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Agri-environment schemes are programmes where landholders enter into voluntary agreements (typically with\ud governments) to manage agricultural land for environmental protection and nature conservation objectives.\ud Previous work at local scale has shown that these features can provide additional floral and nesting resources to\ud support wild pollinators, which may indirectly increase floral visitation to nearby crops. However, the effect of\ud entire schemes on this important ecosystem service has never previously been studied at national scale. Focusing\ud on four wild pollinator guilds (ground-nesting bumblebees, tree-nesting bumblebees, ground-nesting solitary\ud bees, and cavity-nesting solitary bees), we used a state-of-the-art, process-based spatial model to examine the\ud relationship between participation in agri-environment schemes across England during 2016 and the predicted\ud abundances of these guilds and their visitation rates to four pollinator dependent crops (oilseed rape, field beans,\ud orchard fruit and strawberries). Our modelling predicts that significant increases in national populations of\ud ground-nesting bumblebees and ground-nesting solitary bees have occurred in response to the schemes. Lack of\ud significant population increases for other guilds likely reflects specialist nesting resource requirements not wellcatered\ud for in schemes. We do not predict statistically significant increases in visitation to pollinator-dependent\ud crops at national level as a result of scheme interventions but do predict some localised areas of significant\ud increase in bumblebee visitation to crops flowering in late spring. Lack of any significant change in visitation to\ud crops which flower outside this season is likely due to a combination of low provision of nesting resource relative\ud to floral resource by scheme interventions and low overall participation in more intensively farmed landscapes.\ud We recommend future schemes place greater importance on nesting resource provision alongside floral resource\ud provision, better cater for the needs of specialised species and promote more contiguous patches of semi-natural\ud habitat to better support solitary bee visitation.

Significance The painted lady butterfly is an annual migrant to northern regions, but the size of the immigration varies by more than 100-fold in successive years. Unlike the monarch, the painted lady breeds year round, and it has long been suspected that plant-growing conditions in winter-breeding locations drive this high annual variability. However, the regions where caterpillars develop over winter remained unclear. Here, we show for the European summer population that winter plant greenness in the savanna of sub-Saharan Africa is the key driver of the size of the spring immigration. Our results show that painted ladies regularly cross the Sahara Desert and elucidate the climatic drivers of the annual population dynamics., Many latitudinal insect migrants including agricultural pests, disease vectors, and beneficial species show huge fluctuations in the year-to-year abundance of spring immigrants reaching temperate zones. It is widely believed that this variation is driven by climatic conditions in the winter-breeding regions, but evidence is lacking. We identified the environmental drivers of the annual population dynamics of a cosmopolitan migrant butterfly (the painted lady Vanessa cardui) using a combination of long-term monitoring and climate and atmospheric data within the western part of its Afro-Palearctic migratory range. Our population models show that a combination of high winter NDVI (normalized difference vegetation index) in the Savanna/Sahel of sub-Saharan Africa, high spring NDVI in the Maghreb of North Africa, and frequent favorably directed tailwinds during migration periods are the three most important drivers of the size of the immigration to western Europe, while our atmospheric trajectory simulations demonstrate regular opportunities for wind-borne trans-Saharan movements. The effects of sub-Saharan vegetative productivity and wind conditions confirm that painted lady populations on either side of the Sahara are linked by regular mass migrations, making this the longest annual insect migration circuit so far known. Our results provide a quantification of the environmental drivers of large annual population fluctuations of an insect migrant and hold much promise for predicting invasions of migrant insect pests, disease vectors, and beneficial species.

Dispersal is a key process affecting population persistence and major factors affecting dispersal rates are the amounts, connectedness and properties of habitats in landscapes. We present new data on the butterfly Maniola jurtina in flower-rich and flower-poor habitats that demonstrates how movement and behaviour differ between sexes and habitat types, and how this effects consequent dispersal rates. Females had higher flight speeds than males, but their total time in flight was four times less. The effect of habitat type was strong for both sexes, flight speeds were ~ 2.5 × and ~ 1.7 × faster on resource-poor habitats for males and females, respectively, and flights were approximately 50% longer. With few exceptions females oviposited in the mown grass habitat, likely because growing grass offers better food for emerging caterpillars, but they foraged in the resource-rich habitat. It seems that females faced a trade-off between ovipositing without foraging in the mown grass or foraging without ovipositing where flowers were abundant. We show that taking account of habitat-dependent differences in activity, here categorised as flight or non-flight, is crucial to obtaining good fits of an individual-based model to observed movement. An important implication of this finding is that incorporating habitat-specific activity budgets is likely necessary for predicting longer-term dispersal in heterogeneous habitats, as habitat-specific behaviour substantially influences the mean (> 30% difference) and kurtosis (1.4 × difference) of dispersal kernels. The presented IBMs provide a simple method to explicitly incorporate known activity and movement rates when predicting dispersal in changing and heterogeneous landscapes. Electronic supplementary material The online version of this article (10.1007/s00442-020-04638-4) contains supplementary material, which is available to authorized users.

