Anticipating how species distributions will shift with climate change is key for biodiversity conservation and management. Commonly, species' range shifts are observed by analyzing changes in occurrence or abundance data through time, or predicted across different climate change scenarios by modeling species' climatic niches. However, it remains unclear how well these climate-based forecasts align with empirically documented range shifts from monitoring efforts. Here, we tested the congruence between modeled range shifts, predicted using climatic niche models, and documented range shifts, derived from empirical observations collected over recent decades, for more than 9,500 range shifts across over 3,500 marine and terrestrial species. We found that documented and modeled range shifts tend to align in latitudinal direction, with greater alignment for marine (76%) than terrestrial (56%) cases. However, even when the directions aligned, documented shifts exceeded modeled shifts in 62% of cases, nearly twice as often as they lagged behind (38%), and their median rates were four times faster than those of the modeled shifts. Our findings suggest that climate-based models can approximate observed range dynamics under specific conditions, particularly over long time periods and restricted spatial areas, when habitats remain well connected and under low climate fluctuations over time. These insights provide valuable guidance for both improving predictions and informing responses to climate-driven biodiversity redistribution.

Thermophilization of communities, or shifts in composition favoring more warm-adapted species, over time and space is a common response to warming from global climate change and localized effects of land-use change. However, the interplay between community thermophilization driven by temporal warming in global climate and spatial warming in local climate is not well explored empirically. Here, we use long-term ecological monitoring of ground-dwelling arthropod communities over twenty years, sited in desert and urbanized habitats, to address the joint effects of spatiotemporal warming on community thermophilization. We found spatial convergence of high community thermophily among warm desert and highly urbanized sites, implicating temperature as a major driver of community composition. However, we found unexpected temporal declines in community thermophily, the magnitude of which depended upon space. Declines were found in urbanized sites, but not desert sites. There was evidence of both increases in occurrence of heat-intolerant taxa and decreases in heat-tolerant taxa from urban sites. Our study demonstrates the contingency of responses to recent climate change based on contemporary land-use change.

Climate-driven changes in floral resource quantity, timing, and nutritional quality can modulate access to essential nutrients for bees, with consequences for development, reproduction, physiology, and sensitivity to other stressors. Although most nutritionally focused research has centred on managed social bees, most bee species are solitary or non-eusocial and therefore experience nutritional landscapes in fundamentally different ways. Here, we examine how sociality and life-history strategy shape sensitivity to nutritional stress under climate change, and how climate-driven nutritional change could alter the costs and benefits of social behaviours. We argue that social organisation, nesting strategy, diet breadth, foraging range, body size, and colony demography shape exposure to nutritional stress, the capacity to respond to nutritional stress, and its interactions with other stressors. Integrating nutritional ecology with life-history theory will therefore be essential for improving predictions of bee vulnerability and designing conservation strategies that support a broad range of bee taxa.

Assessing heat failure across different test temperatures allows for the estimation of heat tolerance and thermal sensitivity under the thermal death time (TDT) model of damage accumulation. One challenge is phenotyping sufficient numbers of individuals. Previous work used human observations or cameras. Infrared (IR) monitors provide an alternative method. While IR monitors have been successfully used to assess heat failure, they have not been used to estimate TDT parameters. Here, we use Drosophila tripunctata to estimate heat tolerance and thermal sensitivity for males and females across 4-6 test temperatures and 6 isofemale lines, validating the use of IR monitors.

Although climatic variability has been proposed to shape physiological tolerances, and in turn, species distributions, relatively few studies have done so with measured, rather than inferred, tolerances. Here, we use recent syntheses of butterfly distributions and thermal physiological traits to evaluate this hypothesis. Our results support the hypothesis that climatic variation in temperature (annual temperature range and temperature seasonality) shapes thermal tolerance breadth, mostly through low temperature tolerance, rather than high temperature tolerance. In turn, greater tolerance breadth was associated with greater latitudinal range. Together, these results provide support for the Rapoport effect in butterflies and the climatic variability hypothesis as a key mechanism underlying this pattern. Because our study suggests that butterflies are highly sensitive to low temperature variation, contemporary distributional changes in butterflies, especially at leading range edges, are likely to continue in the future amidst rising global temperatures.

