Evolution of butterfly seasonal plasticity driven by climate change varies across life stages

Photoperiod is a common cue for seasonal plasticity and phenology, but climate change can create cue–environment mismatches for organisms that rely on it. Evolution could potentially correct these mismatches, but phenology often depends on multiple plastic decisions made during different life stages and seasons that may evolve separately. For example, Pararge aegeria (Speckled wood butterfly) has photoperiod-cued seasonal life history plasticity in two different life stages: larval development time and pupal diapause. We tested for climate change-associated evolution of this plasticity by replicating common garden experiments conducted on two Swedish populations 30 years ago. We found evidence for evolutionary change in the contemporary larval reaction norm—although these changes differed between populations—but no evidence for evolution of the pupal reaction norm. This variation in evolution across life stages demonstrates the need to consider how climate change affects the whole life cycle to understand its impacts on phenology.     

A phenological shift in the time of recruitment of the shipworm,Teredo navalis L., mirrors marine climate change

For many species, seasonal changes in key environmental variables such as food availability, light, and temperature drive the timing (“phenology”) of major life‐history events. Extensive evidence from terrestrial, freshwater, and marine habitats shows that global warming is changing the timings of many biological events; however, few of these studies have investigated the effects of climate change on the phenology of larval recruitment in marine invertebrates. Here, we studied temperature‐related phenological shifts in the breeding season of the shipworm Teredo navalis (Mollusca, Bivalvia). We compared data for the recruitment period of T. navalis along the Swedish west coast during 2004–2006 with similar data from 1971–1973, and related differences in recruitment timing to changes in sea surface temperature over the same period. We found no significant shift in the timing of onset of recruitment over this ~30‐year time span, but the end of recruitment was an average of 26 days later in recent years, leading to significantly longer recruitment periods. These changes correlated strongly with increased sea surface temperatures and coincided with published thermal tolerances for reproduction in T. navalis. Our findings are broadly comparable with other reports of phenological shifts in marine species, and suggest that warmer sea surface temperatures are increasing the likelihood of successful subannual reproduction and intensifying recruitment of T. navalis in this region.     

Strong evidence for changing fish reproductive phenology under climate warming on the Tibetan Plateau

Phenological responses to climate change have been widely observed and have profound and lasting effects on ecosystems and biodiversity. However, compared to terrestrial ecosystems, the long‐term effects of climate change on species’ phenology are poorly understood in aquatic ecosystems. Understanding the long‐term changes in fish reproductive phenology is essential for predicting population dynamics and for informing management strategies, but is currently hampered by the requirement for intensive field observations and larval identification. In this study, a very low‐frequency sampling of juveniles and adults combined with otolith measurements (long axis length of the first annulus; LAFA) of an endemic Tibetan Plateau fish (Gymnocypris selincuoensis) was used to examine changes in reproductive phenology associated with climate changes from the 1970s to 2000s. Assigning individual fish to their appropriate calendar year class was assisted by dendrochronological methods (crossdating). The results demonstrated that LAFA was significantly and positively associated with temperature and growing season length. To separate the effects of temperature and the growing season length on LAFA growth, measurements of larval otoliths from different sites were conducted and revealed that daily increment additions were the main contributor (46.3%), while temperature contributed less (12.0%). Using constructed water‐air temperature relationships and historical air temperature records, we found that the reproductive phenology of G. selincuoensis was strongly advanced in the spring during the 1970s and 1990s, while the increased growing season length in the 2000s was mainly due to a delayed onset of winter. The reproductive phenology of G. selincuoensis advanced 2.9 days per decade on average from the 1970s to 2000s, and may have effects on recruitment success and population dynamics of this species and other biota in the ecosystem via the food web. The methods used in this study are applicable for studying reproductive phenological changes across a wide range of species and ecosystems.     

Earlier Migration Timing,Decreasing Phenotypic Variation,and Biocomplexity in Multiple Salmonid Species

