Montane Lizard Research Articles

A targeted study to determine the conservation status of a Data Deficient montane lizard, the Eungella shadeskink (Saproscincus eungellensis)

Context Combatting biodiversity loss is often hamstrung by a lack of species-specific knowledge. Species considered Data Deficient (DD) on the IUCN Red List are poorly understood and often neglected in conservation investment, despite evidence they are often threatened. Reptiles have the highest percentage of DD species for any terrestrial vertebrate group. Aims We aimed to assess the conservation status of the DD Eungella shadeskink (Saproscincus eungellensis), which is endemic to Eungella National Park, Queensland, Australia. Methods A combination of a targeted field survey, ecological studies, and species distribution modelling were used. Key results Saproscincus eungellensis typically occurred within 25 m of streams, at elevations between 700 and 1000 m. The species is thigmothermic, with a low active body temperature (~23–26°C) and was predominantly observed on rocks and fallen palm fronds. The species has a highly restricted distribution with an estimated Area of Occupancy of 36 km2 and Extent of Occurrence of 81.7 km2, comprising one location (defined by the threat of climate change) with an estimated 16,352–52,892 mature individuals. The main threats are fire, invasive alien species and climate change, with the species forecast to lose all suitable habitat by 2080 under all climate change scenarios. Conclusions The species meets listing criteria for Critically Endangered under Criterion B of the International Union for Conservation of Nature. Implications Our results support recent studies indicating that some DD species are highly threatened. Our approach provides a template for conducting targeted studies to determine the conservation status of DD species, especially those with restricted ranges.

Seasonal and altitudinal variation in dorsal skin reflectance and thermic rates in a high-altitude montane lizard.

Temperature is one of the most important factors in the life histories of ectotherms, as body temperature has an undeniable effect on growth, activity, and reproduction. Lizards have a wide variety of strategies to acquire and maintain body temperature in an optimal range. The "Thermal Melanism Hypothesis" proposes that individuals with lower skin reflectance can heat up faster as a result of absorbing more solar radiation compared to lighter conspecifics. Therefore, having a darker coloration might be advantageous in cold habitats. Dorsal skin reflectance has been found to change rapidly with body temperature in several lizard species, and it can also vary over longer, seasonal time scales. These variations may be important in thermoregulation, especially in lizards that inhabit areas with a large temperature variation during the year. Here, we study how dorsal reflectance fluctuates with body temperature and varies among seasons. We compared dorsal skin reflectance at three body temperature treatments, and measured thermal rates (i.e., heat and cool rate, thermic lapse, and net heat gain) by elevation (2500-4100m) and seasons (spring, summer, and autumn) in the mesquite lizard, Sceloporus grammicus. Our results show that lizards were darker at high elevations and during the months with the lowest environmental temperatures. The rate of obtaining and retaining heat also varied during the year and was highest during the reproductive season. Our results indicate that the variation of dorsal skin reflectance and thermal rates follows a complex pattern in lizard populations and is affected by both elevation and season.

Accelerating local extinction associated with very recent climate change.

Climate change has already caused local extinction in many plants and animals, based on surveys spanning many decades. As climate change accelerates, the pace of these extinctions may also accelerate, potentially leading to large-scale, species-level extinctions. We tested this hypothesis in a montane lizard. We resurveyed 18 mountain ranges in 2021-2022 after only ~7 years. We found rates of local extinction among the fastest ever recorded, which have tripled in the past ~7 years relative to the preceding ~42 years. Further, climate change generated local extinction in ~7 years similar to that seen in other organisms over ~70 years. Yet, contrary to expectations, populations at two of the hottest sites survived. We found that genomic data helped predict which populations survived and which went extinct. Overall, we show the increasing risk to biodiversity posed by accelerating climate change and the opportunity to study its effects over surprisingly brief timescales.