Whether the limits of species' ranges and their seasonal activity reflect physiological tolerance of climatic extremes is a long-standing question in ecology and has implications for species' responses to recent climate change. We explored these associations in butterflies, using thermal tolerance traits and traits describing geographic distribution across 119 butterfly species, as well as adult flight season phenological traits across 87 species, accompanied by nearly 30 years of temporal population abundance trends. Butterflies with more poleward cold range edges and those that emerged earlier in the season were better able to tolerate low temperatures. By contrast, heat tolerance was unrelated to the equatorward warm range edge position and the timing of peak abundance across the flight season. Nevertheless, the difference between heat tolerance and high-temperature extremes (warming tolerance) revealed differences in vulnerability of butterflies across large spatial extents from the tropics to the subarctic. Warming tolerances in the tropics approached zero or were in deficit for many species, whereas warming tolerances at higher latitudes were consistently large. Yet, even among butterflies at higher latitudes, there was substantial interspecific variation in warming tolerance. This variation in warming tolerance, including its components and correlates, had complex relationships with multi-decadal population abundance trends. In some cases, our results directly implicated climate as a factor associated with population trends, as range-wide coldadapted species had larger declines than more warm-adapted species. In other cases, our results implicated indirect effects of ecological and demographic consequences of climate adaptation to seasonal variation in temperature, as species with earlier emergence and longer flight seasons (traits associated with better cold tolerance and worse heat tolerance) had smaller population declines than species with later emergence and shorter flight seasons. These results suggest caution when using physiological trait-based analyses to forecast vulnerability without an explicit consideration of mechanism.

Because temperature has profound effects on most aspects of an organism's biology, it is clear that climatic changes will disrupt associations between organisms and their environment. These disruptions increase the risks of population decline and extirpation in the absence of compensatory responses. Although these processes have been explored in the context of global climate change, other sources of change can threaten populations. Cityscapes generally increase environmental temperature through the retention of heat from impervious surfaces, that is, the urban heat island effect. There are now many studies documenting trait responses to urban heat islands through both plastic and evolutionary mechanisms. Similarly, many other studies have linked urban heat islands to changes in insect community structure within the city footprint. Progress in these research areas has relied heavily on theory and empirical foundations from thermal biology. However, despite a burgeoning literature of temperature effects on fundamental processes that generate (epi)genetic variation and eco-evolutionary dynamics and feedbacks across levels of biological organization from genes to ecosystems, there are large knowledge gaps in how urban warming affects these processes. Here, we summarize the current state of knowledge on the effects of urban heat islands on responses at the level of organismal traits and community structure. We then explore recent advances in temperature effects on genetic and epigenetic sources of variation and eco-evolutionary dynamics to highlight the potential for using cities as venues to understand the role of contemporary warming in each process.

Cities, through the generation of urban heat islands, provide a venue for exploring contemporary convergent evolution to climatic warming. We quantified how repeatable the evolution of heat tolerance, cold tolerance, and body size was among diverse lineages in response to urban heat islands. Our study revealed significant shifts toward higher heat tolerance and diminished cold tolerance among urban populations. We further found that the magnitude of trait divergence was significantly and positively associated with the magnitude of the urban heat island, suggesting that temperature played a major role in the observed divergence in thermal tolerance. Despite these trends, the magnitude of trait responses lagged behind environmental warming. Heat tolerance responses exhibited a deficit of 0.84°C for every 1°C increase in warming, suggesting limits on adaptive evolution and consequent adaptational lags. Other moderators were predictive of greater divergence in heat tolerance, including lower baseline tolerance and greater divergence in body size. Although terrestrial species did not exhibit systematic shifts toward larger or smaller body size, aquatic species exhibited significant shifts toward smaller body size in urban habitats. Our study demonstrates how cities can be used to address long-standing questions in evolutionary biology regarding the repeatability of evolution. Importantly, this work also shows how cities can be used as forecasting tools by quantifying adaptational lags and by developing trait-based associations with responses to contemporary warming.

Shifts in species distributions are a common ecological response to climate change, and global temperature rise is often hypothesized as the primary driver. However, the directions and rates of distribution shifts are highly variable across species, systems, and studies, complicating efforts to manage and anticipate biodiversity responses to anthropogenic change. In this Review, we summarize approaches to documenting species range shifts, discuss why observed range shifts often do not match our expectations, and explore the impacts of species range shifts on nature and society. The majority (59%) of documented range shifts are directionally consistent with climate change, based on the BioShifts database of range shift observations. However, many observed species have not shifted or have shifted in directions opposite to temperature-based expectations. These lagging or expectation-contrary shifts might be explained by additional biotic or abiotic factors driving range shifts, including additional non-temperature climatic drivers, habitat characteristics, and species interactions, which are not normally considered in range shift documentations. Understanding and managing range shifts will require increasing and connecting observational biological data, generalizing range shift patterns across systems, and predicting shifts at management-relevant timescales. Warming temperatures driven by climate change are causing species geographic ranges to shift, but factors such as habitat characteristics and species interactions impact these changes. This Review examines range shift documentation, how shifts differ from temperature-based expectations, and the effects of range shifts on natural and human systems.

