High-resolution climate data reveal an increasing risk of warming-driven activity restriction for diurnal and nocturnal lizards.

Widespread species experience a variety of climates across their distribution, which can structure their thermal tolerance, and ultimately, responses to climate change. For ectotherms, activity is highly dependent on temperature, its variability and availability of favourable microclimates. Thermal exposure and tolerance may be structured by the availability and heterogeneity of microclimates for species living along temperature and/or precipitation gradients - but patterns and mechanisms underlying such gradients are poorly understood. We measured critical thermal limits (CTmax and CTmin) for five populations of two sympatric lizard species, a nocturnal gecko (Chondrodactylus bibronii) and a diurnal skink (Trachylepis variegata) and recorded hourly thermal variation for a year in three types of microclimate relevant to the activity of lizards (crevice, full sun and partial shade) for six sites across a precipitation gradient. Using a combination of physiological and modelling approaches, we derived warming tolerance for the present and the end of the century. In the present climate, we found an overall wider thermal tolerance for the nocturnal species relative to the diurnal species, and no variation in CTmax but variable CTmin along the precipitation gradient for both species. However, warming tolerances varied significantly over the course of the day, across months and microhabitats. The diurnal skink was most restricted in its daily activity in the three driest sites with up to six daily hours of restricted activity in the open (i.e. outside refugia) during the summer months, while the impacts for the nocturnal gecko were less severe, due to its higher CTmax and night activity. With climate change, lizards will experience more months where activity is restricted and increased exposure to high temperatures even within the more sheltered microhabitats. Together our results highlight the importance of considering the relevant spatiotemporal scale and habitat for understanding the thermal exposure of diurnal and nocturnal species.

Genomic analyses reveal poaching hotspots and illegal trade in pangolins from Africa to Asia.

The white-bellied pangolin (Phataginus tricuspis) is the world's most trafficked mammal and is at risk of extinction. Reducing the illegal wildlife trade requires an understanding of its origins. Using a genomic approach for tracing confiscations and analyzing 111 samples collected from known geographic localities in Africa and 643 seized scales from Asia between 2012 and 2018, we found that poaching pressures shifted over time from West to Central Africa. Recently, Cameroon's southern border has emerged as a site of intense poaching. Using data from seizures representing nearly 1 million African pangolins, we identified Nigeria as one important hub for trafficking, where scales are amassed and transshipped to markets in Asia. This origin-to-destination approach offers new opportunities to disrupt the illegal wildlife trade and to guide anti-trafficking measures.

Strong habitat-specific phenotypic plasticity but no genome-wide differentiation across a rainforest gradient in an African butterfly.

Habitat-specific thermal responses are well documented in various organisms and likely determine the vulnerability of populations to climate change. However, the underlying roles of genetics and plasticity that shape such habitat-specific patterns are rarely investigated together. Here we examined the thermal plasticity of the butterfly Bicyclus dorothea originating from rainforest and ecotone habitats in Cameroon under common garden conditions. We also sampled wild-caught butterflies from forest and ecotone sites and used RADseq to explore genome-wide population differentiation. We found differences in the level of phenotypic plasticity across habitats. Specifically, ecotone populations exhibited greater sensitivity in wing eyespot features with variable development temperatures relative to rainforest populations. Known adaptive roles of wing eyespots in Bicyclus species suggest that this morphological plasticity is likely under divergent selection across environmental gradients. However, we found no distinct population structure of genome-wide variation between habitats, suggesting high level of ongoing gene flow between habitats is homogenizing most parts of the genome.

Ecological patterns and processes in the vertical dimension of terrestrial ecosystems.

Climatic gradients such as latitude and elevation are considered primary drivers of global biogeography. Yet, alongside these macro-gradients, the vertical space and structure generated by terrestrial plants form comparable climatic gradients but at a fraction of the distance. These vertical gradients provide a spectrum of ecological space for species to occur and coexist, increasing biodiversity. Furthermore, vertical gradients can serve as pathways for evolutionary adaptation of species traits, leading to a range of ecological specialisations. In this review, we explore the ecological evidence supporting the proposition that the vertical gradient serves as an engine driving the ecology and evolution of species and shaping larger biogeographical patterns in space and time akin to elevation and latitude. Focusing on vertebrate and invertebrate taxa, we synthesised how ecological patterns within the vertical dimension shape species composition, distribution and biotic interactions. We identify three key ecological mechanisms associated with species traits that facilitate persistence within the vertical environment and draw on empirical examples from the literature to explore these processes. Looking forward, we propose that the vertical dimension provides an excellent study template to explore timely ecological and evolutionary questions. We encourage future research to also consider how the vertical dimension will influence the resilience and response of animal taxa to global change.