Climate-induced phenological shifts can influence population, evolutionary, and ecological dynamics, but our understanding of these phenomena is hampered by a lack of long-term demographic data. We use a multi-decade census of 5 salmonid species representing 14 life histories in a warming Alaskan stream to address the following key questions about climate change and phenology: How consistent are temporal patterns and drivers of phenology for similar species and alternative life histories? Are shifts in phenology associated with changes in phenotypic variation? How do phenological changes influence the availability of resource subsidies? For most salmonid species, life stages, and life histories, freshwater temperature influences migration timing – migration events are occurring earlier in time (mean = 1.7 days earlier per decade over the 3–5 decades), and the number of days over which migration events occur is decreasing (mean = 1.5 days per decade). Temporal trends in migration timing were not correlated with changes in intra-annual phenotypic variation, suggesting that these components of the phenotypic distribution have responded to environmental change independently. Despite commonalities across species and life histories, there was important biocomplexity in the form of disparate shifts in migration timing and variation in the environmental factors influencing migration timing for alternative life history strategies in the same population. Overall, adult populations have been stable during these phenotypic and environmental changes (λ ≈1.0), but the temporal availability of salmon as a resource in freshwater has decreased by nearly 30 days since 1971 due to changes in the median date of migration timing and decreases in intra-annual variation in migration timing. These novel observations advance our understanding of phenological change in response to climate warming, and indicate that climate change has influenced the ecology of salmon populations, which will have important consequences for the numerous species that depend on this resource.     

Phenological changes in intertidal con‐specific gastropods in response to climate warming

There is substantial evidence from terrestrial and freshwater systems of species responding to climate change through changes in their phenology. In the marine environment, however, there is less evidence. Using historic (1946–1949) and contemporary (2003–2007) data, collected from rocky shores of south‐west Britain, we investigated the affect of recent climate warming on the reproductive phenology of two con‐specific intertidal limpet grazers, with cool/boreal and warm/lusitanian centres of distribution. Reproductive development in the southern limpet, Patella depressa, has advanced, on average, 10.2 days per decade since the 1940s, with a longer reproductive season and more of the population reproductively active. The peak in the proportion of the population in advanced stages of gonad development was positively correlated with sea surface temperature (SST) in late spring/early summer, which has increased between the 1940s and 2000s. The advance in peak reproductive development of this species is double the average observed for terrestrial and freshwater systems and indicates, along with other studies, that marine species may be responding faster to climate warming. In contrast, the northern limpet, Patella vulgata, has experienced a delay in the timing of its reproductive development (on average 3.3 days per decade), as well as an increase in reproductive failure years and a reduction in the proportion of the population reaching advanced gonad stages. These results are the first to demonstrate a delay in the reproductive development of a cool‐temperate, winter spawner, towards cooler more favourable environmental conditions in response to climate warming. Such a delay in spawning will potentially lead to trophic miss‐matches, resulting in a rapid nonlinear decline of this species.     

Climate warming: a loss of variation in populations can accompany reproductive shifts

The most documented response of organisms to climate warming is a change in the average timing of seasonal activities (phenology). Although we know that these average changes can differ among species and populations, we do not know whether climate warming impacts within‐population variation in phenology. Using data from five study sites collected during a 13‐year survey, we found that the increase in spring temperatures is associated with a reproductive advance of 10 days in natural populations of common lizards (Zootoca vivipara). Interestingly, we show a correlated loss of variation in reproductive dates within populations. As illustrated by a model, this shortening of the reproductive period can have significant negative effects on population dynamics. Consequently, we encourage tests in other species to assess the generality of decreased variation in phenological responses to climate change.     

31种木本植物开花物候与系统发育的关系

植物物候通常被认为是由环境因素,如降水、温度和日照长度所决定,然而环境因素是否是物候唯一的决定因素仍然存在很大争议。谱系结构表征了植物在进化上的顺序,该发育时序是否对物候产生影响,当前仍然未知。在调查2016年春季新疆乌鲁木齐市最常见的31种木本植物的初始开花时间、败花时间和开花持续时间的基础上,通过分析植物开花物候的分布特征、开花物候在乔灌木间的差别、以及植物谱系距离与开花物候距离间的关系,试图揭示植物的开花物候和物种谱系(进化)顺序间的关系。结果表明:(1)新疆乌鲁木齐市31种木本植物的初始开花时间为4月18日±9d、败花时间为5月5日±12d、开花持续时间为(16±8)d;(2)乔木的初始开花时间和败花时间的标准差分别均低于灌木,乔木开花物候相对灌木更稳定;(3)乔木的初始开花和败花时间均显著早于灌木(P0.05),但开花持续时间在两者间未有显著性差异(P0.05);(3)31种木本植物间的初始开花时间距离、败花时间距离和开花持续时间距离均与物种谱系距离存在显著线性回归关系(P0.05)。综上可知:乔灌木在垂直空间上的分化使得木本植物的开花物候在植物生活型间存在不同。对植物的开花物候,除已被证明的降水、温度和日照长度等环境因素的影响外,物种进化顺序也可能造成了它在植物种间、时间和空间上的变异。     

