The British Herpetological Society

The Herpetological Journal is the Society's prestigious quarterly scientific journal. Articles are listed in Biological Abstracts, Current Awareness in Biological Sciences,Current Contents, Science Citation Index, and Zoological Record.


ISSN 0268-0130

Volume 31, Number 1, January 2021 Volume 31, Number 1, January 2021

pdf 01. Comparison of eDNA and visual surveys for rare and cryptic bromeliad-dwelling frogs


Open Access

pp 1-9

Authors: Izabela M. Barata, Richard A. Griffiths, Deborah J. Fogell & Andrew S. Buxton

Abstract: Surveys of rare or cryptic species may miss individuals or populations that are actually present. Despite the increasing use of environmental DNA (eDNA) analysis to survey species in ponds, rivers, and lakes, very few studies have attempted to use eDNA for the detection of species using very small water bodies such as those accumulated within plants. Our aim was to investigate the feasibility of an eDNA sampling method for detecting Crossodactylodes itambe, an endemic bromeliad-dwelling frog from a remote location in Brazil. We collected water samples from 19 bromeliads for which we had observational data from direct visual surveys. We compared occupancy estimated from direct observations with the results from quantitative real-time PCR based eDNA assays. For observational surveys, we used a single season occupancy model. We applied a novel Bayesian occupancy model to estimate occupancy from eDNA samples, as well as false positives and false negatives at different stages of the workflow. eDNA from bromeliad tanks provided reliable estimates, with very low error levels and improved detection when compared to detectability from direct observation. Estimated occupancies using eDNA and visual survey methods were similar. The method is feasible for species restricted to small water bodies and exposed to direct UV radiation, and particularly useful to survey remote locations and confirm species presence. eDNA analysis provides a viable alternative to destructive sampling of bromeliads or direct observation methods that require logistically challenging repeated observations. Therefore, eDNA methods may be widely applicable to sampling programmes of other amphibians that live in plants.

Keywords: bromeliad, eDNA detection, false-positive, amphibian, occupancy, phytotelm

pdf 02. Reconstructions of the past distribution of Testudo graeca mitochondrial lineages in the Middle East and Transcaucasia support multiple refugia since the Last Glacial Maximum


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pp. 10-17

Authors: Oguz Turkozan, Çağaşan Karacaoğlu & James F. Parham

Abstract: A cycle of glacial and interglacial periods in the Quaternary caused species’ ranges to expand and contract in response to climatic and environmental changes. During interglacial periods, many species expanded their distribution ranges from refugia into higher elevations and latitudes. In the present work, we projected the responses of the five lineages of Testudo graeca in the Middle East and Transcaucasia as the climate shifted from the Last Glacial Maximum (LGM, Mid – Holocene), to the present. Under the past LGM and Mid-Holocene bioclimatic conditions, models predicted relatively more suitable habitats for some of the lineages. The most significant bioclimatic variables in predicting the present and past potential distribution of clades are the precipitation of the warmest quarter for T. g. armeniaca (95.8 %), precipitation seasonality for T. g. buxtoni (85.0 %), minimum temperature of the coldest month for T. g. ibera (75.4 %), precipitation of the coldest quarter for T. g. terrestris (34.1 %), and the mean temperature of the driest quarter for T. g. zarudyni (88.8 %). Since the LGM, we hypothesise that the ranges of lineages have either expanded (T. g. ibera), contracted (T. g. zarudnyi) or remained stable (T. g. terrestris), and for other two taxa (T. g. armeniaca and T. g. buxtoni) the pattern remains unclear. Our analysis predicts multiple refugia for Testudo during the LGM and supports previous hypotheses about high lineage richness in Anatolia resulting from secondary contact.

Keywords: Testudo graeca, niche modeling, Last Glacial Maximum, Middle East, Transcaucasia

pdf 03. The effects of two calcium supplementation regimens on growth and health traits of juvenile mountain chicken frogs (Leptodactylus fallax)


Open Access

pp. 18-26

Authors: Christopher J. Michaels, Cheska Servini, Amanda Ferguson, Amanda Guthrie, Stephanie Jayson, Jade Newton-Youens, Taina Strike & Benjamin Tapley

Abstract: The mountain chicken frog (Leptodactylus fallax) is among the 42 % of amphibians threatened with extinction and is dependent upon ex situ populations to recover in the wild. Amphibian captive husbandry is not fully understood and empirical data are required to optimise protocols for each species in captivity. Calcium metabolism and homeostasis are areas of importance in captive husbandry research and have been identified as a challenge in maintaining ex situ populations of L. fallax. We trialled two frequencies (twice and seven times weekly) of calcium supplementation via dusting of feeder insects in two groups of L. fallax juveniles and measured growth and health effects through morphometrics, radiography, ultrasonography and blood and faecal analysis over 167 days, followed by a further 230 days of monitoring on an intermediate diet informed by the initial dataset. We showed that supplementation treatment did not affect growth or health status as measured through blood analysis, radiography and ultrasonography. More frequent supplementation resulted in significantly more radiopaque endolymphatic sacs and broader skulls. Frogs fed more calcium excreted twice as much calcium in their faeces. The intermediate diet resulted in previously lower supplementation frogs approximating the higher supplementation frogs in morphometrics and calcium stores. Comparison with radiographic data from wild frogs showed that both treatments may still have had narrower skulls than wild animals, but mismatching age class may limit this comparison. Our data may be used to inform dietary supplementation of captive L. fallax as well as other amphibians.

