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Ecosystem disturbance is increasing in extent, severity and frequency across the globe. To date, research has largely focussed on the impacts of disturbance on animal population size, extinction risk and species richness. However, individual responses, such as changes in body condition, can act as more sensitive metrics and may provide early warning signs of reduced fitness and population declines. We conducted the first global systematic review and meta‐analysis investigating the impacts of ecosystem disturbance on reptile and amphibian body condition. We collated 384 effect sizes representing 137 species from 133 studies. We tested how disturbance type, species traits, biome and taxon moderate the impacts of disturbance on body condition. We found an overall negative effect of disturbance on herpetofauna body condition (Hedges' g = −0.37, 95% CI: −0.57, −0.18). Disturbance type was an influential predictor of body condition response and all disturbance types had a negative mean effect. Drought, invasive species and agriculture had the largest effects. The impact of disturbance varied in strength and direction across biomes, with the largest negative effects found within Mediterranean and temperate biomes. In contrast, taxon, body size, habitat specialisation and conservation status were not influential predictors of disturbance effects. Our findings reveal the widespread effects of disturbance on herpetofauna body condition and highlight the potential role of individual‐level response metrics in enhancing wildlife monitoring. The use of individual response metrics alongside population and community metrics would deepen our understanding of disturbance impacts by revealing both early impacts and chronic effects within affected populations. This could enable early and more informed conservation management. [ABSTRACT FROM AUTHOR]

Australia hosts approximately 10% of the world's reptile species, the largest number of any country. Despite this and evidence of widespread decline, the first comprehensive assessment of the conservation status of Australian terrestrial squamates (snakes and lizards) was undertaken only recently. Here we apply structured expert elicitation to the 60 species assessed to be in the highest IUCN threat categories to estimate their probability of extinction by 2040. We also assessed the probability of successful reintroduction for two Extinct in the Wild (EW) Christmas Island species with trial reintroductions underway. Collation and analysis of expert opinion indicated that six species are at high risk (>50%) of becoming extinct within the next 20 years, and up to 11 species could be lost within this timeframe unless management improves. The consensus among experts was that neither of the EW species were likely to persist outside of small fenced areas without a significant increase in resources for intense threat management. The 20 most imperilled species are all restricted in range, with three occurring only on islands. The others are endemic to a single state, with 55% occurring in Queensland. Invasive species (notably weeds and introduced predators) were the most prevalent threats, followed by agriculture, natural system modifications (primarily fire) and climate change. Increased resourcing and management intervention are urgently needed to avert the impending extinction of Australia's imperilled terrestrial reptiles. The first comprehensive assessment of conservation status for Australian terrestrial squamates was undertaken only recently. We used structured expert elicitation to complement and extend this work by identifying the species in most immediate risk of extinction. Of the 60 species assessed, six had high likelihoods of extinction (>50%) in the next 20 years, and up to 11 species could be lost within this timeframe without substantial improvements to current management regimes. Increased resourcing and management intervention are urgently needed to avert future extinctions of Australia's reptiles. [ABSTRACT FROM AUTHOR]

Aim: The aim was to determine how reptile populations respond to anthropogenic habitat modification and determine whether species traits and environmental factors influence such responses. Location: Global. Time period: 1981–2018. Major taxa studied: Squamata. Methods: We compiled a database of 56 studies reporting how habitat modification affects reptile abundance and calculated standardized mean differences in abundance (Hedges' g). We used Bayesian meta‐analytical models to test whether responses to habitat modification depended on body size, clutch size, reproductive mode, habitat specialization, range size, disturbance type, vegetation type, temperature and precipitation. Results: Based on 815 effect sizes from 376 species, we found an overall negative effect of habitat modification on reptile abundance (mean Hedges' g = −0.43, 95% credible intervals = −0.61 to −0.26). Reptile abundance was, on average, one‐third lower in modified compared with unmodified habitats. Small range sizes and small clutch sizes were associated with more negative responses to habitat modification, although the responses were weak and the credible intervals overlapped zero. We detected no effects of body size, habitat specialization, reproductive mode (egg‐laying or live‐bearing), temperature or precipitation. Some families exhibited more negative responses than others, although overall there was no phylogenetic signal in the data. Mining had the most negative impacts on reptile abundance, followed by agriculture, grazing, plantations and patch size reduction, whereas the mean effect of logging was neutral. Main conclusions: Habitat modification is a key cause of reptile population declines, although there is variability in responses both within and between species, families and vegetation types. The effect of disturbance type appeared to be related to the intensity of habitat modification. Ongoing development of environmentally sustainable practices that ameliorate anthropogenic impacts is urgently needed to prevent declines in reptile populations. [ABSTRACT FROM AUTHOR]