Changes in voltinism in a pine moth <Emphasis Type="Italic">Dendrolimus spectabilis</Emphasis> (Lepidoptera: Lasiocampidae) population: implications of climate change

Climate change induces an alteration in the life cycle of many poikilothermic organisms, resulting in changes in the structure and function of communities. Changes in voltinism in the pine moth Dendrolimus spectabilis (Butler), which is known to be univoltine in South Korea, were studied to elucidate the effects of climate change on their voltinism. The developmental stages of the pine moth were evaluated through field surveys, and the developmental rate was estimated at five different temperatures: 17, 20, 25, 28, and 32°C. Field surveys showed that the moths completed two generations per year, indicating that the phenology of the pine moth in this area had changed from univoltinism to bivoltinism. Laboratory experiments showed that increasing the temperature could induce a change in voltinism in the pine moth population. Generations of the bivoltine population displayed phenotypic plasticity: the fitness of the first generation was greater than that of the second generation with regard to size and fecundity. The difference in fitness between the first and second generations could be due to the influence of factors such as low food quality and heat stress on the second generation. Therefore, changes in thermal conditions due to climate change have offered this species the chance to develop a bivoltine population, but they have also exerted ecological costs, especially for the second generation of the pine moth.     

Species-specific changes in the phenology and peak abundance of freshwater copepods in response to warm summers

SUMMARY 1. Climate warming is now widely recognised as a major factor influencing ecological processes in terrestrial, marine and freshwater habitats. Here, we investigated how a recent period of warm springs and summers has affected the population dynamics of various cyclopoid copepods in a central European lake. We compared (i) the duration of the period when the species were present in the water column, and (ii) their annual peak density in a period dominated by cool summers (1980–91) and one dominated by warm summers (1992–99). 2. The copepods under investigation were (i) Thermocyclops oithonoides, (ii) Mesocyclops leuckarti and (iii) Acanthocyclops robustus. These species differ in their thermal demand and seasonal phenology. Therefore, we hypothesised that enhanced summer warming would produce species‐specific responses. 3. The active phase of the copepods was usually prolonged both in spring and autumn. The earlier emergence of T. oithonoides (May in the warm years, July in the cool years) was probably related to high water temperature in late spring. The later onset of winter diapause in all species may have been coupled to raised temperature in late summer and autumn. 4. The annual peak abundance of the two thermophiles M. leuckarti and T. oithonoides increased significantly in the warm period. In the latter case, the increase was probably because of the early start to population growth. In contrast, M. leuckarti probably responded primarily to mid‐summer heat waves, in that its development time was likely to be short. We speculate that the increase in population size of both species resulted from the development of an additional generation (three instead of two cohorts per year). In contrast to these thermophiles, the coexisting A. robustus, which is adapted to a broader temperature range, did not respond noticeably to the warming trend. 5. In general, the nature of these responses to summer warming varied substantially among species, and depended on the detailed seasonal patterning of the warming. Our findings thus support the hypotheses that single species are sensitive indicators of climate change, and that the seasonal timing of warming is crucial in the context of climate–ecosystem relationships. 6. Moreover, our results add to the body of evidence that climate warming produces shifts in the seasonal phenology of aquatic and terrestrial organisms.     

Beyond the usual climate? Factors determining flowering and fruiting phenology across a genus over 117 years

Premise

Although changes in plant phenology are largely attributed to changes in climate, the roles of other factors such as genetic constraints, competition, and self-compatibility are underexplored.

Methods

We compiled >900 herbarium records spanning 117 years for all eight nominal species of the winter-annual genus Leavenworthia (Brassicaceae). We used linear regression to determine the rate of phenological change across years and phenological sensitivity to climate. Using a variance partitioning analysis, we assessed the relative influence of climatic and nonclimatic factors (self-compatibility, range overlap, latitude, and year) on Leavenworthia reproductive phenology.

Results

Flowering advanced by ~2.0 days and fruiting by ~1.3 days per decade. For every 1°C increase in spring temperature, flowering advanced ~2.3 days and fruiting ~3.3 days. For every 100 mm decrease in spring precipitation, each advanced ~6–7 days. The best models explained 35.4% of flowering variance and 33.9% of fruiting. Spring precipitation accounted for 51.3% of explained variance in flowering date and 44.6% in fruiting. Mean spring temperature accounted for 10.6% and 19.3%, respectively. Year accounted for 16.6% of flowering variance and 5.4% of fruiting, and latitude for 2.3% and 15.1%, respectively. Nonclimatic variables combined accounted for <11% of the variance across phenophases.