Long-read sequencing is driving rapid progress in genome assembly across all major groups of life, including species of the family Drosophilidae, a longtime model system for genetics, genomics, and evolution. We previously developed a cost-effective hybrid Oxford Nanopore (ONT) long-read and Illumina short-read sequencing approach and used it to assemble 101 drosophilid genomes from laboratory cultures, greatly increasing the number of genome assemblies for this taxonomic group. The next major challenge is to address the laboratory culture bias in taxon sampling by sequencing genomes of species that cannot easily be reared in the lab. Here, we build upon our previous methods to perform amplification-free ONT sequencing of single wild flies obtained either directly from the field or from ethanol-preserved specimens in museum collections, greatly improving the representation of lesser studied drosophilid taxa in whole-genome data. Using Illumina Novaseq X Plus and ONT P2 sequencers with R10.4.1 chemistry, we set a new benchmark for inexpensive hybrid genome assembly at US $150 per genome while assembling genomes from as little as 35 ng of genomic DNA from a single fly. We present 183 new genome assemblies for 179 species as a resource for drosophilid systematics, phylogenetics, and comparative genomics. Of these genomes, 62 are from pooled lab strains and 121 from single adult flies. Despite the sample limitations of working with small insects, most single-fly diploid assemblies are comparable in contiguity (>1Mb contig N50), completeness (>98% complete dipteran BUSCOs), and accuracy (>QV40 genome-wide with ONT R10.4.1) to assemblies from inbred lines. We present a well-resolved multi-locus phylogeny for 360 drosophilid and 4 outgroup species encompassing all publicly available (as of August 2023) genomes for this group. Finally, we present a Progressive Cactus whole-genome, reference-free alignment built from a subset of 298 suitably high-quality drosophilid genomes. The new assemblies and alignment, along with updated laboratory protocols and computational pipelines, are released as an open resource and as a tool for studying evolution at the scale of an entire insect family.

Ecological and evolutionary theories have proposed that species traits should be important in mediating species responses to contemporary climate change; yet, empirical evidence has so far provided mixed evidence for the role of behavioral, life history, or ecological characteristics in facilitating or hindering species range shifts. As such, the utility of trait-based approaches to predict species redistribution under climate change has been called into question. We develop the perspective, supported by evidence, that trait variation, if used carefully can have high potential utility, but that past analyses have in many cases failed to identify an explanatory value for traits by not fully embracing the complexity of species range shifts. First, we discuss the relevant theory linking species traits to range shift processes at the leading (expansion) and trailing (contraction) edges of species distributions and highlight the need to clarify the mechanistic basis of trait-based approaches. Second, we provide a brief overview of range shift-trait studies and identify new opportunities for trait integration that consider range-specific processes and intraspecific variability. Third, we explore the circumstances under which environmental and biotic context dependencies are likely to affect our ability to identify the contribution of species traits to range shift processes. Finally, we propose that revealing the role of traits in shaping species redistribution may likely require accounting for methodological variation arising from the range shift estimation process as well as addressing existing functional, geographical, and phylogenetic biases. We provide a series of considerations for more effectively integrating traits as well as extrinsic and methodological factors into species redistribution research. Together, these analytical approaches promise stronger mechanistic and predictive understanding that can help society mitigate and adapt to the effects of climate change on biodiversity. In this opinion piece, we explore under which circumstances species traits are expected to explain the rates and directions of species redistributions in response to climate change and discuss how future trait-based approaches may benefit from fully embracing the complexity of species range shifts. We provide a set of considerations that we hope will help identify the underlying drivers of species range shifts and develop effective strategies that support biodiversity conservation under climate change.image

Climate change and urbanization are two of the most prominent global drivers of biodiversity and ecosystem change. Fully understanding, predicting and mitigating the biological impacts of climate change and urbanization are not possible in isolation, especially given their growing importance in shaping human society. Here we develop an integrated framework for understanding and predicting the joint effects of climate change and urbanization on ecology, evolution and their eco-evolutionary interactions. We review five examples of interactions and then present five hypotheses that offer opportunities for predicting biodiversity and its interaction with human social and cultural systems under future scenarios. We also discuss research opportunities and ways to design resilient landscapes that address both biological and societal concerns. In this Perspective, the authors develop an integrated framework to understand and predict the joint impacts of climate change and urbanization on biodiversity and ecosystems. They review examples of interacting impacts and present opportunities for future research.