Species interactions have a spatio‐temporal component driven by environmental cues, which if altered by climate change can drive shifts in community dynamics. There is insufficient understanding of the precise time‐windows during which inter‐annual variation in weather drives phenological shifts and the consequences for mismatches between interacting species and resultant population dynamics – particularly for insects. We use a 20‐year study on a tri‐trophic system: sycamore Acer pseudoplatanus, two associated aphid species Drepanosiphum platanoidis and Periphyllus testudinaceus, and their hymenopteran parasitoids. Using a sliding window approach, we assess climatic drivers of phenology in all three trophic levels. We quantify the magnitude of resultant trophic mismatches between aphids and their plant hosts and parasitoids, and then model the impacts of these mismatches, direct weather effects and density dependence on local‐scale aphid population dynamics. Warmer temperatures in mid‐March to late‐April were associated with advanced sycamore budburst, parasitoid attack and (marginally) D. platanoidis emergence. The precise time‐window during which spring weather advances phenology varies considerably across each species. Crucially, warmer temperatures in late winter delayed the emergence of both aphid species. Seasonal variation in warming rates thus generate marked shifts in the relative timing of spring events across trophic levels and mismatches in the phenology of interacting species. Despite this, we found no evidence that aphid population growth rates were adversely impacted by the magnitude of mismatch with their host plants or parasitoids, or direct impacts of temperature and precipitation. Strong density dependence effects occurred in both aphid species and probably buffered populations, through density dependent compensation, from adverse impacts of the marked inter‐annual climatic variation that occurred during the study period. These findings explain the resilience of aphid populations to climate change and uncover a key mechanism, warmer winter temperatures delaying insect phenology, by which climate change drives asynchronous shifts between interacting species.

1. Measuring functional connectivity, the ability of species to move between resource patches, is essential for conservation in fragmented landscapes. However, current methods are highly time consuming and expensive. 2. Population synchrony- the correlation in time series of counts between two long-term population monitoring sites, has been suggested as a possible proxy measure of functional connectivity. To date, population synchrony has been shown to correlate with proxies for movement frequency such as the coverage of suitable habitat types in intervening landscapes, and also least cost distances around hostile land cover types. 3. This provides tentative evidence that synchrony is directly driven by movements of the focal species, but an alternative explanation is that these land cover types affect the movement of interacting species (e.g. natural enemies of the focal species) which can also drive synchronous population dynamics. Therefore, what is needed is a test directly relating population synchrony to movement frequencies of a focal species. 4. Here we use data from a 21 year mark-release-recapture study and show that population synchrony does indeed predict movements of a focal butterfly species Boloria eunomia (Esper). 5. There is growing evidence that population synchrony can be a useful conservation tool to measure functional connectivity.

Background Understanding the factors influencing movement is essential to forecasting species persistence in a changing environment. Movement is often studied using mechanistic models, extrapolating short-term observations of individuals to longer-term predictions, but the role of weather variables such as air temperature and solar radiation, key determinants of ectotherm activity, are generally neglected. We aim to show how the effects of weather can be incorporated into individual-based models of butterfly movement thus allowing analysis of their effects. Methods We constructed a mechanistic movement model and calibrated it with high precision movement data on a widely studied species of butterfly, the meadow brown (Maniola jurtina), collected over a 21-week period at four sites in southern England. Day time temperatures during the study ranged from 14.5 to 31.5 °C and solar radiation from heavy cloud to bright sunshine. The effects of weather are integrated into the individual-based model through weather-dependent scaling of parametric distributions representing key behaviours: the durations of flight and periods of inactivity. Results Flight speed was unaffected by weather, time between successive flights increased as solar radiation decreased, and flight duration showed a unimodal response to air temperature that peaked between approximately 23 °C and 26 °C. After validation, the model demonstrated that weather alone can produce a more than two-fold difference in predicted weekly displacement. Conclusions Individual Based models provide a useful framework for integrating the effect of weather into movement models. By including weather effects we are able to explain a two-fold difference in movement rate of M. jurtina consistent with inter-annual variation in dispersal measured in population studies. Climate change for the studied populations is expected to decrease activity and dispersal rates since these butterflies already operate close to their thermal optimum. Electronic supplementary material The online version of this article (10.1186/s40462-019-0171-7) contains supplementary material, which is available to authorized users.