Conclusions

Spring precipitation and other climate-related factors were dominant predictors of phenological variance. Our results emphasize the strong effect of precipitation on phenology, especially in the moisture-limited habitats preferred by Leavenworthia. Among the many factors that determine phenology, climate is the dominant influence, indicating that the effects of climate change on phenology are expected to increase.     

Developmental trap or demographic bonanza? Opposing consequences of earlier phenology in a changing climate for a multivoltine butterfly

A rapidly changing climate has the potential to interfere with the timing of environmental cues that ectothermic organisms rely on to initiate and regulate life history events. Short‐lived ectotherms that exhibit plasticity in their life history could increase the number of generations per year under warming climate. If many individuals successfully complete an additional generation, the population experiences an additional opportunity to grow, and a warming climate could lead to a demographic bonanza. However, these plastic responses could become maladaptive in temperate regions, where a warmer climate could trigger a developmental pathway that cannot be completed within the growing season, referred to as a developmental trap. Here we incorporated detailed demography into commonly used photothermal models to evaluate these demographic consequences of phenological shifts due to a warming climate on the formerly widespread, multivoltine butterfly (Pieris oleracea). Using species‐specific temperature‐ and photoperiod‐sensitive vital rates, we estimated the number of generations per year and population growth rate over the set of climate conditions experienced during the past 38 years. We predicted that populations in the southern portion of its range have added a fourth generation in recent years, resulting in higher annual population growth rates (demographic bonanzas). We predicted that populations in the Northeast United States have experienced developmental traps, where increases in the thermal window initially caused mortality of the final generation and reduced growth rates. These populations may recover if more growing degree days are added to the year. Our framework for incorporating detailed demography into commonly used photothermal models demonstrates the importance of using both demography and phenology to predict consequences of phenological shifts.     

Changes in autumn vegetation dormancy onset date and the climate controls across temperate ecosystems in China from 1982 to 2010

Vegetation phenology is a sensitive indicator of the dynamic response of terrestrial ecosystems to climate change. In this study, the spatiotemporal pattern of vegetation dormancy onset date (DOD) and its climate controls over temperate China were examined by analysing the satellite‐derived normalized difference vegetation index and concurrent climate data from 1982 to 2010. Results show that preseason (May through October) air temperature is the primary climatic control of the DOD spatial pattern across temperate China, whereas preseason cumulative precipitation is dominantly associated with the DOD spatial pattern in relatively cold regions. Temporally, the average DOD over China's temperate ecosystems has delayed by 0.13 days per year during the past three decades. However, the delay trends are not continuous throughout the 29‐year period. The DOD experienced the largest delay during the 1980s, but the delay trend slowed down or even reversed during the 1990s and 2000s. Our results also show that interannual variations in DOD are most significantly related with preseason mean temperature in most ecosystems, except for the desert ecosystem for which the variations in DOD are mainly regulated by preseason cumulative precipitation. Moreover, temperature also determines the spatial pattern of temperature sensitivity of DOD, which became significantly lower as temperature increased. On the other hand, the temperature sensitivity of DOD increases with increasing precipitation, especially in relatively dry areas (e.g. temperate grassland). This finding stresses the importance of hydrological control on the response of autumn phenology to changes in temperature, which must be accounted in current temperature‐driven phenological models.     

日光诱导叶绿素荧光对亚热带常绿针叶林物候的追踪

植被物候期(春季返青和秋季衰老)是表征生物响应和陆地碳循环的基础信息。由于常绿针叶林冠层绿度的季节变动较弱,遥感提取常绿针叶林的物候信息存在着较大的不确定性,是目前区域物候监测中的难点。利用MODIS植被指数(归一化植被指数NDVI和增强型植被指数EVI)、GOME-2日光诱导叶绿素荧光(SIF)和通量数据(总初级生产力GPP)估算2007—2011年亚热带常绿针叶林物候期,用来比较三类遥感指数估算常绿针叶林物候的差异。结果表明:基于表征光合作用物候的通量GPP数据估算得到5年内亚热带常绿针叶林生长季开始时间(SOS_GPP)为第63天,生长季结束时间(EOS_GPP)为第324天,生长季长度为272天;基于反映植被光合作用特征的SIF曲线获得物候信息要滞后GPP物候期,其中生长季开始时间滞后19天,生长季结束时间滞后2天;基于传统植被指数NDVI和EVI的物候期滞后GPP物候期的时间要大于SIF滞后期,其中植被指数SOS滞后SOS_GPP31天,植被指数EOS滞后EOS_GPP10—17天。虽然基于3种遥...     