Range contractions and reduced body mass predicted for endemic skinks of the Cameroon Volcanic Line with future warming

AbstractAimThe vulnerability of montane species to environmental change has been increasingly recognized in recent years. However, most of these species are regionally endemic with restricted distributions, limiting dispersal necessary for avoiding extinction. The outcome of threats posed for montane lizards is further complicated in species exhibiting mass–temperature relationships where body size increases with cooling temperatures, and thus with altitude, causing intraspecific physiological and behavioural differences. We aimed to identify areas suitable for montane endemic skinks of the Cameroon Volcanic Line (CVL) under current and future climates to reveal patterns of persistence and vulnerability based on an intersection of climate and body mass.LocationCameroon Volcanic LineMethodsWe recorded occurrences and measured body mass in the field for two CVL‐endemic skink species. We supplemented occurrences with online repository records. We projected current and future habitat suitability in the region by implementing bioclimatic species distribution models‐based on occurrences. We tested for elevational variations in body mass, and integrated both occurrence and body mass information in a trait‐based model to estimate current and future body mass.ResultsProjected currently suitable habitat for both species was limited to higher elevation regions, which are inhabited by numerous other threatened herpetofauna. We additionally detected Bergmann clines in body mass for both species. Given this variation in body mass, trait model projections covered slightly larger geographical ranges than bioclimatic estimates. Under future warming, both models project substantial contractions in suitable areas, potentially constraining species to mountain tops. Through the trait‐based approach, we further detected potential warming‐induced body mass reductions in projected suitable areas.Main ConclusionsWe demonstrate how combining occurrence records with species trait information in ecological modelling can reveal complementary trends for comprehensive warming impact assessments. Overall, challenges toward the persistence of CVL‐endemic skinks should prompt urgent responses in national conservation management and local community engagement.

Trade-off between thermal preference and sperm maturation in a montane lizard

Temperature is a key abiotic factor that influences performance of several physiological traits in ectotherms. Organisms regulate their body temperature within a range of temperatures to enhance physiological function. The capacity of ectotherms, such as lizards, to maintain their body temperature within their preferred range influences physiological traits such as speed, various reproductive patterns, and critical fitness components, such as growth rates or survival. Here, we evaluate the influence of temperature on locomotor performance, sperm morphology and viability in a high elevation lizard species (Sceloporus aeneus). Whereas maximal values for sprint speed coincides with field active and preferred body temperature, short-term exposure at the same range of temperatures produces abnormalities in sperm morphology, lower sperm concentration and diminishes sperm motility and viability. In conclusion, we confirmed that although locomotor performance is maximized at preferred temperatures, there is a trade-off with male reproductive attributes, which may cause infertility. As a consequence, prolonged exposure to preferred temperatures could threaten the persistence of the species through reduced fertility. Persistence of the species is favored in environments with access to cooler, thermal microhabitats that enhance reproductive parameters.

Habitat suitability or female availability? What influences males’ home-range size in a neotropical montane lizard?

In many species, the shape, size, and location of home ranges depend on the spatial positioning of resources. Therefore, evaluating the resources and conditions related to the space use of individuals can provide crucial information on the species’ ecology and sociobiology. In this study, we evaluated factors shaping the use of space by the lizard Tropidurus montanus M.T. Rodrigues, 1987 and assessed how the distribution of resources can affect the size of the home range and how the quality of the male's home range can influence the number of associated females. We hypothesized that ( i) males with a larger body size would have a higher-quality home range, and ( ii) there would be a positive relationship between the home-range size and home-range quality of males and the number of associated females. Our results suggest that males, females, and juveniles adopt different strategies. While females and juveniles have relatively small home ranges located in more suitable locations, males invest in larger home ranges, including in lower-quality habitat patches. Our results suggest that males increase their home ranges to incorporate resources females prefer, enlarging the number of females in their harems.

Effects of hypoxia on the thermal physiology of a high-elevation lizard: implications for upslope-shifting species

Montane reptiles are predicted to move to higher elevations in response to climate warming. However, whether upwards-shifting reptiles will be physiologically constrained by hypoxia at higher elevations remains unknown. We investigated the effects of hypoxic conditions on preferred body temperatures (Tpref) and thermal tolerance capacity of a montane lizard (Phrynocephalus vlangalii) from two populations on the Qinghai-Tibet Plateau. Lizards from 2600 m a.s.l. were exposed to O2 levels mimicking those at 2600 m (control) and 3600 m (hypoxia treatment). Lizards from 3600 m a.s.l. were exposed to O2 levels mimicking those at 3600 m (control) and 4600 m (hypoxia treatment). The Tpref did not differ between the control and hypoxia treatments in lizards from 2600 m. However, lizards from 3600 m selected lower body temperatures when exposed to the hypoxia treatment mimicking the O2 level at 4600 m. Additionally, the hypoxia treatment induced lower critical thermal minimum (CTmin) in lizards from both populations, but did not affect the critical thermal maximum (CTmax) in either population. Our results imply that upwards-shifting reptiles may be constrained by hypoxia if a decrease in Tpref reduces thermally dependent fitness traits, despite no observed effect on their heat tolerance.