Climate change is expected to increase the frequency of some climatic extremes. These may have drastic impacts on biodiversity, particularly if meteorological thresholds are crossed, leading to population collapses. Should this occur repeatedly, populations may be unable to recover, resulting in local extinctions. Comprehensive time series data on butterflies in Great Britain provide a rare opportunity to quantify population responses to both past severe drought and the interaction with habitat area and fragmentation. Here, we combine this knowledge with future projections from multiple climate models, for different Representative Concentration Pathways (RCPs), and for simultaneous modelled responses to different landscape characteristics. Under RCP8.5, which is associated with ‘business as usual’ emissions, widespread drought-sensitive butterfly population extinctions could occur as early as 2050. However, by managing landscapes and particularly reducing habitat fragmentation, the probability of persistence until mid-century improves from around zero to between 6 and 42% (95% confidence interval). Achieving persistence with a greater than 50% chance and right through to 2100 is possible only under both low climate change (RCP2.6) and semi-natural habitat restoration. Our data show that, for these drought-sensitive butterflies, persistence is achieved more effectively by restoring semi-natural landscapes to reduce fragmentation, rather than simply focusing on increasing habitat area, but this will only be successful in combination with substantial emission reductions.

The variability of populations over time is positively associated with their risk of local extinction. Previous work has shown that populations at the high-latitude boundary of species’ ranges show higher inter-annual variability, consistent with increased sensitivity and exposure to adverse climatic conditions. However, patterns of population variability at both high- and low- latitude species range boundaries have not yet been concurrently examined. Here, we assess the inter-annual population variability of 28 butterfly species between 1994 and 2009 at 351 and 18 sites in the United Kingdom and Catalonia, Spain, respectively. Local population variability is examined with respect to the position of the species’ bioclimatic envelopes (i.e. whether the population falls within areas of the ‘core’ climatic suitability or is a climatically ‘marginal’ population), and in relation to local landscape heterogeneity, which may influence these range location – population dynamic relationships. We found that butterfly species consistently show latitudinal gradients in population variability, with increased variability in the more northerly UK. This pattern is even more marked for southerly distributed species with ‘marginal’ climatic suitability in the UK but ‘core’ climatic suitability in Catalonia. In addition, local landscape heterogeneity did influence these range location – population dynamic relationships. Habitat heterogeneity was associated with dampened population dynamics, especially for populations in the UK. Our results suggest that promoting habitat heterogeneity may promote the persistence of populations at high-latitude range boundaries, which may potentially aid northwards expansion under climate warming. We did not find evidence that population variability increases towards southern range boundaries. Sample sizes for this region were low, but there was tentative evidence, in line with previous ecological theory, that local landscape heterogeneity may promote persistence in these retracting low-latitude range boundary populations. The variability of populations over time is positively associated with their risk of local extinction. Previous work has shown that populations at the high-latitude boundary of species’ ranges show higher inter-annual variability, consistent with increased sensitivity and exposure to adverse climatic conditions. However, patterns of population variability at both high- and low- latitude species range boundaries have not yet been concurrently examined. Here, we assess the inter-annual population variability of 28 butterfly species between 1994 and 2009 at 351 and 18 sites in the United Kingdom and Catalonia, Spain, respectively. Local population variability is examined with respect to the position of the species’ bioclimatic envelopes (i.e. whether the population falls within areas of the ‘core’ climatic suitability or is a climatically ‘marginal’ population), and in relation to local landscape heterogeneity, which may influence these range location – population dynamic relationships. We found that butterfly species consistently show latitudinal gradients in population variability, with increased variability in the more northerly UK. This pattern is even more marked for southerly distributed species with ‘marginal’ climatic suitability in the UK but ‘core’ climatic suitability in Catalonia. In addition, local landscape heterogeneity did influence these range location – population dynamic relationships. Habitat heterogeneity was associated with dampened population dynamics, especially for populations in the UK. Our results suggest that promoting habitat heterogeneity may promote the persistence of populations at high-latitude range boundaries, which may potentially aid northwards expansion under climate warming. We did not find evidence that population variability increases towards southern range boundaries. Sample sizes for this region were low, but there was tentative evidence, in line with previous ecological theory, that local landscape heterogeneity may promote persistence in these retracting low-latitude range boundary populations.