Phenological delay despite warming in wood frog Rana sylvatica reproductive timing: a 20-year study

Across all taxa, amphibians exhibit some of the strongest phenological shifts in response to climate change. As climates warm, amphibians and other animals are expected to breed earlier in response to temperature cues. However, if species use fixed cues such as daylight, their breeding timing might remain fixed, potentially creating disconnects between their life history and environmental conditions. Wood frogs Rana sylvatica are a cold-adapted species that reproduce in early spring, immediately after breeding ponds are free of ice. We used long-term surveys of wood frog oviposition timing in 64 breeding ponds over 20 yr to show that, despite experiencing a warming of 0.29°C per decade in annual temperature, wood frog breeding phenology has shifted later by 2.8 d since 2000 (1.4 d per decade; 4.8 d per °C). This counterintuitive pattern is likely the result of changes in the timing of snowpack accumulation and melting. Finally, we used relationships between climate and oviposition between 2000 and 2018 to hindcast oviposition dates from climate records to model longer-term trends since 1980. Our study indicates that species can respond to fine-grained seasonal climate heterogeneity within years that is not apparent or counterintuitive when related to annual trends across years.     

Spring phenology of cotton bollworm affects wheat yield

Climate change has changed numerous species phenologies. Understanding the asynchronous responses between pest insects and host plants to climate change is helpful in improving integrated pest management. It is necessary to use long‐term data to analyze the effects of climate change on cotton bollworm and wheat anthesis. Data for cotton bollworm, wheat yield, and wheat anthesis collected since 1990 were analyzed using linear regression and partial least‐squares regression, as well as the Mann–Kendall test. The results showed that warmer temperatures in the spring advanced the phenologies of cotton bollworm and wheat anthesis, but the phenology changes in overwintering cotton bollworm were faster than those in wheat anthesis, and the eclosion period of overwintering was prolonged, resulting in an increase in overwintering adult abundance. This might lead to more first‐generation larvae and subsequent wheat damage. An early or late first‐appearance date significantly affected the eclosion days. The abrupt changes of phenologies in cotton bollworm, wheat anthesis, and climate were asynchronous, but the abrupt phenology changes occurred after or around the climate abrupt change, especially after or around the abrupt changes of temperature in March and April. The expansion of asynchronous responses in the change rate of wheat anthesis and overwintering cotton bollworm would likely decrease wheat yield due to climate warming in the future. Accumulated temperature was the major affecting factor on the first eclosion date (t₁), adult abundance, and eclosion days. Temperatures in March and April and precipitation in the winter mainly affected the prepeak date (t₂), peak date (t₃), and postpeak date (t₄), respectively, and these factors indirectly affected wheat yield. Thus, the change in the spring phenology of the cotton bollworm and wheat anthesis, and hence wheat yield, was affected by climate warming.     

Quantifying long-term phenological patterns of aerial insectivores roosting in the Great Lakes region using weather surveillance radar

Organisms have been shifting their timing of life history events (phenology) in response to changes in the emergence of resources induced by climate change. Yet understanding these patterns at large scales and across long time series is often challenging. Here we used the US weather surveillance radar network to collect data on the timing of communal swallow and martin roosts and evaluate the scale of phenological shifts and its potential association with temperature. The discrete morning departures of these aggregated aerial insectivores from ground-based roosting locations are detected by radars around sunrise. For the first time, we applied a machine learning algorithm to automatically detect and track these large-scale behaviors. We used 21 years of data from 12 weather surveillance radar stations in the Great Lakes region to quantify the phenology in roosting behavior of aerial insectivores at three spatial levels: local roost cluster, radar station, and across the Great Lakes region. We show that their peak roosting activity timing has advanced by 2.26 days per decade at the regional scale. Similar signals of advancement were found at the station scale, but not at the local roost cluster scale. Air temperature trends in the Great Lakes region during the active roosting period were predictive of later stages of roosting phenology trends (75% and 90% passage dates). Our study represents one of the longest-term broad-scale phenology examinations of avian aerial insectivore species responding to environmental change and provides a stepping stone for examining potential phenological mismatches across trophic levels at broad spatial scales.     