Agonistic behavioural asymmetry in two species of montane lizard that exhibit elevational replacement

In montane systems, closely related species tend to segregate spatially along elevational gradients. The role of biotic interactions, relative to species physiological requirements, in maintaining these distribution patterns is an important question in spatial ecology. Theory suggests that the role of interspecific competition can be significant in the maintenance of elevation replacement distributions. Despite this, there has been limited work investigating factors beyond thermophysiology in determining ranges in temperate montane species. We investigated agonistic (i.e. aggressive) behaviour in response to a simulated intruder (conspecific versus heterospecific 3D printed models) in two sister species of temperate montane lizard, Liopholis guthega and L. montana, from south-eastern Australia. The two species have similar thermal tolerances at an area of distributional overlap between 1600 and 1700 m above sea level, above which L. montana is replaced by the high elevation specialist L. guthega. We found that response to intruder stimuli differed between the two species, with the high elevation L. guthega actively biting both conspecific and heterospecific models, whereas the lower elevation L. montana, never attacked either model type. Our findings provide evidence of asymmetric agonistic response in the two montane reptile species. These findings have important implications for understanding how biological interactions and behaviour, in addition to thermo-physiological data, might mediate landscape scale distribution patterns both now and as environments change in the future. More broadly, our results are not consistent with the widespread idea that low elevation species will inevitably ‘push’ higher elevation species out, as global warming erodes species’ thermal envelopes.

Phylogeny and biogeography of Sumatra´s cloud forest lizards of the genus Dendragama and status of Acanthosaura schneideri.

Lizards of the genus Dendragama are endemic to the highland cloud forests of Sumatra’s Barisan Mountain Range in western Indonesia, and recent studies have uncovered widespread diversity within the genus. Here, a suite of morphological characters and mitochondrial DNA are used to compare three geographically isolated populations of D. boulengeri from (1) Mount Kerinci in Jambi province, (2) Mount Marapi of west Sumatra, and (3) the Karo Highlands of north Sumatra. Additional phylogeographic analyses with two recently described sister species, D. australis and D. dioidema were conducted. Five genetically distinct clades of Dendragama, all distributed allopatrically of one another were identified and some are suspected to inhabit small distributions. Morphological and genetic data confirm the Karo Highlands population D. schneideri (previously Acanthosaura schneideri Ahl, 1926) should be revalidated from the synonymy of D. boulengeri. Dendragama schneideri is endemic to montane forests of the Karo Highlands surrounding Lake Toba in Sumatra Utara province. Pairwise genetic distances of 6–11% separate D. schneideri from congeners. Two distinct clades of D. boulengeri from Mount Kerinci and Mount Marapi were identified, which are 5.0% genetically distant from one another. Using morphological characters, we provide the first key for distinguishing between species of Dendragama. Based on biogeographic patterns and levels of genetic variation it is suspected that at least 18 other isolated cloud forest locations may hold new species or divergent populations of Dendragama but lack survey work. Collectively, these comparisons among populations of montane lizards further elucidate the complex biogeographic history of Sumatra’s montane forest species and the first phylogeny of the genus Dendragama.

Cellular and whole‐organism effects of prolonged versus acute heat stress in a montane, desert lizard

Global climate change involves both prolonged periods of higher-than-normal temperatures and short but extreme heat waves. Both types of temperature increases are likely to be detrimental to ectotherms, and even if such temperature increases do not cause mortality directly, compensating for such temperature increases will likely entail costs to organisms. We tested the effects of prolonged periods of higher-than-average temperatures and short-term, acute heat stress in wild populations of greater short-horned lizards (Phrynosoma hernandesi), a temperate, montane lizard of the Colorado Plateau, UT, USA. We transplanted one group of lizards from a high- to a low-elevation site, exposing them to a prolonged period of warmer temperatures. These lizards, exposed to prolonged periods of higher-than-average temperatures, experienced no change in sprint speed, endurance, or heat shock protein (HSP) production after treatment compared to baseline levels; however, they had lower water content after the transplant to a warmer climate compared to before the transplant. We exposed a second group of lizards to acute heat stress by exposing them to thermally stressful temperatures for 4 h. These lizards, exposed to a short period of acute heat stress, had no change in endurance, water content, or HSP production following acute heat stress; however, lizards exposed to acute heat stress had slower sprint speeds than control lizards. Our results demonstrate that both prolonged temperature increases and acute heat stress, each of which are predicted to occur with climate change, had different cellular and/or whole organismal-level effects on lizards.

