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Habitat loss and climate change are key drivers of global biodiversity declines but their relative importance has rarely been examined. We attempted to attribute spatially divergent population trends of two Afro‐Palaearctic migrant warbler species, Willow Warbler Phylloscopus trochilus and Common Chiffchaff Phylloscopus collybita, to changes in breeding grounds climate or habitat. We used bird counts from over 4000 sites across the UK between 1994 and 2017, monitored as part of the BTO/JNCC/RSPB Breeding Bird Survey. We modelled Willow Warbler and Common Chiffchaff population size and growth in relation to habitat, climate and weather. We then used the abundance model coefficients and observed environmental changes to determine the extent to which spatially varying population trends in England and Scotland were consistent with attribution to climate and habitat changes. Both species' population size and growth correlated with habitat, climate and weather on their breeding grounds. Changes in habitat, in particular woodland expansion, could be linked to small population increases for both species in England and Scotland. Both species' populations correlated more strongly with climate than weather, and both had an optimum breeding season temperature: 11°C for Willow Warbler and around 13.5°C for Common Chiffchaff (with marginally different predictions from population size and growth models). Breeding ground temperature increases, therefore, had the potential to have caused some of the observed Willow Warbler declines in England (where the mean breeding season temperature was 12.7°C) and increases in Scotland (mean breeding season temperature was 10.2°C), and some of the differential rates of increase for Common Chiffchaff. However, much of the variation in species' population abundance and trends were not well predicted by our models and could be due to other factors, such as species interactions, habitat and climate change in their wintering grounds and on migration. This study provides evidence that the effect of climate change on a species may vary spatially and may switch from being beneficial to being detrimental if a temperature threshold is exceeded. [ABSTRACT FROM AUTHOR]

Across society there is pressure to assess and reduce carbon emissions to meet the obligations of the Paris Agreement and the Glasgow Climate Pact. Within the science community, there is increasing awareness of the carbon footprint of research activities, but to date there is no consideration of emissions associated with biodiversity monitoring.Biodiversity monitoring, often delivered through citizen science schemes, is key to assessing environmental change impacts and mitigation. However, attributes of rigorously designed schemes such as randomisation and high recording effort can require volunteers to undertake regular travel, raising two important questions: (a) is biodiversity monitoring reliant on volunteers with private vehicles?; and (b) what is the carbon footprint of a typical monitoring scheme?This study focussed on travel associated with participation in the UK Breeding Bird Survey. The BBS involves twice‐annual surveys of a stratified random sample of 1‐km squares across the United Kingdom, providing population trends for c. 120 terrestrial bird species with data used widely in policy and research. Using coverage information from 2019, we calculated road distances from volunteers' home addresses to their squares and sought information on travel methods using an online questionnaire (54% response rate).In 2019, 2765 volunteers made 7520 visits to 3914 1‐km squares, travelling over 286,000 km in the process. Travel required to visit individual squares was highly skewed and differed geographically and according to mode of travel. Eighty‐eight per cent of squares were accessed by private car, with conventionally fuelled vehicles accounting for 95% of these. Active travel accounted for 10% of visits and public transport only 1.4%. We estimate the total emissions produced to achieve BBS coverage in 2019 to be at least 46.8 tonnes CO2e.These results indicate a heavy reliance on access to private vehicles, creating a barrier to future participation, especially if pathways to decarbonisation involve reduced car ownership. Furthermore, they indicate the scale of carbon emissions likely to be produced by the monitoring sector. We discuss possible pathways to decarbonise monitoring schemes but stress that we do not wish to criticise the travel decisions of individual volunteers: the onus on decarbonisation lies firmly with the organisers of monitoring schemes. Read the free Plain Language Summary for this article on the Journal blog. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2006.07.001 Byline: Robin M. Fuller (a), Bernard J. Devereux (a), Simon Gillings (b), Ross A. Hill (c), Gabriel S. Amable (a) Keywords: Bird; Habitat; Map; Remote sensing; Biodiversity; Landscape; Ecology; Modelling Abstract: This paper develops a comprehensive and objective picture of bird distributions relative to habitats across Britain. Bird species presence/absence data from an extensive field survey and habitat data from the remotely sensed UK Land Cover Map 2000 were analysed in 36,920 tetrads (2kmx2km) across Britain (a 65% sample of Britain's c. 240000km.sup.2). Cluster analysis linked birds to generalised landscapes based on distinctive habitat assemblages. Maps of the clusters showed strong regional patterns associated with the habitat assemblages. Cluster centroid coordinates for each bird species and each habitat were combined across clusters to derive individualised bird-habitat preference indices and examine the importance of individual habitats for each bird species. Even rare species and scarce habitats showed successful linkages. Results were assessed against published accounts of bird-habitat relations. Objective corroboration strongly supported the associations. Relatively scarce coastal and wetland habitats proved particularly important for many birds. However, extensive arable farmland and woodland habitats were also favoured by many species, despite reported declines in bird numbers in these habitats. The fact that habitat-specialists do not or cannot move habitat is perhaps a reason for declining numbers where habitats have become unsuitable. This study showed that there are unifying principles determining bird-habitat relations which apply and can be quantified at the national scale, and which corroborate and complement the cumulative knowledge of many and varied surveys and ecological studies. This 'generality' suggests that we may be able, reliably and objectively, to integrate and scale up such disparate studies to the national scale, using this generalised framework. It also suggests the potential for a landscape ecology approach to bird-habitat analyses. Such developments will be important steps in building models to develop and test the sustainable management of landscapes for birds. Author Affiliation: (a) University of Cambridge, Unit for Landscape Modelling, Sir William Hardy Building, Downing Site, Tennis Court Road, Cambridge CB2 1QB, UK (b) British Trust for Ornithology, The Nunnery, Thetford, Norfolk IP24 2PU, UK (c) Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire PE28 2LS, UK Article History: Received 6 July 2005; Revised 8 May 2006; Accepted 12 July 2006