Global change drivers are known to interact in their effects on biodiversity, but much research to date ignores this complexity. As a consequence, there are problems in the attribution of biodiversity change to different drivers and, therefore, our ability to manage habitats and landscapes appropriately. Few studies explicitly acknowledge and account for interactive (i.e. non-additive) effects of land use and climate change on biodiversity. One reason is that the mechanisms by which drivers interact are poorly understood. We evaluate such mechanisms, including interactions between demographic parameters, evolutionary trade-offs and synergies and threshold effects of population size and patch occupancy on population persistence. Other reasons for the lack of appropriate research are limited data availability and analytical issues in addressing interaction effects. We highlight the influence that attribution errors can have on biodiversity projections and discuss experimental designs and analytical tools suited to this challenge. Finally, we summarise the risks and opportunities provided by the existence of interaction effects. Risks include ineffective conservation management; but opportunities also arise, whereby the negative impacts of climate change on biodiversity can be reduced through appropriate land management as an adaptation measure. We hope that increasing the understanding of key mechanisms underlying interaction effects and discussing appropriate experimental and analytical designs for attribution will help researchers, policy makers and conservation practitioners to better minimise risks and exploit opportunities provided by land use-climate change interactions.

The intensification of agricultural practices throughout the twentieth century has had large detrimental effects on biodiversity and these are likely to increase as the human population rises, with consequent pressure on land. To offset these negative impacts, agri-environment schemes have been widely implemented, offering financial incentives for land-owners to create or maintain favourable habitats that enhance or maintain biodiversity. While some evidence is available on the resulting species richness and abundance for groups such as natural predators, pollinating insects including butterflies and moths, this is costly to obtain and it is difficult to predict the effects of specific habitat designs. To alleviate this problem we here develop an individual-based model (IBM), modelling the detailed movement behaviour, foraging, and energy budget of a grassland butterfly Maniola jurtina Linn. in patches of varying dimensions and quality. The IBM is successfully validated against data on M. jurtina densities, movement behaviour, resource use, fecundity and lifespan in habitats of varying quality. We use the IBM to quantify the benefits for life-history outcomes of M. jurtina of increasing the quantity and the quality of field margins within agricultural landscapes. We find that increasing the quantity of field margin habitat from 1 to 3 ha per 100 ha, as recommended in agri-environment schemes, increases the average number of eggs laid across a two-week period by 60% and adds an extra day to the average lifespan. Similar effects are reported for variation in the quality of field margins. We discuss the implications of the result for modelling butterfly responses to management scenarios.

1.The phenology of many species has been shown to shift under climate change. However, because species respond at different rates, ecological communities may be disrupted leading to species extinctions and loss of ecosystem services. Hence, there is a need to monitor and understand phenological change. 2.Population data, gathered by standardised monitoring schemes, can be used to this end. However, such schemes require significant organisation and financial resources. Distribution data (georeferenced biological records with dates) are easier and cheaper to collect and may be an unexploited resource for phenology analyses. This would allow analysis of more taxa from more regions of the world. However, distribution data are potentially biased due to the unstandardised behaviour of biological recorders. 3.Here, the ability of distribution data record dates to accurately predict phenology is investigated by using the British butterfly fauna as a model system. We used the total number of distribution records per unit time across Great Britain as a proxy for butterfly abundance. Phenology metrics of mean flight date and flight period length were then calculated from the resulting abundance–time relationships for each year in a 15‐year time series. These estimates were validated against those generated from a standardised‐effort population monitoring scheme. 4.We analysed 1 078 328 records from 30 British butterflies and found that distribution data accurately predicted the mean flight date for 22 of the 30 species tested. Flight period length was only predicted accurately for seven of 30 species. 5.We found a nonlinear but consistent positive relationship between the accuracy of mean flight date estimates and sample size (number of records) at both inter‐ and intraspecific scales. Our results suggest that a threshold sample size of c. 6500 distribution records (430 per year) is a pragmatic compromise between accuracy and recording effort, leading to little loss of accuracy in phenology predictions (an average decrease in accuracy of 2·9 days was observed). 6.The results suggest that distribution data are a potentially useful resource for phenology research. This may allow practitioners to monitor particular regions and previously unstudied species relatively cheaply using existing mapping schemes.