Does plant ecosystem thermoregulation occur? An extratropical assessment at different spatial and temporal scales.

To what degree plant ecosystems thermoregulate their canopy temperature (Tc ) is critical to assess ecosystems' metabolisms and resilience with climate change, but remains controversial, with opinions from no to moderate thermoregulation capability. With global datasets of Tc , air temperature (Ta ), and other environmental and biotic variables from FLUXNET and satellites, we tested the 'limited homeothermy' hypothesis (indicated by Tc & Ta regression slope < 1 or Tc < Ta around midday) across global extratropics, including temporal and spatial dimensions. Across daily to weekly and monthly timescales, over 80% of sites/ecosystems have slopes ≥1 or Tc > Ta around midday, rejecting the above hypothesis. For those sites unsupporting the hypothesis, their Tc -Ta difference (ΔT) exhibits considerable seasonality that shows negative, partial correlations with leaf area index, implying a certain degree of thermoregulation capability. Spatially, site-mean ΔT exhibits larger variations than the slope indicator, suggesting ΔT is a more sensitive indicator for detecting thermoregulatory differences across biomes. Furthermore, this large spatial-wide ΔT variation (0-6°C) is primarily explained by environmental variables (38%) and secondarily by biotic factors (15%). These results demonstrate diverse thermoregulation patterns across global extratropics, with most ecosystems negating the 'limited homeothermy' hypothesis, but their thermoregulation still occurs, implying that slope < 1 or Tc < Ta are not necessary conditions for plant thermoregulation.

Familiarity with, perceptions of and attitudes toward butterflies of urban park users in megacities across East and Southeast Asia.

Perceptions of, and attitudes toward, wildlife are influenced by exposure to, and direct experiences with, nature. Butterflies are a conspicuous and ubiquitous component of urban nature across megacities that are highly urbanized with little opportunity for human-nature interactions. We evaluated public familiarity with, perceptions of and attitudes toward butterflies across nine megacities in East and Southeast Asia through face-to-face interviews with 1774 urban park users. A total of 79% of respondents had seen butterflies in their cities mostly in urban parks, indicating widespread familiarity with butterflies. Those who had seen butterflies also had higher perceptions of butterflies, whereas greater than 50% of respondents had positive attitudes toward butterflies. Frequent visits to natural places in urban neighbourhoods was associated with (i) sightings of caterpillars, indicating increased familiarity with urban wildlife, and (ii) increased connectedness to nature. We found two significant positive relationships: (i) between connectedness to nature and attitudes toward butterflies and (ii) between connectedness to nature and perceptions of butterflies, firmly linking parks users' thoughts and feelings about butterflies with their view of nature. This suggests that butterflies in urban parks can play a key role in building connectedness to nature and consequently pro-environmental behaviours and support for wildlife conservation among urban residents.

Home and hub: pet trade and traditional medicine impact reptile populations in source locations and destinations.

The pet trade and Traditional Chinese Medicine (TCM) consumption are major drivers of global biodiversity loss. Tokay geckos (Gekko gecko) are among the most traded reptile species worldwide. In Hong Kong, pet and TCM markets sell tokay geckos while wild populations also persist. To clarify connections between trade sources and destinations, we compared genetics and stable isotopes of wild tokays in local and non-local populations to dried individuals from TCM markets across Hong Kong. We found that TCM tokays are likely not of local origin. Most wild tokays were related to individuals in South China, indicating a probable natural origin. However, two populations contained individuals more similar to distant populations, indicating pet trade origins. Our results highlight the complexity of wildlife trade impacts within trade hubs. Such trade dynamics complicate local legal regulation when endangered species are protected, but the same species might also be non-native and possibly damaging to the environment.

Consistent heat tolerance under starvation across seasonal morphs in Mycalesis mineus (Lepidoptera: Nymphalidae).