Despite the generally negative impact of urbanization on insect biodiversity, some insect species persist in urban habitats. Understanding the mechanisms underpinning the ability of insects to tolerate urban habitats is critical given the contribution of land-use change to the global insect decline. Compensatory mechanisms such as phenotypic plasticity and evolutionary change in thermal physiological traits could allow urban populations to persist under the altered thermal regimes of urban habitats. It is important to understand the contributions of plasticity and evolution to trait change along urbanization gradients as the two mechanisms operate under different constraints and timescales. Here, we examine the plastic and evolutionary responses of heat and cold tolerance (critical thermal maximum [CTmax] and critical thermal minimum [CTmin]) to warming among populations of the cabbage white butterfly, Pieris rapae, from urban and non-urban (rural) habitats using a two-temperature common garden experiment. Although we expected populations experiencing urban warming to exhibit greater CTmax and diminished CTmin through plastic and evolutionary mechanisms, our study revealed evidence only for plasticity in the expected direction of both thermal tolerance traits. We found no evidence of evolutionary divergence in either heat or cold tolerance, despite each trait showing evolutionary potential. Our results suggest that thermal tolerance plasticity contributes to urban persistence in this system. However, as the magnitude of the plastic response was low and comparable to other insect species, other compensatory mechanisms likely further underpin this species’ success in urban habitats.

Butterflies serve as key indicators of climate change impacts such as shifts in emergence timing and shifts in geographic range and distribution. However, the development of commonly used ecological forecasts based on butterfly physiological tolerance of temperature change has lagged behind that of other taxonomic groups. Here, we provide a series of related datasets comprising butterfly thermal physiological traits to enable such forecasts. We compiled data from the literature on butterfly heat and cold tolerance (critical thermal maxima and minima) for 117 species as well as heat resistance (knockdown time) for 45 species. We also present a new dataset comprising heat and cold tolerance and thermal sensitivity of metabolic rate of 28 common North American butterfly species. We envision these data to not only provide foundations for contemporary ecological forecasts of vulnerability to recent climate change, but also to aid in our understanding of butterfly ecology and evolution over historical timescales.

Species are often expected to shift their distributions either poleward or upslope to evade warming climates and colonise new suitable climatic niches. However, from 18‐years of fixed transect monitoring data on 88 species of butterfly in the midwestern United States, we show that butterflies are shifting their centroids in all directions, except towards regions that are warming the fastest (southeast). Butterflies shifted their centroids at a mean rate of 4.87 km year−1. The rate of centroid shift was significantly associated with local climate change velocity (temperature by precipitation interaction), but not with mean climate change velocity throughout the species' ranges. Species tended to shift their centroids at a faster rate towards regions that are warming at slower velocities but increasing in precipitation velocity. Surprisingly, species' thermal niche breadth (range of climates butterflies experience throughout their distribution) and wingspan (often used as metric for dispersal capability) were not correlated with the rate at which species shifted their ranges. We observed high phylogenetic signal in the direction species shifted their centroids. However, we found no phylogenetic signal in the rate species shifted their centroids, suggesting less conserved processes determine the rate of range shift than the direction species shift their ranges. This research shows important signatures of multidirectional range shifts (latitudinal and longitudinal) and uniquely shows that local climate change velocities are more important in driving range shifts than the mean climate change velocity throughout a species' entire range.

Winter presents a challenge for survival, yet temperate ectotherms have remarkable physiological adaptations to cope with low-temperature conditions. Under recent climate change, rather than strictly relaxing pressure on overwintering survival, warmer winters can instead disrupt these low-temperature trait-environment associations, with negative consequences for populations. While there is increasing evidence of physiological adaptation to contemporary warming during the growing season, the effects of winter warming on physiological traits are less clear. To address this knowledge gap, we performed a common garden experiment using relatively warm-adapted versus cold-adapted populations of the acorn ant, Temnothorax curvispinosus, sampled across an urban heat island gradient, to explore the effects of winter conditions on plasticity and evolution of physiological traits. We found no evidence of evolutionary divergence in chill coma recovery nor in metabolic rate at either of two test temperatures (4 and 10 °C). Although we found the expected plastic response of increased metabolic rate under the 10 °C acute test temperature as compared with the 4 °C test temperature, this plastic response, (i.e., the acute thermal sensitivity of metabolic rate), was not different across populations. Surprisingly, we found that winter-acclimated urban ant populations exhibited higher heat tolerance compared with rural ant populations, and that the magnitude of divergence was comparable to that observed among growing-season acclimated ants. Finally, we found no evidence of differences between populations with respect to changes in colony size from the beginning to the end of the overwintering experiment. Together, these findings indicate that despite the evolution of higher heat tolerance that is often accompanied by losses in low-temperature tolerance, urban acorn ants have retained several components of low-temperature physiological performance when assessed under ecologically relevant overwintering conditions. Our study suggests the importance of measuring physiological traits under seasonally-relevant conditions to understand the causes and consequences of evolutionary responses to contemporary warming.