1. Understanding the underlying ecological processes that govern population dynamics is essential for identifying the risk of extinction faced by a population. Ecological processes are driven by a number of different density-dependent and density-independent factors. Influential factors may vary between species and are often classified for large areas of a species' geographical range. 2. Here we test the hypothesis that these factors vary on a relatively small spatial scale across a species' range. The population dynamics of the large skipper butterfly Ochlodes sylvanus is investigated for each 100 km2 region within its British range. 3. Different forms of density dependence, including Allee effects, and different density-independent factors are found to influence population change significantly in different regions. The possible underlying mechanisms responsible for each are discussed. 4. In addition to this qualitative spatial variation in influencing factors, the relative contribution of density dependence and density-independent factors to temporal dynamics within each region is quantified. As the range of O. sylvanus is crossed from north-west to east, there appears to be a switch from density independence being more influential to density dependence having a greater impact on population change.

A variety of tools have emerged with the goal of mapping the current delivery of ecosystem services and quantifying the impact of environmental changes. An important and often overlooked question is how accurate the outputs of these models are in relation to empirical observations. In this paper we validate a hydrological ecosystem service model (InVEST Water Yield Model) using widely available data. We modelled annual water yield in 22 UK catchments with widely varying land cover, population and geology, and compared model outputs with gauged river flow data from the UK National River Flow Archive. Values for input parameters were selected from existing literature to reflect conditions in the UK and were subjected to sensitivity analyses. We also compared model performance between precipitation and potential evapotranspiration data sourced from global- and UK-scale datasets. We then tested the transferability of the results within the UK by additional validation in a further 20 catchments.Whilst the model performed only moderately with global-scale data (linear regression of modelled total water yield against empirical data; slope = 0.763, intercept = 54.45, R2 = 0.963) with wide variation in performance between catchments, the model performed much better when using UK-scale input data, with closer fit to the observed data (slope = 1.07, intercept = 3.07, R2 = 0.990). With UK data the majority of catchments showed less than 10% difference between measured and modelled water yield but there was a minor but consistent overestimate per hectare (86 m3/ha/year). Additional validation on a further 20 UK catchments was similarly robust, indicating that these results are transferable within the UK. These results suggest that relatively simple models can give accurate measures of ecosystem services. However, the choice of input data is critical and there is a need for further validation in other parts of the world.

In our recent Research Article “Individualistic sensitivities and exposure to climate change explain variation in species’ distribution and abundance changes” (1), we presented an analysis relating species-specific measures of sensitivity and exposure to climate, to species’ recent population changes. While our measure and interpretation of species’ climate sensitivity remain correct, we now recognize our interpretation of the exposure measure was inaccurate: Our climate models included an intercept, representing a nonzero average population growth rate; thus, the exposure measure incorporated not only climate effects but other nonclimatic—and potentially unmeasured climatic—effects as well. While our results still demonstrate that a significant proportion of variation in population trends can be explained by exposure and sensitivity, the correct interpretation of the exposure measure means that the explained variation is not solely due to climate. As such, our conclusion that a large proportion of variation in population changes can be explained by individualistic responses to climate is misleading. Given this, and to avoid confusion, we are wholly retracting the Research Article, and we apologize that this was not picked up sooner.

Most studies on the biological impact of climate change have focussed on incremental climate warming, rather than extreme events. Yet responses of species’ populations to climatic extremes may be one of the primary drivers of ecological change. We assess the resilience of individual populations in terms of their sensitivity to- and ability to recover from- environmental perturbation. We demonstrate the method using a model species, the ringlet butterfly Aphantopus hyperantus, and analyse the effects of an extreme drought event using data from 79 British sites over 10 yr. We find that populations crashed most severely in drier regions but, additionally, the landscape structure around sites influenced population responses. Larger and more connected patches of woodland habitat reduced population sensitivity to the drought event and also facilitated faster recovery. Having enough, sufficiently connected habitat appears essential for species’ populations to be resilient to the increased climatic variability predicted under future scenarios.

