A new skink (Scincidae: Carlia) from the rainforest uplands of Cape Melville, north-east Australia

Carlia skinks are widespread in New Guinea, Wallacea, and northern and eastern Australia. Most Australian species occur in dry woodlands and savannas or marginal rainforest habitats associated with these. There are two rainforest species, parapatrically distributed in coastal mid-eastern Queensland (C. rhomboidalis) and the Wet Tropics of north-eastern Queensland (C. rubrigularis). These two sister species share a diagnostic morphological trait in having the interparietal scale fused to the frontoparietal. Here I describe a third species in this group, Carlia wundalthini sp. nov., from rainforest uplands of the Melville Range, a rainforest isolate 170 km north of the Wet Tropics. This species is diagnosable on male breeding colouration, morphometrics and scalation. The description of C. wundalthini sp. nov. brings the number of vertebrate species known to be endemic to the rainforest and boulder-fields of Cape Melville to seven. Carlia wundalthini sp. nov. is distinct among these endemics in being the only one that does not appear to be directly associated with rock, being found in rainforest leaf-litter

A new species of Phyllurus leaf-tailed gecko (Lacertilia: Carphodactylidae) from Scawfell Island, mid-east Queensland, Australia

A recent targeted reptile survey of Scawfell Island, in the South Cumberland Group, revealed a species of Phyllurus gecko that could not be morphologically assigned to any described species. Here I describe this as a new species, Phyllurus fimbriatus sp. nov., based on differences in a number of morphometric and scalation traits from congeners. Phyllurus fimbriatus sp. nov. is restricted to deeply-piled boulder habitat under rainforest canopy on Scawfell Island, approximately 50 km offshore from Mackay in mid-east Queensland. A survey in rocky, rainforest habitat on nearby Carlisle Island failed to find the species, and other nearby islands appear to lack sufficiently deep rock outcropping to support the species. Phyllurus fimbriatus sp. nov. is known from two small patches of habitat on Scawfell Island, but it is common within these, and is likely to be found in other suitable habitat patches on the island. Based on assessment of imagery, the total area of habitat occupied may be < 1 km2. The island is protected within South Cumberland National Park, but fire encroachment from adjacent dry sclerophyll habitats, climate change, competition from introduced Asian House Geckos (Hemidactylus frenatus Duméril & Bibron, 1836), and poaching are potential threats

Two new skinks (Scincidae: Glaphyromorphus) from rainforest habitats in north-eastern Australia

Tropical rainforest is largely restricted in Australia to the fairly continuous Wet Tropics region and disconnected patches to the north on Cape York. The Wet Tropics is relatively well explored and studied, whereas the rainforests of Cape York have received less attention due to their remoteness. Here we describe two new species of Glaphyromorphus skinks from rainforest areas on Cape York. The two new species are most similar to each other and to G. fuscicaudis and G. nigricaudis, but both are readily diagnosed on numerous traits. Glaphyromorphus othelarrni sp. nov. is diagnosed from all similar species by its supralabial count (typically 8 vs 7), high number of subdigital lamellae beneath the 4th finger (14-15 vs 85 mm) and slender body shape, low number of subdigital lamellae beneath the 4th toe (17-20 vs generally 20 or more), and head and body pattern. Both species also differ from each other and similar congeners in other aspects of body shape, scalation and colour pattern. Glaphyromorphus othelarrni sp. nov. is restricted to boulder-strewn rainforest of the Melville Range, whilst Glaphyromorphus nyanchupinta sp. nov. is known only from upland rainforest in the McIlwraith Range. We discuss patterns of rainforest vertebrate endemism on Cape York, and the importance of lithorefugia in generating these

A new genus to accommodate three skinks currently assigned to Menetia (Lacertilia: Scincidae)

Menetia timlowi Ingram 1977 has had a chequered generic history due to ambiguity in interpreting its various character states. Ingram (1977) assigned this species to Menetia on the strength of “the long narrow obliquely oriented first supraocular” and “enlarged upper circumoculars”. In doing so, he admitted the possibility that M. timlowi “may in fact be a Carlia” but because “all Carlia, except burnetti, lack fused lower eyelids and have a typically anvil shaped presubocular”, allocating timlowi to Menetia seemed the best available option. Ingram and Covacevich (1988) revisited the generic status of this species when resurrecting Lygisaurus from the synonymy of Carlia to accommodate a group of small leaf-litter dwelling skinks. In proposing the new combination L. timlowi (Ingram 1977), they considered the supraoculars to be transverse whereas Ingram had stated them to be oblique in his original species description

The advertisement call and clutch size of the Golden-capped Boulder-frog Cophixalus pakayakulangun (Anura: Microhylidae)