Heat tolerance is a key trait for understanding insect responses to extreme heat events, but tolerance may be modulated by changes in food availability and seasonal variability in temperature. Differences in sensitivity and resistance across life stages are also important determinants of species responses. Using a full-factorial experimental design, we here investigated the effects of larval starvation, adult starvation, and seasonal morph (developmental temperature) on heat tolerance of a seasonally polyphenic butterfly, Mycalesis mineus, in both larval and adult stages. While starvation and rearing temperature profoundly influenced various life history traits in the insect, none of the treatments affected adult heat tolerance. There was also no evidence of reduced heat tolerance in larvae under starvation stress, though larval thermal tolerance was higher by ~1 °C at the higher developmental temperature. The lack of a starvation effect was unexpected given the general physiological cost of heat tolerance mechanisms. This might be attributed to the ability to tolerate heat being preserved under resource-based trade-offs due to its critical role in ensuring insect survival. Invariant heat tolerance in M. mineus shows that some insects may have thermal capacity to cope with extreme heat under short-term starvation and seasonality disruptions, though more prolonged changes may have greater consequences. The capacity to maintain key physiological function under multiple stressors will be crucial for species resilience in future novel environments.

No consistent effect of daytime versus night-time measurement of thermal tolerance in nocturnal and diurnal lizards.

While essential in understanding impacts of climate change for organisms, diel variation remains an understudied component of temporal variation in thermal tolerance limits [i.e. the critical thermal minimum (CTmin) and maximum (CTmax)]. For example, a higher Ctmax might be expected for an individual if the measurement is taken during the day (when heat stress is most likely to occur) instead of at night. We measured thermal tolerance (Ctmin and Ctmax) during both the daytime and night-time in 101 nocturnal and diurnal geckos and skinks in Hong Kong and in South Africa, representing six species and covering a range of habitats. We found that period of measurement (day vs. night) only affected Ctmin in South Africa (but not in Hong Kong) and that Ctmax was unaffected. Body size and species were important factors for determining Ctmax in Hong Kong and Ctmin in South Africa, respectively. Overall, however, we did not find consistent diel variation of thermal tolerance and suggest that measurements of critical thermal limits may be influenced by timing of measurement-but that such effects, when present, are likely to be context-dependent.

Low pangolin consumption in Hong Kong pre- and post- the COVID-19 outbreak: Conservation and health concerns both contribute to people's attitudes.

Pangolins have recently received significant media attention globally as the trade for their scales and meat is driving many species closer to extinction. As a result of this, there have been increased legal regulations placed on pangolin trade in recent years. The suggestion that pangolins may have been involved in the transmission of COVID-19 further brought the issues of pangolin consumption to the fore in 2020. However, we have little understanding of the attitudes of the general public towards pangolin consumption pre- or post the outbreak of COVID-19. We conducted surveys in Hong Kong, a critical transit hub in the trafficking routes for pangolins, in 2015 (n = 1037) and 2020 (n = 1028) to determine general attitudes towards pangolin consumption in the city, and whether these attitudes changed since the onset of COVID-19. We found low reported rates of pangolin consumption (< 1% of respondents) in both surveys, and most of the respondents who professed to eating pangolins were aged above 50. Perceptions of how trends in pangolin consumption are changing were consistent between 2015 and 2020, with 55% of the public in 2015 and 57% in 2020 believing that consumption has declined over time. In 2020, respondents cited conservation (endangered status of pangolins) and health concerns (risk of disease transmission) as the two primary reasons (> 50%) for declining attitudes toward consumption. Overall, COVID-19 does not, specifically, appear to be associated with changed perceptions of pangolin consumption in Hong Kong: > 75% of respondents stated that there is no relationship between pangolins and COVID-19, or were unsure about any such connection. Only 1% mentioned an awareness of the illegality of pangolin consumption as a reason for not consuming them. As such, our results challenge simple narratives regarding the impact of COVID-19 on pangolin consumption. We suggest that future demand reduction efforts could emphasize the conservation impact and health risks of consuming pangolins, and specifically focus on the older generations. As pangolins continue to be trafficked and threatened with extinction, further research into the perceptions and attitudes of consumers of these products is needed to inform targeted and effective interventions.

Snakebite Management and One Health in Asia Using an Integrated Historical, Social, And Ecological Framework.

Snakebite envenomation continues to contribute to high fatality and morbidity rates across Asia. Yet snake bite is one of many outcomes due to human-snake conflicts, which themselves are only one type of human-snake relationship among the diversity of such interactions. We propose that human-snake relationships need to be explored from a perspective integrative of history, ecology, and culture in order to adequately and holistically address snake bite. In order to contextualize this concept within a language already understood in conservation research, we characterize and develop four interconnected themes defining human-snake relationships as a social ecological system. By breaking down the multifaceted nature of human-snake relationships under a social ecological systems framework, we explore its applicability in contributing to a unified strategy, drawing from both social and natural sciences for ending the snakebite crisis.

Morphological and behavioural differences facilitate tropical butterfly persistence in variable environments.