1. We use population synchrony as a new empirical method to assess functional connectivity – the permeability of landscapes given species dispersal attributes. Functional connectivity is important because well‐connected metapopulations are expected to be more resistant to stochastic events causing extinction. 2. A variety of factors impact population synchrony, and we attempt to account for several of these (shared climate, distance, habitat similarity and location within the range) before investigating impacts of the suitability of the landscape between populations – a proxy for permeability to dispersal. 3. For the Speckled Wood butterfly (Pararge aegeria), we find that population synchrony is positively correlated with landscape suitability, suggesting that synchrony might be used to measure functional connectivity. 4. The importance of landscape suitability for population synchrony shows a humped relationship with distance – suitability has no effect between 0 and 20 km, then showing a significant positive effect above 20 km but with reduced (still significant) effect from 160 to 200 km. This suggests that relatively close populations may exchange sufficient migrants for synchronisation, regardless of the matrix suitability. In contrast, more separate populations are synchronised only where the landscape permits functional connectivity, most likely through dispersal between intermediate stepping‐stone populations. 5. Synthesis and applications. We show that patterns of synchrony in long‐term monitoring data can be used to estimate functional connectivity of landscapes. As such, this technique might be used to test and prioritise the effectiveness of land management for conservation of species and to mitigate the effects of climate change.

1.?Current national and international frameworks for assessing threats to species have not been developed in the context of climate change, and are not framed in a way that recognises new opportunities that arise from climate change. 2.?The framework presented here separates the threats and benefits of climate change for individual species. Threat is assessed by the level of climate-related decline within a species’ recently occupied (e.g. pre-1970s) historical distribution, based on observed (e.g. repeat census) and/or projected changes (e.g. modelled bioclimate space). Benefits are assessed in terms of observed and/or projected increases outside the recently occupied historical range. 3.?Exacerbating factors (e.g. small population size, low dispersal capacity) that might increase levels of threat or limit expansion in response to climate change are taken into consideration within the framework. Protocols are also used to identify levels of confidence (and hence research and/or monitoring needs) in each species’ assessment. 4.?Observed and projected changes are combined into single measures of expected decline and increase, together with associated measures of confidence. We weight risk classifications towards information that is most certain. Each species is then placed in one of six categories (high risk, medium risk, limited impact, equivalent risks & benefits, medium benefit, high benefit) reflecting whether climate change is expected (or has been observed) to cause net declines or increases in the region considered, based on the balance of benefits and threats. 5.?We illustrate the feasibility of using the framework by applying it to (i) all British butterflies (N = 58 species) and (ii) an additional sample of British species: 18 species of plants, bats, birds and beetles. 6.?Synthesis. Our framework assesses net declines and increases associated with climate change, for individual species. It could be applied at any scale (regional, continental or global distributions of species), and complements existing conservation assessment protocols such as red-listing. Using observed and projected population and/or range data, it is feasible to carry out systematic conservation status assessments that inform the development of monitoring, adaptation measures and conservation management planning for species that are responding to climate change.

Understanding the mechanisms by which global climate change and habitat loss impact upon biodiversity is essential in order to mitigate any negative impacts. One such impact may be changes to population synchrony (defined as correlated fluctuations in the density of separate populations). It is well established that synchrony depends on both dispersal ability and correlated environmental conditions, for example shared climate. However, what is not clear is whether differences in habitat or position within a species' range also mediate synchrony. Since synchronous metapopulations are thought to be more extinction-prone, establishing the drivers of synchrony has clear conservation implications. Using three butterfly species (Maniola jurtina, Pyronia tithonus and Aphantopus hyperantus) we investigated the effects of habitat similarity and range position on population synchrony, after accounting for the effects of distance and climate. Range position was present in all minimum adequate models, though non-significant using Mantel randomization tests in one case. We show that M. jurtina and P. tithonus synchrony is not consistent across species' ranges, with marginal populations showing more synchronous dynamics. Increased climatic constraints on marginal populations, leading to a narrower range of suitable microhabitats may be responsible for this, which is supported by the result that habitat similarity between sites was also positively correlated with population synchrony. As the landscape becomes increasingly homogeneous, overall population synchrony may be expected to rise. We conclude that habitat modification and climate change have the capacity to drive changes in population synchrony that could make species more vulnerable to extinction.

Habitat heterogeneity is often suggested as being important for the stability of populations, and promoted as a means to aid the conservation of species, but the evidence for such an assumption is poor. Here we show that heterogeneous landscapes that contain a variety of suitable habitat types are associated with more stable population dynamics for 35 British butterfly species from 166 sites. In addition, topographic heterogeneity may also promote stability. Our results were robust to different measures of population variability, differences in mean abundance among sites, and to the spatial scale (radius 1-5 km around the centres of sites) at which landscapes were analysed. Responses to landscape heterogeneity differed among species; for more mobile 'wider-countryside' species, habitat heterogeneity at larger landscape scales had the strongest effect on population dynamics. We suggest that heterogeneous landscapes offer a greater range of resources and microclimates, which can buffer populations against climatic variation and generate more stable population dynamics.