Insects exhibit divergent biodiversity responses to cities. Many urban populations are not at equilibrium: biodiversity decline or recovery from environmental perturbation is often still in progress. Substantial variation in urban biodiversity patterns suggests the need to understand its mechanistic basis. In addition, current urban infrastructure decisions might profoundly influence future biodiversity trends. Although many nature-based solutions to urban climate problems also support urban insect biodiversity, trade-offs are possible and should be avoided to maximize biodiversity-climate cobenefits. Because insects are coping with the dual threats of urbanization and climate change, there is an urgent need to design cities that facilitate persistence within the city footprint or facilitate compensatory responses to global climate change as species transit through the city footprint.

Physiological traits are often used for vulnerability assessments of organismal responses to climate change. Trait values can change dramatically over the life cycle of organisms but are typically assessed at a single developmental stage. Reconciling ontogenetic changes in physiological traits with vulnerability assessments often reveals early life-stage vulnerabilities. The degree to which ontogenetic changes in physiological traits are due to changes in body mass over development versus stage-specific responses determines the degree to which mass can be used as a proxy for vulnerability. Here, we use the painted lady butterfly, Vanessa cardui, to test ontogenetic changes in two physiological traits, the acute thermal sensitivity of routine metabolic rate (RMR Q(10)) and the critical thermal maximum (CTmax). RMR Q(10) generally followed ontogenetic changes in body mass, with stages characterized by smaller body mass exhibiting lower acute thermal sensitivity. However, CTmax was largely decoupled from ontogenetic changes in body mass. In contrast with trends from other studies showing increasing vulnerability among progressively earlier developmental stages, our study revealed highly erratic patterns of vulnerability across ontogeny. Specifically, we found the lowest joint-trait vulnerability (both RMR Q(10) and CTmax) in the earliest developmental stage we tested (3rd instar larvae), the highest vulnerabilities in the next two developmental stages (4th and 5th instar larvae), and reduced vulnerability into the pupal and adult stages. Our study supports growing evidence of mechanistic decoupling of physiology across developmental stages and suggests that body mass is not a universal proxy for all physiological trait indicators of climate vulnerability.

Decades of research have illuminated the underlying ingredients that determine the scope of evolutionary responses to climate change. The field of evolutionary biology therefore stands ready to take what it has learned about influences upon the rate of adaptive evolution-such as population demography, generation time, and standing genetic variation-and apply it to assess if and how populations can evolve fast enough to "keep pace" with climate change. Here, our review highlights what the field of evolutionary biology can contribute and what it still needs to learn to provide more mechanistic predictions of the winners and losers of climate change. We begin by developing broad predictions for contemporary evolution to climate change based on theory. We then discuss methods for assessing climate-driven contemporary evolution, including quantitative genetic studies, experimental evolution, and space-for-time substitutions. After providing this mechanism-focused overview of both the evidence for evolutionary responses to climate change and more specifically, evolving to keep pace with climate change, we next consider the factors that limit actual evolutionary responses. In this context, we consider the dual role of phenotypic plasticity in facilitating but also impeding evolutionary change. Finally, we detail how a deeper consideration of evolutionary constraints can improve forecasts of responses to climate change and therefore also inform conservation and management decisions.This article is categorized under:Climate, Ecology, and Conservation > Observed Ecological ChangesClimate, Ecology, and Conservation > Extinction RiskAssessing Impacts of Climate Change > Evaluating Future Impacts of Climate Change

The resilience of ecosystem function under global climate change is governed by individual species vulnerabilities and the functional groups they comprise. Yet it remains unclear whether the species that contribute to different functional processes which underpin ecosystem function exhibit differential vulnerability to climate change. We used existing thermal physiological trait data across a range of terrestrial species to examine the vulnerability of key functional groups to climate change (e.g. decomposers, primary producers, pollinators, primary, secondary and tertiary consumers). We found that primary producers had the broadest warming margins across the globe, and that vulnerability tended to increase with trophic level. However, we found that vulnerability within functional groups changed across geographic scales, where some groups were more vulnerable in low-latitude regions and others were more vulnerable at mid-latitude regions. This study provides a critical first step in linking individual species vulnerabilities with whole ecosystem responses to climate change.