[Extract] In Australia, the family Microhylidae consists of 19 species of Cophixalus Boettger 1892 and 5 species of Austrochaperina Fry 1912 (Hoskin 2012; Hoskin, submitted). Most of these species have highly localized distributions in the rainforests and boulder-fields of north-east Australia (Zweifel 1985; Hoskin 2004; Hoskin & Aland 2011). Australian microhylid frogs are terrestrial breeders with direct development (Zweifel 1985; Hoskin 2004; Anstis et al. 2011). The natural history of Australia’s microhylids is fairly well known, with the basics of breeding biology such as calls and clutch sizes published for most species (Zweifel 1985; Hoskin 2004; Anstis et al. 2011; Hoskin & Aland 2011; Hoskin 2012; Hoskin, submitted). Hoskin & Aland (2011) described two new species from Cape York Peninsula, C. pakayakulangun and C. kulakula, each restricted to boulder-field areas only 30 km apart but readily distinguished by morphology and genetics. Calls could not be compared because the call of C. pakayakulangun was not known at that time. Clutch information for C. pakayakulangun was also not available at the time of description

Species distribution modelling of the endangered Mahogany Glider (Petaurus gracilis) reveals key areas for targeted survey and conservation

The Mahogany Glider (Petaurus gracilis) is one of the most endangered marsupials in Australia. Its known distribution is an approximately 120 km strip of fragmented coastal woodland in north-east Queensland, from north of Townsville to the Tully area. Records are clustered in a number of well-surveyed areas, with significant areas of lowland habitat unsurveyed. Around 30% of historic records fall in areas that were subsequently cleared for farmland, and ongoing clearing and fragmentation of lowland sclerophyll forest continues within the potential distribution. Resolving the distribution is an urgent requirement to guide conservation but Mahogany Gliders are difficult to detect in the field. Species distribution modelling offers a technique for estimating the fine-scale distribution and for targeting further field survey and conservation efforts. We used known occurrence records (N = 481) to predict the distribution of Mahogany Gliders across the Wet Tropics bioregion. We used climatic, topographic and other environmental predictors to generate distribution models using Maxent and Random Forest algorithms, each with two bias correction methods. The predictions revealed that many unknown populations may exist within the currently defined distribution and in important areas beyond this (e.g. Hinchinbrook Island). There was reasonable congruence between models, and we include syntheses of the models to present the most likely current distribution. The most important predictor variables across the models were precipitation seasonality (high seasonality), elevation (generally <100 m), soil type (hydrosols) and vegetation type (including Eucalyptus and Melaleuca woodlands). Our results identify core habitat and reveal key areas that require targeted field surveys. Importantly, the predicted suitable habitat is highly fragmented and ongoing conservation efforts need to improve habitat connectivity and limit further fragmentation

Camera-trapping density estimates suggest critically low population sizes for the Wet Tropics subspecies of the spotted-tailed quoll (Dasyurus maculatus gracilis)

Accurate estimates of distribution and population density are critical for the management of threatened species. This is particularly pertinent for mammalian predators, whose generally low population density, elusive nature, and large home range requirements make it difficult to detect declines. We aimed to refine population estimates of the northern spotted-tailed quoll (Dasyurus maculatus gracilis) in the Wet Tropics bioregion, to estimate the total number of adults, the likely size of subpopulations across the known distribution of the subspecies, and its associated conservation status. We performed targeted upland camera-trapping surveys from June 2017 to May 2019. To calculate population densities, we used a combination of the number of individuals identified from each survey and the mean maximum distance moved from three life history stages. We then extrapolated these estimates to modelled suitable habitat areas, refined by the camera-trapping surveys. Population sizes for the six defined subpopulations were estimated, and ranged from approximately 5 to 105 individuals. The total population was estimated to be 221 individuals. This total population estimate, and the estimates for each of the subpopulations, are lower than previous published estimates and are cause for concern. Given the low population estimates presented here and unresolved threats driving declines in some subpopulations, we suggest elevation of this subspecies to Critically Endangered under the EPBC Act