RESPONSES OF A MONTANE LIZARD ASSEMBLAGE TO AN EXTENDED DROUGHT

Modern climate change will increase temperatures, as well as the frequency and severity of droughts and wildfires across the semiarid montane regions of the southwestern United States. Predictions of reduced habitat suitability and increases in extinctions precipitated by climate change derive from modeled responses to these conditions, especially increased temperatures. What is often lacking are empirical tests of those modeled predictions. Here I report findings from surveys of montane lizard assemblages during a period of increased temperatures, extended drought, and including a wildfire. I selected survey routes that included upper-elevation limits for western fence lizards (Sceloporus occidentalis), granite spiny lizards (Sceloporus orcuttii), and side-blotched lizards (Uta stansburiana), as well as the lower limits for southern sagebrush lizards (Sceloporus vandenburgianus), to measure the extent to which habitat occupancy shifted as drought conditions changed over 4 years. At the onset of drought, the abundance of all species declined. After initial declines, populations stabilized and I observed recruitment, positive population growth, and elevation shifts with only modest increases in rainfall. Once the drought abated, there were further increases in recruitment and population growth, but a colder winter and heavy snows in 2017 were coincident with declines and range contractions in both western fence and side-blotched lizards on the higher-elevation survey route. There was no indication that any of these species' populations were at risk of local extinctions; rather, shifts at range margins and use of microclimates revealed resilience and mechanisms of how these species might deal with future conditions, including occupying climate refugia.

Climate change, extinction, and Sky Island biogeography in a montane lizard.

Around the world, many species are confined to "Sky Islands," with different populations in isolated patches of montane habitat. How does this pattern arise? One scenario is that montane species were widespread in lowlands when climates were cooler, and were isolated by local extinction caused by warming conditions. This scenario implies that many montane species may be highly susceptible to anthropogenic warming. Here, we test this scenario in a montane lizard (Sceloporus jarrovii) from the Madrean Sky Islands of southeastern Arizona. We combined data from field surveys, climate, population genomics, and physiology. Overall, our results support the hypothesis that this species' current distribution is explained by local extinction caused by past climate change. However, our results for this species differ from simple expectations in several ways: (a) their absence at lower elevations is related to warm winter temperatures, not hot summer temperatures; (b) they appear to exclude a low-elevation congener from higher elevations, not the converse; (c) they are apparently absent from many climatically suitable but low mountain ranges, seemingly "pushed off the top" by climates even warmer than those today; (d) despite the potential for dispersal among ranges during recent glacial periods (~18,000years ago), populations in different ranges diverged ~4.5-0.5million years ago and remained largely distinct; and (e) body temperatures are inversely related to climatic temperatures among sites. These results may have implications for many other Sky Island systems. More broadly, we suggest that Sky Island species may be relevant for predicting responses to future warming.

Thermophysiology, microclimates, and species distributions of lizards in the mountains of the Brazilian Atlantic Forest

Thermophysiological traits, particularly thermal tolerances and sensitivity, are key to understanding how organisms are affected by environmental conditions. In the face of ongoing climate change, determining how physiological traits structure species’ ranges is especially important in tropical montane systems. In this study, we ask whether thermal sensitivity in physiological performance restricts montane lizards to high elevations and excludes them from the warmer environments reported at low elevations. For three montane lizard species in the Brazilian Atlantic Forest, we collect thermophysiological data from lizards in the highest elevation site of each species’ distribution, and ask how well the individuals exhibiting those traits would perform across the Atlantic Forest. We use microclimatic and organism‐specific models to directly relate environmental conditions to an organism's body temperature and physiological traits, and estimate measures of thermophysiological performance. Our findings demonstrate that thermophysiological constraints do not restrict montane lizards to high elevations in this system, and thus likely do not determine the warm boundaries of these montane species’ distributions. Results also suggest that competition may be important in limiting the warm boundaries of the species’ ranges for two of the focal species. These experimental results suggest that caution should be used when claiming that physiology drives patterns of diversity and endemism within montane environments. They also highlight the importance of interdisciplinary experimental studies that bridge the fields of evolution and ecology to improve predictions of biological responses to future environmental shifts.

