There has been widespread concern that neonicotinoid pesticides may be adversely impacting wild a... more There has been widespread concern that neonicotinoid pesticides may be adversely impacting wild and managed bees for some years, but recently attention has shifted to examining broader effects they may be having on biodiversity. For example in the Netherlands, declines in insectivorous birds are positively associated with levels of neonicotinoid pollution in surface water. In England, the total abundance of widespread butterfly species declined by 58% on farmed land between 2000 and 2009 despite both a doubling in conservation spending in the UK, and predictions that climate change should benefit most species. Here we build models of the UK population indices from 1985 to 2012 for 17 widespread butterfly species that commonly occur at farmland sites. Of the factors we tested, three correlated significantly with butterfly populations. Summer temperature and the index for a species the previous year are both positively associated with butterfly indices. By contrast, the number of hectares of farmland where neonicotinoid pesticides are used is negatively associated with butterfly indices. Indices for 15 of the 17 species show negative associations with neonicotinoid usage. The declines in butterflies have largely occurred in England, where neonicotinoid usage is at its highest. In Scotland, where neonicotinoid usage is comparatively low, butterfly numbers are stable. Further research is needed urgently to show whether there is a causal link between neonicotinoid usage and the decline of widespread butterflies or whether it simply represents a proxy for other environmental factors associated with intensive agriculture.
The responses of animals and plants to recent climate change vary greatly from species to species... more 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-...
ABSTRACT Agricultural expansion and intensification have been linked with losses of biodiversity ... more ABSTRACT Agricultural expansion and intensification have been linked with losses of biodiversity and disruption of key ecosystem services in farmed landscapes. A number of mitigation and adaptation strategies e.g. agri-environment schemes, have been implemented to counter these declines but their effectiveness has been questioned by conservationists as well as policy makers. A key concern is the lack of knowledge about how conservation efforts might best be directed; especially in terms of aligning the scale and type of implementation in different landscapes with the niche requirements and dynamics of different species and taxa. Here we focus on how the landscape context of farmed systems at different spatial scales determines the abundance of habitat generalist and specialist butterfly and moth species in southern England. We used butterfly data from 20 UK Butterfly Monitoring Scheme sites, supplemented with moth data from a light trap survey of 11 sites, in southern England where the predominant habitat type sampled is lowland calcareous grassland. Our results show that larger areas of semi-natural grassland generally support larger numbers and a greater species richness of butterflies and moths, but that the composition of the Lepidoptera fauna changes with habitat size depending on the diversity of habitats in the landscape, particularly at the larger spatial scale. Larger areas of grassland in less diverse landscapes result in a proportionally greater number and diversity of habitat specialists, whilst habitat diversity is important in maintaining numbers and diversity of more generalist wider countryside species. Large areas of single habitat types may only be economically maintained at the expense of habitat diversity. Whilst these sites may be important in promoting abundance and diversity of selected specialist species, they may be prone to lower overall species richness. This has implications for improving the design and implementation of agri-environment schemes aimed at providing suitable habitat in order to promote the abundance and diversity of Lepidoptera and other taxa.
Monitoring butterfly populations is an important means of measuring change in the environment as ... more Monitoring butterfly populations is an important means of measuring change in the environment as well as the state of habitats for biodiversity. It is also a useful way that both professional ecologists and volunteers can contribute to the conservation of butterflies and biodiversity. This manual describes how to set up butterfly monitoring, do the counts and report on them. 1) Butterflies can be monitored by anyone who has the time (one hour a week is enough) and is familiar with the butterfly species at the place where the counts have to be made. 2) Butterflies are counted along fixed routes, known as transects, which are divided into smaller sections. It is important that transects are not too long and close to your home, to make them easy to repeat. The details of the route should be written down so that it can be followed by other recorders in the future. 3) Butterflies should be counted throughout the butterfly season under good weather conditions that meet minimum criteria. C...
There is increasing evidence that the distributions of a large number of species are shifting wit... more There is increasing evidence that the distributions of a large number of species are shifting with global climate change as they track changing surface temperatures that define their thermal niche. Modelling efforts to predict species distributions under future climates have increased with concern about the overall impact of these distribution shifts on species ecology, and especially where barriers to dispersal exist. Here we apply a bio-climatic envelope modelling technique to investigate the impacts of climate change on the geographic range of ten cetacean species in the eastern North Atlantic and to assess how such modelling can be used to inform conservation and management. The modelling process integrates elements of a species' habitat and thermal niche, and employs “hindcasting” of historical distribution changes in order to verify the accuracy of the modelled relationship between temperature and species range. If this ability is not verified, there is a risk that inappro...
Phenology shifts are the most widely cited examples of the biological impact of climate change, y... more 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.