The thermal biology of ectotherms largely determines their abundance and distributions. In general, tropical species inhabiting warm and stable thermal environments tend to have low tolerance to cold and variable environments, which may restrict their expansion into temperate climates. However, the distribution of some tropical species does extend into cooler areas such as tropical borders and high elevation tropical mountains. Behavioural and morphological differences may therefore play important roles in facilitating tropical species to cope with cold and variable climates at tropical edges. We used field-validated biophysical models to estimate body temperatures of butterflies across elevational gradients at three sites in southern China and assessed the contribution of behavioural and morphological differences in facilitating their persistence in tropical and temperate climates. We investigated the effects of temperature on the activity of 4,844 individuals of 144 butterfly species along thermal gradients and tested whether species of different climatic affinities-tropical and widespread (distributed in both temperate and tropical regions)-differed in their thermoregulatory strategies (i.e. basking). In addition, we tested whether thermally related morphology or the strength of solar radiation (when butterflies were recorded) was related to such differences. We found that activities of tropical species were restricted (low abundance) at low air temperatures compared to widespread species. Active tropical species were also more likely to bask at cooler body temperatures than widespread species. Heat gain from behavioural thermoregulation was higher for tropical species (when accounting for species abundance), and heat gain correlated with larger thorax widths but not with measured solar radiation. Our results indicate that physiological intolerance to cold temperatures in tropical species may be compensated through behavioural and morphological responses in thermoregulation in variable subtropical environments. Increasing climatic variability with climate change may render tropical species more vulnerable to cold weather extremes compared to widespread species that are more physiologically suited to variable environments.

Local adaptation in thermal tolerance for a tropical butterfly across ecotone and rainforest habitats.

Thermal adaptation to habitat variability can determine species vulnerability to environmental change. For example, physiological tolerance to naturally low thermal variation in tropical forests species may alter their vulnerability to climate change impacts, compared with open habitat species. However, the extent to which habitat-specific differences in tolerance derive from within-generation versus across-generation ecological or evolutionary processes are not well characterized. Here we studied thermal tolerance limits of a Central African butterfly (Bicyclus dorothea) across two habitats in Cameroon: a thermally stable tropical forest and the more variable ecotone between rainforest and savanna. Second generation individuals originating from the ecotone, reared under conditions common to both populations, exhibited higher upper thermal limits (CTmax) than individuals originating from forest (∼3°C greater). Lower thermal limits (CTmin) were also slightly lower for the ecotone populations (∼1°C). Our results are suggestive of local adaptation driving habitat-specific differences in thermal tolerance (especially CTmax) that hold across generations. Such habitat-specific thermal limits may be widespread for tropical ectotherms and could affect species vulnerability to environmental change. However, microclimate and within-generation developmental processes (e.g. plasticity) will mediate these differences, and determining the fitness consequences of thermal variation for ecotone and rainforest species will require continued study of both within-generation and across-generation eco-evolutionary processes. This article has an associated First Person interview with the first author of the paper.

A tool for rapid assessment of wildlife markets in the Asia-Pacific Region for risk of future zoonotic disease outbreaks.

Decades of warnings that the trade and consumption of wildlife could result in serious zoonotic pandemics have gone largely unheeded. Now the world is ravaged by COVID-19, with tremendous loss of life, economic and societal disruption, and dire predictions of more destructive and frequent pandemics. There are now calls to tightly regulate and even enact complete wildlife trade bans, while others call for more nuanced approaches since many rural communities rely on wildlife for sustenance. Given pressures from political and societal drivers and resource limitations to enforcing bans, increased regulation is a more likely outcome rather than broad bans. But imposition of tight regulations will require monitoring and assessing trade situations for zoonotic risks. We present a tool for relevant stakeholders, including government authorities in the public health and wildlife sectors, to assess wildlife trade situations for risks of potentially serious zoonoses in order to inform policies to tightly regulate and control the trade, much of which is illegal in most countries. The tool is based on available knowledge of different wildlife taxa traded in the Asia-Pacific Region and known to carry highly virulent and transmissible viruses combined with relative risks associated with different broad categories of market types and trade chains.

Behavior-partitioned diversity reveals differential habitat values of gardens to butterfly communities.