Managing agricultural landscapes for biodiversity conservation is increasingly difficult as land use is modified or intensified for production. Finding ways to mitigate the negative effects of agriculture on biodiversity is therefore critical. We asked the question: How do remnant patches, paddock types and grazing regimes influence reptile assemblages in a grazing landscape?, At 12 sites, we surveyed reptiles and environmental covariates in remnant woodland patches and in four paddock types: (i) grazed pasture, (ii) linear plantings, (iii) coarse woody debris (CWD) added to grazed pasture and (iv) fences between grazed pasture. Each site was either continuously or rotationally grazed., Remnant vegetation and other vegetation attributes such as tree cover and leaf litter greatly influenced reptiles. We recorded higher reptile abundance and species richness in areas with more tree cover and leaf litter. For rare species (captured in ≤4 sites <70 captures), there were 5·7 more animals and 2·6 more species in sites with 50% woody cover within 3 km compared to 5% woody cover., The abundance and richness of rare species, and one common species differed between paddock types and were higher in linear plantings and fence transects compared to CWD and pasture transects., Synthesis and applications. Grazed paddocks, particularly those with key features such as fences and plantings can provide habitat for reptiles. This suggests that discrete differentiation between patch and matrix does not apply for reptiles in these systems. Management to promote reptile conservation in agricultural landscapes should involve protecting existing remnant vegetation, regardless of amount; and promote key habitat features of trees, leaf litter and shrubs. Establishing plantings and fences is important as they support high numbers of less common reptiles and may facilitate reptiles to move through and use greater amounts of the landscape. [ABSTRACT FROM AUTHOR]

Invasive predators can dramatically alter ecosystems through both direct predation and indirect effects such as tropic cascades. However, most examples of top-down effects of invasive predators in terrestrial systems stem from islands or similar low-diversity ecosystems. Snakes are an emerging guild of damaging invasive predators, but demonstration of ecosystem-level impacts of invasive snakes are limited to the single case of the brown treesnake on Guam., Invasive Burmese pythons are firmly established in southern Florida and have been linked to severe (80-100%) declines of several previously common mammal species (e.g. raccoons, opossums and rabbits). Specifically, spatiotemporal patterns of mammal declines in the Everglades mirror the spread of pythons and experimental reintroductions of rabbits to areas where they had been extirpated failed due to high (77% of mortalities) rates of predation by pythons., I evaluated the potential indirect effects of pythons on the nesting success of oviparous species by monitoring artificial turtle nests ( N = 183) at 13 sites across the expanding range of the python population. I documented few mammals and low rates of nest predation (average score = 1·5 on a 1-5 scale) in the southern Everglades where pythons have been established the longest, intermediate (average score = 2·3) rates of nest predation at recently invaded sites, and very high (average score = 4·6) rates of nest predation at sites with few or no pythons. These findings represent the first documentation of potential indirect effects of pythons on non-prey species, and suggest that loss or decline of mammals is resulting in trophic cascades that threaten the Everglades ecosystem., Synthesis and applications. My results suggest that an introduction of non-native apex predators can result in trophic cascades that alter even complex, continental ecosystems. The Burmese python invasion of South Florida shows remarkable parallels with the catastrophic case of the brown treesnake in Guam, but in some ways is even more worrisome. Documentation of both strong direct impacts on prey and potential indirect effects on Everglades' ecosystems within 15 years after being recognized as established emphasizes the need to integrate python management into restoration of the Greater Everglades Ecosystem. More broadly, non-native snakes warrant significant attention for their potential to become damaging invasive species. [ABSTRACT FROM AUTHOR]