There has been widespread concern that neonicotinoid pesticides may be adversely impacting wild a... more There has been widespread concern that neonicotinoid pesticides may be adversely impacting wild and managed bees for some years, but recently attention has shifted to examining broader effects they may be having on biodiversity. For example in the Netherlands, declines in insectivorous birds are positively associated with levels of neonicotinoid pollution in surface water. In England, the total abundance of widespread butterfly species declined by 58% on farmed land between 2000 and 2009 despite both a doubling in conservation spending in the UK, and predictions that climate change should benefit most species. Here we build models of the UK population indices from 1985 to 2012 for 17 widespread butterfly species that commonly occur at farmland sites. Of the factors we tested, three correlated significantly with butterfly populations. Summer temperature and the index for a species the previous year are both positively associated with butterfly indices. By contrast, the number of hectares of farmland where neonicotinoid pesticides are used is negatively associated with butterfly indices. Indices for 15 of the 17 species show negative associations with neonicotinoid usage. The declines in butterflies have largely occurred in England, where neonicotinoid usage is at its highest. In Scotland, where neonicotinoid usage is comparatively low, butterfly numbers are stable. Further research is needed urgently to show whether there is a causal link between neonicotinoid usage and the decline of widespread butterflies or whether it simply represents a proxy for other environmental factors associated with intensive agriculture.
The responses of animals and plants to recent climate change vary greatly from species to species... more 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-...
ABSTRACT Agricultural expansion and intensification have been linked with losses of biodiversity ... more ABSTRACT Agricultural expansion and intensification have been linked with losses of biodiversity and disruption of key ecosystem services in farmed landscapes. A number of mitigation and adaptation strategies e.g. agri-environment schemes, have been implemented to counter these declines but their effectiveness has been questioned by conservationists as well as policy makers. A key concern is the lack of knowledge about how conservation efforts might best be directed; especially in terms of aligning the scale and type of implementation in different landscapes with the niche requirements and dynamics of different species and taxa. Here we focus on how the landscape context of farmed systems at different spatial scales determines the abundance of habitat generalist and specialist butterfly and moth species in southern England. We used butterfly data from 20 UK Butterfly Monitoring Scheme sites, supplemented with moth data from a light trap survey of 11 sites, in southern England where the predominant habitat type sampled is lowland calcareous grassland. Our results show that larger areas of semi-natural grassland generally support larger numbers and a greater species richness of butterflies and moths, but that the composition of the Lepidoptera fauna changes with habitat size depending on the diversity of habitats in the landscape, particularly at the larger spatial scale. Larger areas of grassland in less diverse landscapes result in a proportionally greater number and diversity of habitat specialists, whilst habitat diversity is important in maintaining numbers and diversity of more generalist wider countryside species. Large areas of single habitat types may only be economically maintained at the expense of habitat diversity. Whilst these sites may be important in promoting abundance and diversity of selected specialist species, they may be prone to lower overall species richness. This has implications for improving the design and implementation of agri-environment schemes aimed at providing suitable habitat in order to promote the abundance and diversity of Lepidoptera and other taxa.
Monitoring butterfly populations is an important means of measuring change in the environment as ... more Monitoring butterfly populations is an important means of measuring change in the environment as well as the state of habitats for biodiversity. It is also a useful way that both professional ecologists and volunteers can contribute to the conservation of butterflies and biodiversity. This manual describes how to set up butterfly monitoring, do the counts and report on them. 1) Butterflies can be monitored by anyone who has the time (one hour a week is enough) and is familiar with the butterfly species at the place where the counts have to be made. 2) Butterflies are counted along fixed routes, known as transects, which are divided into smaller sections. It is important that transects are not too long and close to your home, to make them easy to repeat. The details of the route should be written down so that it can be followed by other recorders in the future. 3) Butterflies should be counted throughout the butterfly season under good weather conditions that meet minimum criteria. C...
There is increasing evidence that the distributions of a large number of species are shifting wit... more There is increasing evidence that the distributions of a large number of species are shifting with global climate change as they track changing surface temperatures that define their thermal niche. Modelling efforts to predict species distributions under future climates have increased with concern about the overall impact of these distribution shifts on species ecology, and especially where barriers to dispersal exist. Here we apply a bio-climatic envelope modelling technique to investigate the impacts of climate change on the geographic range of ten cetacean species in the eastern North Atlantic and to assess how such modelling can be used to inform conservation and management. The modelling process integrates elements of a species' habitat and thermal niche, and employs “hindcasting” of historical distribution changes in order to verify the accuracy of the modelled relationship between temperature and species range. If this ability is not verified, there is a risk that inappro...
Phenology shifts are the most widely cited examples of the biological impact of climate change, y... more 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.
Recent changes in the seasonal timing (phenology) of familiar biological events have been one of ... more Recent changes in the seasonal timing (phenology) of familiar biological events have been one of the most conspicuous signs of climate change. However, the lack of a standardized approach to analysing change has hampered assessment of consistency in such changes among different taxa and trophic levels and across freshwater, terrestrial and marine environments. We present a standardized assessment of 25 532 rates of phenological change for 726 UK terrestrial, freshwater and marine taxa. The majority of spring and summer events have advanced, and more rapidly than previously documented. Such consistency is indicative of shared large scale drivers. Furthermore, average rates of change have accelerated in a way that is consistent with observed warming trends. Less coherent patterns in some groups of organisms point to the agency of more local scale processes and multiple drivers. For the first time we show a broad scale signal of differential phenological change among trophic levels; across environments advances in timing were slowest for secondary consumers, thus heightening the potential risk of temporal mismatch in key trophic interactions. If current patterns and rates of phenological change are indicative of future trends, future climate warming may exacerbate trophic mismatching, further disrupting the functioning, persistence and resilience of many ecosystems and having a major impact on ecosystem services.
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