Female Aphidecta obliterata consumed an average of 26.6 ± 5.8 Elatobium abietinum and males consumed an average of 19.9 ± 3.2 Elatobium abietinum, but there was no significant difference in the number consumed between the sexes. In Petri dish trials, the larval stages of A. obliterata and all stages of Adalia bipunctata appeared to exhibit a Type II response to prey density, although A. obliterata adults showed a more linear response to prey density. There was no significant difference between the functional responses of the 3rd instars of the two coccinellid species, but there was a significant difference between the responses shown by the 1st instars, with A. obliterata larvae consuming more than those of A. bipunctata, especially at low densities, suggesting that the two species respond differently to an increase in prey density. At low prey densities, adults and 4th instars of both species exhibited a similar response to an increase in prey density but at higher densities the 4th instars and adult stages of A. bipunctata showed higher attack rates when compared with the same stages of A. obliterata. Adult and 4th instar A. obliterata exhibited Type II functional responses on spruce sections. The 4th instar A. obliterata larva appeared to be a more effective predator than the adult of the species, and was more effective when compared with adult A. bipunctata at lower prey densities but A. bipunctata adults appeared to be a more effective predator at higher prey densities. The host plant affected the rate of consumption by adult A. obliterata as adults on Sitka spruce sections consumed significantly higher numbers of aphids than their counterparts on Norway spruce. This was most noticeable at densities above 16 aphids. The distributions of the two coccinellid species in the olfactometer were significantly affected by the presence of host plant material. Aphidecta obliterata adults were found in significantly higher numbers in the Sitka spruce chambers than the control chambers (those without plant material). Adalia bipunctata adults were found in significantly lower numbers in the Norway spruce chamber than the control chamber. Although A. bipunctata has a higher level of voracity than A. obliterata, the latter is more adapted to the spruce environment and the boom and bust population dynamics of E. abietinum.

Projected impacts of climate change on the populations and distributions of species pose a challenge for conservationists. In response, a number of adaptation strategies to enable species to persist in a changing climate have been proposed. Management to maximise the quality of habitat at existing sites may reduce the magnitude or frequency of climate-driven population declines. In addition large-scale management of landscapes could potentially improve the resilience of populations by facilitating inter-population movements. A reduction in the obstacles to species’ range expansion, may also allow species to track changing conditions better through shifts to new locations, either regionally or locally. However, despite a strong theoretical base, there is limited empirical evidence to support these management interventions. This makes it difficult for conservationists to decide on the most appropriate strategy for different circumstances. Here extensive data from long-term monitoring of woodland birds at individual sites are used to examine the two-way interactions between habitat and both weather and population count in the previous year. This tests the extent to which site-scale and landscape-scale habitat attributes may buffer populations against variation in winter weather (a key driver of woodland bird population size) and facilitate subsequent population growth. Our results provide some support for the prediction that landscape-scale attributes (patch isolation and area of woodland habitat) may influence the ability of some woodland bird species to withstand weather-mediated population declines. These effects were most apparent among generalist woodland species. There was also evidence that several, primarily specialist, woodland species are more likely to increase following population decline where there is more woodland at both site and landscape scales. These results provide empirical support for the concept that landscape-scale conservation efforts may make the populations of some woodland bird species more resilient to climate change. However in isolation, management is unlikely to provide a universal benefit to all species.

Populations at the high latitude edge of species' geographical ranges are thought to show larger interannual population fluctuations, with subsequent higher local extinction risk, than those within the 'core' climatic range. As climate envelopes shift northward under climate warming, however, we would expect populations to show dampened variability. We test this hypothesis using annual abundance indices from 19 butterfly species across 79 British monitoring sites between 1976 and 2009, a period of climatic warming. We found that populations in the latter (warmer) half of the recording period show reduced interannual population variability. Species with more southerly European distributions showed the greatest dampening in population variability over time. Our results suggest that increases in population variability occur towards climatic range boundaries. British sites, previously existing at the margins of suitable climate space, now appear to fall closer to the core climatic range for many butterfly species. © 2012 Blackwell Publishing Ltd.