Diversity metrics, essential for habitat evaluation in conservation, are often based on occurrences records with little consideration of behavioral ecology. As species use diverse habitats to perform different behaviors, reliance on occurrence records alone will fail to reveal environmental conditions shaping the behavioral importance of habitats with respect to resource exploitation. Here, we integrated occurrence and behavioral records to quantify diversity and assessed how environmental determinants shape the behavioral importance of gardens to butterflies across Hong Kong. We conducted standardized butterfly sampling and behavioral observation, and recorded environmental variables related to climate, habitat quality, and landscape connectivity. We found differential responses of diversity and behavioral diversity metrics to environmental variables. Connectivity increased taxonomic richness based on occurrence and flying across records, while temperature reduced richness based on occurrence, settling and interaction records. Floral abundance increased richness based on nectaring records only. No environmental variable promoted the average number of behavioral types observed in each taxon. Our results suggest that connectivity and temperature determine the richness of butterflies reaching gardens, while floral abundance determines whether butterflies use the sites as nectaring grounds via modifying species behaviors. Our study demonstrates the utility in integrating behavioral and diversity data to reveal how environmental conditions shape behavioral importance of habitats.

Predator presence and recent climatic warming raise body temperatures of island lizards.

In ectothermic predator-prey relationships, evasion of predation by prey depends on physiological and behavioural responses relating to the thermal biology of both predator and prey. On Japan's Izu Islands, we investigated a prey lizard's physiological and thermal responses to the presence of a snake predator over geologic time in addition to recent climatic warming. Foraging lizard body temperatures increased by 1.3 °C from 1981 to 2019 overall, yet were 2.9 °C warmer on snake islands relative to snake-free islands. We also detected snake predator-induced selection on hind leg length, which in turn is a major determinant for sprint speed only in lizard populations exposed to predation by snakes. Accordingly, we found that warmer prey body temperatures result in faster sprint speeds by the prey at temperatures suboptimal for the snake predator, and therefore contribute to escaping predation. Given recent climatic change, further warming could irrevocably alter this and other ectothermic predator-prey relationships.

Author Correction: Land-use change interacts with climate to determine elevational species redistribution.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Climate Change and Thermoregulatory Consequences of Activity Time in Mammals.

Activity times structure the thermal environments experienced by organisms. In mammals, species shift from being nocturnal to diurnal and vice versa, but the thermal consequences of variable activity patterns remain largely unexplored. Here we used theoretical thermoregulatory polygons bounded by estimates of basal metabolic rates (BMR), maximum metabolic rates (MMR), and thermal conductance (C) in small mammals to explore the metabolic consequences of exposure to global-scale daytime and nighttime temperatures. Model predictions indicated higher metabolic scope for activity for nocturnal species at low latitudes and that reduced minimum C and larger body size increased the geographic range in which nocturnality was advantageous. Consistent with predictions, within rodents nocturnal species have low C. However, nocturnal mammals tend to be smaller than diurnal species, likely reflecting the importance of additional factors driving body size. Projections of warming impacts on small mammals suggest that diurnal species could lose habitable space globally. Conversely, warming could lift cool temperature constraints on nocturnal species and increase habitable space, suggesting that a shift toward nocturnal niches might be favored in a warming world. Taken together, these findings demonstrate the importance of energetic considerations for endotherms in managing global change impacts on nocturnal and diurnal species.

Omnivorous ants are less carnivorous and more protein-limited in exotic plantations.

Diets of species are crucial in determining how they influence food webs and community structures, and how their populations are regulated by different bottom-up processes. Omnivores are able to adjust their diet flexibly according to environmental conditions, such that their impacts on food webs and communities, and the macronutrients constraining their population, can be plastic. In particular, omnivore diets are known to be influenced by prey availability, which exhibits high spatial and temporal variation. To examine the plasticity of diet and macronutrient limitation in omnivores, we compared trophic positions, macronutrient preferences and food exploitation rates of omnivorous ants in invertebrate-rich (secondary forests) and invertebrate-poor (Lophostemon confertus plantations) habitats. We hypothesized that omnivorous ants would have lower trophic positions, enhanced protein limitation and reduced food exploitation rates in L. confertus plantations relative to secondary forests. We performed cafeteria experiments to examine changes in macronutrient limitation and food exploitation rates. We also sampled ants and conducted stable isotope analyses to investigate dietary shifts between these habitats. We found that conspecific ants were less carnivorous and had higher preferences for protein-rich food in L. confertus plantations compared to secondary forests. However, ant assemblages did not exhibit increased preferences for protein-rich food in L. confertus plantations. At the species-level, food exploitation rates varied idiosyncratically between habitats. At the assemblage-level, food exploitation rates were reduced in L. confertus plantations. Our results reveal that plantation establishments alter the diet and foraging behaviour of omnivorous ants. Such changes suggest that omnivorous ants in plantations will have reduced top-down impacts on prey communities but also see an increased importance of protein as a bottom-up force in constraining omnivore population sizes.