The effect of isolation and the importance of dispersal in establishing and maintaining populations in fragments of remnant habitat remain poorly understood. Nevertheless, environmental connectivity is likely to be important for ensuring the long-term preservation of biodiversity in extensively cleared landscapes. In this study, we compared reptile communities in large conservation parks with those in small woodland remnants 6.5-12 km from the parks, on the Eyre Peninsula, South Australia, Australia. We assessed the impact of fragmentation on the abundance, richness and habitat preferences of reptiles, and examined whether connection to linear roadside vegetation altered reptile communities in small woodland remnants. Of the 31 reptile species, 12 were restricted to conservation parks and six to habitat fragments in farmland. There was a substantial reduction in reptile species richness and abundance in farmland fragments. Direct connection of remnant vegetation to roadside corridors did not affect abundance of common species in the farmland fragments, although species richness was lower in isolated remnants in one of our two study regions. The habitat preference of the scincid lizard Menetia greyii differed between farmland fragments, where they were regularly found on dunes and roadsides, and conservation parks, where they were rare and not detected on dunes. We suggest that habitat fragmentation may have altered interspecific interactions, enabling an expansion of habitat use in the farming landscape. Significantly lower abundance of four common species in farmland settings compared with reserves indicated that existing corridors and small fragments provide inadequate connectivity over larger distances. To counter this effect, large reserves may need to be less than 10 km apart. [ABSTRACT FROM AUTHOR]

Species need to disperse at a broad range of spatial scales, the recognition of which has spawned programmes such as Wildlands and WildCountry that aim to restore large-scale connectivity. To achieve connectivity, a first step is to understand how wildlife uses existing remnants. In this study we examine the effect of remnant isolation and condition on the reptile fauna of fragmented mallee habitats in southern Australia. In three replicate landscapes we use pitfall traps to survey reptiles in five landscape elements: Conservation Park, connected, disconnected and isolated fragments, and the agricultural matrix. Reptile species richness, abundance, abundance of snakes, skinks and the 10 most common species had no significant association with landscape elements, excluding the matrix. This was despite a substantial reduction in plant species richness in the fragments, particularly of shrubs. Only seven individual reptiles were captured in the matrix, most on one site with deep sandy soils. The farmland on clay soils appeared to be relatively impermeable for reptiles, although four species could traverse 100 m of cleared sand-dune. The lack of an isolation effect suggests that populations in remnants are persistent, or that occasional dispersal by common reptiles maintains populations. In contrast with common species, fewer rare species were captured in remnants compared with the Conservation Park, implying that some species may be entirely excluded from the remnants. Our study suggests that the spatial configuration and condition of the fragments sustain populations of many common reptile species. Remnants will therefore be invaluable as attempts are made to restore landscape-scale permeability. However, additional conservation effort should be made to restore plant species that have been lost from the agricultural landscape. Future research should aim to better define the suite of reptile species that may not be able to use the remnants at all. [ABSTRACT FROM AUTHOR]

Species with strong preferences for early or late successional stages after fire may be extinction prone under current fire regimes. However, the extent of specialisation to time since fire is poorly understood, and, for reptiles, succession models for predicting responses are in the development phase. In this study we tested predictions of a reptile succession model, and identified species that may be fire specialists. Reptiles were sampled in five burnt and unburnt mallee Eucalyptus woodlands, Australia. Two, 400m transects within each burn treatment were sampled using 11 pairs of pitfall-traps that were opened for five weeks over two summers. A habitat accommodation model of succession that was previously developed for mallee reptiles correctly predicted the observed responses of three of 16 common reptile species. A further four species showed non-significant trends in the predicted direction. However, eight other species showed unexpected responses. One species showed a strong interaction between burn age and location, requiring a two-dimensional successional model in contrast with the usual linear models explaining reptile responses to fire. One third of common species were not affected by fire and so may not have increased risks of extinction due to the fire suppression/incineration cycle. However, approximately half to two-thirds of common reptiles did have a fire response, so the risk of deterministic extinction in small fragments may be substantial. Further model development is needed to better predict fire responses and to assist the design of fire mosaics that can accommodate early and late successional fire specialists. [Copyright &y& Elsevier]