Keywords: Amphibia, amphibian, anuran, diet, nutrition, zoo, calcium

pdf 03a. Supplementary Material for 'The effects of two calcium supplementation regimens on growth and health traits of juvenile mountain chicken frogs (Leptodactylus fallax)'


Open Access

Authors: Christopher J. Michaels, Cheska Servini, Amanda Ferguson, Amanda Guthrie, Stephanie Jayson, Jade Newton-Youens, Taina Strike & Benjamin Tapley

pdf 04. A new genus and species of rhinatrematid caecilian (Amphibia: Gymnophiona: Rhinatrematidae) from Ecuador


Open Access

pp. 27-34

Authors: Mark Wilkinson, Robert P. Reynolds & Jeremy F. Jacobs

Abstract: A new genus and species of rhinatrematid caecilian, Amazops amazops gen. et sp. nov., is described based on a single specimen from Orellana, Ecuador collected in 1990. Among other features the new taxon differs from all other rhinatrematid caecilians in having less than four annular grooves interrupted in the region of the vent and in the squamosal contributing to the bony margin of the orbit. A consideration of its distinctive morphology suggests that it is plausible that the new taxon is the sister taxon of all other rhinatrematid caecilians. That the genus is known from a single specimen, and that this is the first new rhinatrematid species from the Andes described for more than 50 years, highlights the poor sampling (collecting) of rhinatrematid caecilians and limited knowledge of their diversity.

Keywords: Andes, biodiversity, computed tomography, morphology, South America, systematics, taxonomy

pdf 05. Make like a glass frog: In support of increased transparency in herpetology


Open Access

pp. 35-45

Authors: Benjamin Michael Marshall  & Colin Thomas Strine

Abstract: Across many scientific disciplines, direct replication efforts and meta-analyses have fuelled concerns on the replicability of findings. Ecology and evolution are similarly affected. Investigations into the causes of this lack of replicability have implicated a suite of research practices linked to incentives in the current publishing system. Other fields have taken great strides to counter incentives that can reward obfuscation –chiefly by championing transparency. But how prominent are protransparency (open science) policies in herpetology journals? We use the recently developed Transparency and Openness Promotion (TOP) Factor to assess the transparency promotion of 19 herpetology journals, and compare the TOP scores to broader science. We find promotion of transparent practices currently lacking in many herpetological journals; and encourage authors, students, editors, and publishers to redouble efforts to bring open science practices to herpetology by changing journal policy, peer-review, and personal practice. We promote an array of options –developed and tested in other fields– demonstrated to counter publication bias, boost research uptake, and enable more transparent science, to enrich herpetological research.

Keywords: accountability, herpetology, journal policy, open science, peer review, reproducibility, transparency

pdf 05a. Supplementary Material for 'Make like a glass frog: In support of increased transparency in herpetology'


Subscription / purchase required

Authors: Benjamin Michael Marshall  & Colin Thomas Strine

pdf 06. Habitat use and age structure of the Fer-de-Lance (Bothrops asper, Viperidae) in Braulio Carrillo National Park, Costa Rica


Open Access

pp. 46-54

Authors: Daniel G. Ramírez-Arce, Alejandro Zúñiga-Ortiz & Dennis K. Wasko

Abstract: The Fer-de-lance or terciopelo (Bothrops asper) inhabits a wide range of environmental conditions and habitats across Central America. While much information on the species is based on anecdotal observations and museum specimens, data collected under natural conditions are more limited. To better document its natural history, this study sought to determine the habitat use and age structure of B. asper in the Quebrada Gonzalez sector of Braulio Carrillo National Park, Costa Rica. Snake surveys were conducted from January 2015 to August 2017 and used to evaluate the population age-class distribution and sex ratio. To evaluate macrohabitat use, surveys were conducted in four habitat types (mature forest, late succession, early succession, and human infrastructure). Microhabitat use was determined by recording several structural variables at each snake location and at random sites. Amphibians were sampled in each habitat type to evaluate the available prey base. Fifty-five individuals were captured, mostly females and juveniles, with five recaptures. Snakes were encountered in all habitat types but most often in early succession forests, which have dense vegetation cover and high prey availability. Snakes selected areas with heavy understory cover when resting, and more exposed sites, often closer to bodies of water, when ambushing prey or moving. Human-disturbed sites were used least. Although snake encounters did tend to correlate with higher amphibian abundance, other factors such as mammalian prey abundance could also influence snake distribution.

Keywords: occupancy, population ecology, habitat selection, behaviour, predator-prey relationship

pdf 07. Comparisons of image-matching software when identifying pool frog (Pelophylax lessonae) individuals from a reintroduced population


Open Access


Authors: Josh Dawson, Connor T. Panter & Inga Zeisset

Abstract: Photographic identification of individual animals is a non-invasive and cost-effective method that can provide
demographic information on wild populations. This study aims to compare two photo-matching algorithms (Wild- ID and I3S-Spot) using a reintroduced population of pool frogs (Pelophylax lessonae) in the UK as a case study. We compared the following parameters 1) sex and age, 2) image quality, 3) image collection size and 4) processing time to evaluate successful image match rates. There were no significant differences in successful match rates found between sex and age groups. Wild-ID was more sensitive to image quality than I3S-Spot. There was a significant negative relationship between image collection size and successful match rates for I3S-Spot, however, no such relationship for Wild-ID. The findings of our study can be used by conservation practitioners to reduce workload and improve accuracy during population monitoring activities.

Keywords: Amphibia, capture-recapture, I3S, photo identification, population monitoring, Wild-ID

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Please note that as from Volume 31 Number 1 (January 2021) on, the Herpetological Journal will be available as an online publication only - the last print edition will be Volume 30 Number 4.   

Aligning with this change, it is now no longer possible to purchase a subscription that includes a print copy of the HJ.  All members who have existing HJ print subscriptions that remain active as at end June 2020 will receive the full four 2020 print editions.  New subscribers or renewals after this time will only have option to subscribe to the online only subscription package.  Subscription pricing has been amended to reflect the content changes.