Phenological responses of plants to climate change in an urban environment

Global climate change is likely to alter the phenological patterns of plants due to the controlling effects of climate on plant ontogeny, especially in an urbanized environment. We studied relationships between various phenophases (i.e., seasonal biological events) and interannual variations of air temperature in three woody plant species (Prunus davidiana, Hibiscus syriacus, and Cercis chinensis) in the Beijing Metropolis, China, based on phenological data for the period 1962–2004 and meteorological data for the period 1951–2004. Analysis of phenology and climate data indicated significant changes in spring and autumn phenophases and temperatures. Changes in phenophases were observed for all the three species, consistent with patterns of rising air temperatures in the Beijing Metropolis. The changing phenology in the three plant species was reflected mainly as advances of the spring phenophases and delays in the autumn phenophases, but with strong variations among species and phenophases in response to different temperature indices. Most phenophases (both spring and autumn phenophases) had significant relationships with temperatures of the preceding months. There existed large inter- and intra-specific variations, however, in the responses of phenology to climate change. It is clear that the urban heat island effect from 1978 onwards is a dominant cause of the observed phenological changes. Differences in phenological responses to climate change may cause uncertain ecological consequences, with implications for ecosystem stability and function in urban environments.     

Incorporating variability in simulations of seasonally forced phenology using integral projection models

Phenology models are becoming increasingly important tools to accurately predict how climate change will impact the life histories of organisms. We propose a class of integral projection phenology models derived from stochastic individual‐based models of insect development and demography. Our derivation, which is based on the rate summation concept, produces integral projection models that capture the effect of phenotypic rate variability on insect phenology, but which are typically more computationally frugal than equivalent individual‐based phenology models. We demonstrate our approach using a temperature‐dependent model of the demography of the mountain pine beetle (Dendroctonus ponderosae Hopkins), an insect that kills mature pine trees. This work illustrates how a wide range of stochastic phenology models can be reformulated as integral projection models. Due to their computational efficiency, these integral projection models are suitable for deployment in large‐scale simulations, such as studies of altered pest distributions under climate change.     

西安4种落叶乔木物候期对气候变化的响应

以西安1979—2018年的气候资料和植物物候观测资料为基础,采用分段回归和趋势倾向率等方法,分析了毛白杨(Populus tomentosa)、杜梨(Pyrus betulifolia)、七叶树(Aesculus chinensis)和灯台树(Bothrocaryum controversum)4种落叶乔木展叶盛期和叶全变色期的生长趋势,使用偏相关分析探讨了气温、降水和日照时数与物候期的关系并通过偏最小二乘回归(Partial Least Squares, PLS)判断气候变量对物候期的综合影响。结果表明：(1)1979—2018年,4种乔木的生长季长度延长,整体表现为春季物候期提前,秋季物候期推迟;(2)展叶盛期物候指标与叶全变色期物候指标,转折均发生在1982年;转折后,物候特征变化显著,春季物候的提前速率和秋季物候的推迟速率加快,展叶盛期平均提前3.8d/10a,叶全变色期平均推迟4.7d/10a;(3)展叶盛期与春季气温表现为极显著负相关,叶变色期与秋季气温表现为显著正相关;降水对植物物候的影响不显著;春季物候与日照时数呈现极显著负相关关系,秋季物候期与日照时数呈不显著正相关...     

Similarities in butterfly emergence dates among populations suggest local adaptation to climate

Phenology shifts are the most widely cited examples of the biological impact of climate change, yet there are few assessments of potential effects on the fitness of individual organisms or the persistence of populations. Despite extensive evidence of climate‐driven advances in phenological events over recent decades, comparable patterns across species' geographic ranges have seldom been described. Even fewer studies have quantified concurrent spatial gradients and temporal trends between phenology and climate. Here we analyse a large data set (~129 000 phenology measures) over 37 years across the UK to provide the first phylogenetic comparative analysis of the relative roles of plasticity and local adaptation in generating spatial and temporal patterns in butterfly mean flight dates. Although populations of all species exhibit a plastic response to temperature, with adult emergence dates earlier in warmer years by an average of 6.4 days per °C, among‐population differences are significantly lower on average, at 4.3 days per °C. Emergence dates of most species are more synchronised over their geographic range than is predicted by their relationship between mean flight date and temperature over time, suggesting local adaptation. Biological traits of species only weakly explained the variation in differences between space‐temperature and time‐temperature phenological responses, suggesting that multiple mechanisms may operate to maintain local adaptation. As niche models assume constant relationships between occurrence and environmental conditions across a species' entire range, an important implication of the temperature‐mediated local adaptation detected here is that populations of insects are much more sensitive to future climate changes than current projections suggest.