Escape tactics by a neotropical montane lizard: a comparison of flight responses against natural and nonnatural predators

Prey must judge the level of threat related to a given predator attack to employ the most efficient escape strategy at a low cost. In this context, the capacity of prey to correctly assess the threat from predators might optimise their decision on the strategy employed to flee. We examined the escape behaviour of the montane lizard Tropidurus montanus in response to different types of predatory stimuli. Lizards stimulated by a model of a natural predator ran shorter distances straight towards shelter and spent less time in flight. On the other hand, when exposed to a model of a nonnatural predator, T. montanus performed longer flights in distance and time, running across open and exposed substrates in the view of predators. These results showed that the lizard T. montanus made different escape decisions according to the type of predatory stimulus.

Basking behavior predicts the evolution of heat tolerance in Australian rainforest lizards.

There is pressing urgency to understand how tropical ectotherms can behaviorally and physiologically respond to climate warming. We examine how basking behavior and thermal environment interact to influence evolutionary variation in thermal physiology of multiple species of lygosomine rainforest skinks from the Wet Tropics of northeastern Queensland, Australia (AWT). These tropical lizards are behaviorally specialized to exploit canopy or sun, and are distributed across marked thermal clines in the AWT. Using phylogenetic analyses, we demonstrate that physiological parameters are either associated with changes in local thermal habitat or to basking behavior, but not both. Cold tolerance, the optimal sprint speed, and performance breadth are primarily influenced by local thermal environment. Specifically, montane lizards are more cool tolerant, have broader performance breadths, and higher optimum sprinting temperatures than their lowland counterparts. Heat tolerance, in contrast, is strongly affected by basking behavior: there are two evolutionary optima, with basking species having considerably higher heat tolerance than shade skinks, with no effect of elevation. These distinct responses among traits indicate the multiple selective pressures and constraints that shape the evolution of thermal performance. We discuss how behavior and physiology interact to shape organisms' vulnerability and potential resilience to climate change.

Effects of intense wildfires on the nesting ecology of oviparous montane lizards

In midsummer 2002–2003, intense wildfires raged through the Brindabella Range of south-eastern Australia, including sites where we have studied the ecology of scincid lizards (especially Bassiana duperreyi) for decades. Data-loggers measured the thermal regimes experienced by eggs during these fires (revealing lethally high temperatures in nests under logs in the forest but minimal effect in nests under rocks in clearings). Eggs from forest-clearing nests hatched successfully. Reproductive output of lizards in one area was reduced in the years post-fire (perhaps because of inadequate food [insect] abundance to fuel female reproduction) but soon recovered. The fires reduced vegetation density and thus increased the availability of sun-exposed rocks that serve as potential nest sites. However, the magnitude and duration of these effects differed among sites. Five years after these intense fires, canopy openness (and thus, sunlight penetration to create thermally suitable nest sites) was indistinguishable from pre-fire conditions. Our data reveal strong spatial heterogeneity both in the immediate effects of fire on lizard reproduction and in longer-term post-fire changes in habitat quality. Surprisingly, these intense wildfires had only transitory and local effects on nest-site availability for the heliothermic lizards that we study, but impacts likely were more severe on sympatric taxa that depend upon moist cool microhabitats.

Geographic variation in hybridization and ecological differentiation between three syntopic, morphologically similar species of montane lizards

To understand factors shaping species boundaries in closely related taxa, a powerful approach is to compare levels of genetic admixture at multiple points of contact and determine how this relates to intrinsic and extrinsic factors, such as genetic, morphological and ecological differentiation. In the Australian Alps, the threatened alpine bog skink Pseudemoia cryodroma co-occurs with two morphologically and ecologically similar congeners, P.entrecasteauxii and P.pagenstecheri, and all three species are suspected to hybridize. We predicted that the frequency of hybridization should be negatively correlated with genetic divergence, morphological differentiation and microhabitat separation. We tested this hypothesis using a mitochondrial locus, 13 microsatellite loci, morphological and microhabitat data and compared results across three geographically isolated sites. Despite strong genetic structure between species, we detected hybridization between all species pairs, including evidence of backcrossed individuals at the two sites where all three species are syntopic. Hybridization frequencies were not consistently associated with genetic, morphological or ecological differentiation. Furthermore, P.entrecasteauxii and P.pagenstecheri only hybridized at the two sites where they are syntopic with P.cryodroma, but not at the largest site where P.cryodroma was not recorded, suggesting that P.cryodroma may serve as a bridging species. This study reveals the complex dynamics within a three species hybrid zone and provides a baseline for assessing the impact of climate change and anthropogenic habitat modification on future hybridization frequencies.