1. Species distribution models (SDMs) are increasingly used in applied conservation biology, yet the predictive ability of these models is often tested only on detection/non‐detection data. The probability of long‐term population persistence, however, depends not only upon patch occupancy but upon more fundamental population parameters such as mean population density and stability over time. 2. Here, we test estimated probability of occurrence scores generated from SDMs built using species occupancy data against independent empirical data on population density and stability for 20 bird and butterfly species across 1941 sites over 15 years. We devised a measure of population stability over time which was independent of mean density and time‐series duration, yet positively correlated with risk of local extinction. This may be a useful surrogate measure of population persistence for use in applied conservation. 3. We found that probability of occurrence scores were significantly positively correlated with mean population density for both butterflies and birds. In contrast, probability of occurrence scores were at best weakly positively correlated with population stability. Referring to established ecological theory, we discuss why SDMs may be appropriate for predicting population density but not stability. 4. Synthesis and applications. Species distribution models are often constructed using species occupancy data because, for the majority of species and regions, these are the best data available. The models are then often used for projecting species’ distributions in the future and identifying areas where management could be targeted to improve species’ prospects. However, our results suggest that an overreliance on these SDMs may result in an exclusive focus on landscape management approaches that promote patch occupancy and density, but may overlook features important for long‐term population persistence such as population stability. Other landscape metrics that take into account habitat heterogeneity or configuration may be required to predict population stability. To understand species persistence under rapid environmental change, count data from standardised monitoring schemes are an invaluable resource. These data provide additional insights into the factors affecting species’ extinction risks, which cannot easily be inferred from species’ occupancy data.

This study investigates the sensitivity of local synchrony to movement patterns of the Ringlet butterfly (Aphantopus hyperantus). We examine whether population synchrony, describing the correlated fluctuations of conspecific populations, may prove an effective surrogate measure for monitoring functional connectivity in this species without the requirement of exhaustive sampling. We compared the effect on population synchrony of two different distance measures, direct (Euclidean) distance and distance via woodland rides and edges, and also of habitat matrix composition. Population synchrony of A. hyperantus was calculated as the pairwise correlation between population time-series using 20 years of data from UK butterfly monitoring scheme transects. Local population synchrony was better explained by distance via woodland edges than direct distance, especially for woodland-dominated transects. These results are consistent with mark-recapture data previously collected on the Ringlet butterfly. The results indicate a sensitivity of population synchrony to butterfly local dispersal behaviour, particularly, to the use of habitat corridors and other functional dispersal routes. Population synchrony is considered to have potential as a surrogate measure of functional connectivity. With development, this method could become a valuable conservation tool for identifying important landscape features which promote species’ connectivity.

Climate warming threatens the survival of species at their warm, trailing-edge range boundaries but also provides opportunities for the ecological release of populations at the cool, leading edges of their distributions. Thus, as the climate warms, leading-edge populations are expected to utilize an increased range of habitat types, leading to larger population sizes and range expansion. Here, we test the hypothesis that the habitat associations of British butterflies have expanded over three decades of climate warming. We characterize the habitat breadth of 27 southerly distributed species from 77 monitoring transects between 1977 and 2007 by considering changes in densities of butterflies across 11 habitat types. Contrary to expectation, we find that 20 of 27 (74%) butterfly species showed long-term contractions in their habitat associations, despite some short-term expansions in habitat breadth in warmer-than-usual years. Thus, we conclude that climatic warming has ameliorated habitat contractions caused by other environmental drivers to some extent, but that habitat degradation continues to be a major driver of reductions in habitat breadth and population density of butterflies.

Analysis of butterfly and moth species shows that responses to climate change may be more predictable than previously recognized., The responses of animals and plants to recent climate change vary greatly from species to species, but attempts to understand this variation have met with limited success. This has led to concerns that predictions of responses are inherently uncertain because of the complexity of interacting drivers and biotic interactions. However, we show for an exemplar group of 155 Lepidoptera species that about 60% of the variation among species in their abundance trends over the past four decades can be explained by species-specific exposure and sensitivity to climate change. Distribution changes were less well predicted, but nonetheless, up to 53% of the variation was explained. We found that species vary in their overall sensitivity to climate and respond to different components of the climate despite ostensibly experiencing the same climate changes. Hence, species have undergone different levels of population “forcing” (exposure), driving variation among species in their national-scale abundance and distribution trends. We conclude that variation in species’ responses to recent climate change may be more predictable than previously recognized.