Invasive ants reduce abundance of small rainforest skinks

Invasive ants are among the world's most damaging invasive species, often directly or indirectly affecting native fauna. Insecticidal baits are the main method for suppressing or eradicating invasive ant populations, but their use must be considered against potential for unintended effects on native organisms. The invasive yellow crazy ant (Anoplolepis gracillipes) is widespread in the tropics, particularly on islands, where they have displaced a range of invertebrates. Effects of this ant on vertebrates, and in continental ecosystems generally, are less studied. We investigated the effects of yellow crazy ants and bait application on rainforest skinks and their invertebrate prey. We compared skink and skink prey abundance across four replicated rainforest site categories: high and low yellow crazy ant sites had both been baited but differed in yellow crazy ant activity; control sites had never had yellow crazy ants or been baited; and buffer sites had never had yellow crazy ants but had been baited. We recorded significantly lower abundance of two small skink species (Lygisaurus laevis and Saproscincus tetradactylus) in high yellow crazy ant sites compared to all other site categories. The differences persisted even after baiting reduced yellow crazy ant activity by 97.8% +/- 0.04% (mean +/- SD). A larger rainforest skink species (Carlia rubrigularis) was not negatively affected by yellow crazy ant invasion. Skink prey abundance was significantly lower in high yellow crazy ant sites compared to control sites and low yellow crazy ant sites, but not compared to buffer sites. These differences did not persist following baiting. We found no evidence that baiting negatively affects skinks or their invertebrate prey. Our data suggest that yellow crazy ants, but not the bait used to treat them, pose a direct threat to small rainforest skinks

Conservation genomics reveals fine-scale population structuring and recent declines in the Critically Endangered Australian Kuranda Treefrog

The Kuranda Treefrog occurs in tropical north-east Australia and is listed as Critically Endangered due to its small distribution and population size, with observed declines due to drought and human-associated impacts to habitat. Field surveys identified marked population declines in the mid-2000s, culminating in very low abundance at most sites in 2005 and 2006, followed by limited recovery. Here, samples from before (2001–2004) and after (2007–2009) this decline were analysed using 7132 neutral genome-wide SNPs to assess genetic connectivity among breeding sites, genetic erosion, and effective population size. We found a high level of genetic connectivity among breeding sites, but also structuring between the population at the eastern end of the distribution (Jumrum Creek) versus all other sites. Despite finding no detectable sign of genetic erosion between the two times periods, we observed a marked decrease in effective population size (Ne), from 1720 individuals pre-decline to 818 post-decline. This mirrors the decline detected in the field census data, but the magnitude of the decline suggested by the genetic data is greater. We conclude that the current effective population size for the Kuranda Treefrog remains around 800 adults, split equally between Jumrum Creek and all other sites combined. The Jumrum Creek habitat requires formal protection. Connectivity among all other sites must be maintained and improved through continued replanting of rainforest, and it is imperative that impacts to stream flow and water quality are carefully managed to maintain or increase population sizes and prevent genetic erosion

Long distance (>20 km) downstream detection of endangered stream frogs suggests an important role for eDNA in surveying for remnant amphibian populations

Background Globally, amphibian species have suffered drastic population declines over the past 40 years. Hundreds of species are now listed as Critically Endangered, with many of these considered “possibly extinct”. Most of these species are stream-dwelling frogs inhabiting remote, montane areas, where remnant populations are hard to find using traditional surveys. Environmental DNA (eDNA) could revolutionize surveys for ‘missing’ and endangered amphibian populations by screening water samples from downstream sections to assess presence in the upstream catchments. However, the utility of this survey technique is dependent on quantifying downstream detection probability and distances. Methods Here we tested downstream detection distances in two endangered stream frogs (Litoria lorica and L. nannotis) that co-occur in a remote stream catchment in north-east Australia, and for which we know precise downstream distributional limits from traditional surveys. Importantly, the two last populations of L. lorica persist in this catchment: one small (~1,000 frogs) and one very small (~100 frogs). We conducted eDNA screening at a series of sites kilometers downstream from the populations using precipitation from two fixed water volumes (15 and 100 mL) and via water filtering (mean 1,480 L). Results We detected L. nannotis and the small L. lorica population (~1,000 frogs) at most sampling sites, including 22.8 km downstream. The filtration method was highly effective for far-downstream detection, as was precipitation from 100 mL water samples, which also resulted in consistent detections at the far-downstream sites (including to 22.8 km). In contrast, we had limited downstream detection success for the very small L. lorica population (~100 frogs). Discussion The ecological aspects of our study system, coupled with thorough traditional surveys, enabled us to measure downstream eDNA detection distances with accuracy. We demonstrate that eDNA from a small population of approximately 1,000 frogs can be detected as far as 22.8 km downstream from the population. Water filtration is considered best for eDNA detection of rare aquatic species—indeed it was effective in this study—but we also achieved far-downstream detections when precipitating eDNA from 100 mL water samples. Collecting small water volumes for subsequent precipitation in the lab is more practical than filtration when surveying remote areas. Our downstream detection distances (>20 km) suggest eDNA is a valuable tool for detecting rare stream amphibians. We provide recommendations on optimal survey methods