Deep Divergences within Liolaemus nigroviridis (Squamata, Liolaemidae) Lineages Associated with Sky Islands in Central Chile.

Evolution of montane species may be strongly influenced by climate oscillations, particularly species distributed in isolated high-elevation areas (sky islands). Chilean topography is exemplified by montane environments including the Andes and Coastal Mountains. To test hypotheses related to genetic divergence associated with sky islands, we explored population genetics and phylogenetic signatures in the montane lizard Liolaemus nigroviridis Müller and Hellmich 1932. We sequenced the mitochondrial cytochrome b for samples collected from six montane areas in central Chile. We found high genetic divergence among populations, congruent with well-supported clades from phylogeny reconstructions. The most recent common ancestor of all samples of L. nigroviridis was dated around the limit of Pliocene-Pleistocene (2.7 Mya), congruent with early vicariance of Andean and coastal populations. Deep lineage divergences suggest that allopatric populations accumulated high nucleotide differences and maintained long periods without gene exchange. We discuss potential taxonomic revisions considering relative genetic divergence.

Temporal germ cell development strategy during continuous spermatogenesis within the montane lizard, Sceloporus bicanthalis (Squamata; Phrynosomatidae)

Sceloporus bicanthalis is a viviparous lizard that lives at higher elevations in Mexico. Adult male S. bicanthalis were collected (n = 36) from the Nevado de Toluca, Mexico (elevation is 4200 m) during August to December, 2007 and January to July, 2008. Testes were extracted, fixed in Trumps, and dehydrated in a graded series of ethanol. Tissues were embedded, sectioned (2 μm), stained, and examined via a light microscope to determine the spermatogenic developmental strategy of S. bicanthalis. In all months examined, the testes were spermiogenically active; based on this, plus the presence of sperm in the lumina of seminiferous tubules, we inferred that S. bicanthalis had year-round or continuous spermatogenesis, unlike most reptiles that occupy a temperate or montane habitat. It was recently reported that seasonally breeding reptiles had a temporal germ cell development strategy similar to amphibians, where germ cells progress through spermatogenesis as a single population, which leads to a single spermiation event. This was much different than spatial development within the testis of other derived amniotes. We hypothesized that germ cell development was temporal in S. bicanthalis. Therefore, we wanted to determine whether reptiles that practice continuous spermatogenesis have a mammalian-like spatial germ cell development, which is different than the typical temperate reptile exhibiting a temporal development. In the present study, S. bicanthalis had a temporal development strategy, despite its continuous spermatogenic cycle, making them similar to tropical anoles.

Predicting the effects of climate change on reproductive fitness of an endangered montane lizard, Eulamprus leuraensis (Scincidae)

A shift in climatic conditions may directly modify critical organismal traits (such as reproductive output and offspring phenotypes), and experimental studies to document such direct effects thus may clarify the impacts of climate change on the species involved. The endangered Blue Mountains Water Skink (Eulamprus leuraensis) exhibits several traits predicted to imperil it under climate change: ectothermy, low reproductive output, specialisation to a restricted habitat type, montane endemicity, and a small geographic range. Congeneric species exhibit temperature-dependent sex determination, increasing potential sensitivity to climate change. We maintained wild-caught female lizards throughout pregnancy under thermal conditions simulating a shift in basking-time availability (3 vs 7 h/day) as might occur under climate change. Females with longer basking opportunities per day gave birth 2 weeks earlier, to slightly smaller offspring, that grew much faster in the first few weeks of life. Importantly, offspring sex ratios were not affected by maternal thermal regimes. Hence, some traits (e.g., offspring size, growth rates, dates of birth) are sensitive to ambient thermal conditions whereas other traits (e.g., offspring sex ratio and sprint speed) are not. On balance, the greatest threat to population persistence for E. leuraensis under climate change is likely to involve indirect effects mediated via habitat degradation (especially, drying-out of the hanging swamps) rather than direct thermal effects on lizard reproductive output or offspring phenotypes.