit sexual dimorphism in various phenotypic traits and whole-organism performance (e.g. bite force). The patterns of sexual dimorphism vary among genera and species. The relationship between morphology and function is dynamic, and selective pressures can differentially affect bite performance in different sexes. Here, we analysed sexual dimorphism in morphological traits and bite force, and explored the determinants of bite force between two sexes in the mountain dragon Diploderma batangense from western China. A total of 135 individuals were collected and seven morphological characteristics and bite force were measured. We found a significant male bias in morphology and bite force performance, with males exhibiting larger head size, body size and bite force than females, which may be explained by sexual selection. Results also showed that bite force was positively correlated with head size, with the determinant affecting bite force differing between males (mouth length) and females (head width), which may be related to their different roles in reproduction. This study provides a reference for understanding the ecological adaptability of mountain dragons in the field and lays a foundation for revealing the mechanism of bite force variation between the sexes.

Keywords: bite force, lizards, sexual dimorphism, morphology, sexual selection

Authors: Mickaël Sanchez, Alicia Bonanno, Margot Caubit & Johanna Clémencet

Abstract: The Manapany day gecko Phelsuma inexpectata is endemic to Réunion Island and listed as a Critically Endangered species. Despite high conservation stakes, basic morphological data are scarce. Based on 389 captures across its geographic range, we provide the first large data set on body size allowing estimation of size at sexual maturity. Based on the snout-vent length (SVL) distribution of mature males and females, the transition size between the immature stage and the mature stage is estimated at a minimum of 42 mm SVL. Unambiguous indicators of sexual maturity are observed at a minimum SVL of 42 mm in males and 47 mm in females. Males are significantly larger than females, and both can reach a larger size than previously described in the literature. Finally, based on the temporal distribution of gravid females, we show that the egg production period may begin earlier than previously described in the literature.

Keywords: Manapany day gecko, morphology, reproduction, Réunion Island

AUTHORS: Ling Li, Gang Wang, Songwen Tan, Peng Guo, Bingjun Dong & Yayong Wu

Authors: Mickaël Sanchez, Alicia Bonanno, Margot Caubit & Johanna Clémencet

Authors: Thomas W. Fieldsend, Herbert Rösler, Kenneth L. Krysko, Madison E.A. Harman, Stephen Mahony & Timothy M. Collins

AUTHORS: Pearson McGovern, Edem Eniang, Stephanie N. Ajong, Gift Simon Demaya, Mathias Behangana, Sery Gonedele-Bi, Fabio Petrozzi, Godfrey C. Akani, Julia E. Fa & Luca Luiselli

ABSTRACT: How species interact with their environments is critical to ensuring proper conservation action. Interactions come in many forms, but one of the most basic and least studied for tropical freshwater chelonians seems to be their diet, a proxy for determining generalist versus specialist species. Even less represented in the scientific literature on chelonians are studies of intraspecific variation in diet, specifically dietary differences between the sexes and ontogenetic shifts in diet for large-bodied species. Herein, we investigate the diets of male, female and juvenile (< 25 cm SLC) Trionyx triunguis in both their east and west African range to evaluate differences and measure their dietary generalism. We found ontogenetic and location-based dietary differences.

Keywords: geographical comparison, omnivory, ontogeny, softshell, turtles