Migratory birds are subject to many pressures during their life cycle and many are declining as a consequence. Evidence from North America shows that for species that migrate at night, bright artificial light sources associated with urban areas can disrupt natural movement patterns, leading to direct and indirect fitness consequences. Comparable evidence for species and urban areas in Europe is limited. This study aimed to measure the response of nocturnally migrating thrushes to artificial light at night in the UK. We used passive acoustic recorders deployed across a gradient of artificial lighting to record the flight calls of three thrush species, with an expectation of greater call rates over brightly lit areas. We trained a convolutional neural network automatically to locate and identify thrush calls in the audio recordings, achieving area under the curve (AUC) values in withheld validation data of 0.93–0.98, and recall on independent field data of 85–94%, depending on species. Seasonal patterns of call rates were positively correlated across sites but there were large differences in absolute rates between sites. Call rates were up to five times higher over the brightest urban areas compared with darker villages, suggesting a strong phototaxic effect of artificial light at night on migratory thrushes. These results confirm that monitoring of flight calls can provide valuable information on the timing of nocturnal migration, but that the effects of artificial lighting must be taken into account in any comparisons of abundance across sites. European cities are not blighted by mass mortality of migrants striking illuminated buildings; even so, these results show that nocturnal migrants are influenced by light pollution. Ascertaining whether this has fitness consequences is a priority so as to inform the design and illumination of future urban areas. [ABSTRACT FROM AUTHOR]

Functional diversity metrics based on species traits are widely used to investigate ecosystem functioning. In theory, such metrics have different implications depending on whether they are calculated from traits mediating responses to environmental change (response traits) or those regulating function (effect traits), yet trait choice in diversity metrics is rarely scrutinized.Here, we compile effect and response traits for British bird species supplying two key ecological services—seed dispersal and insect predation—to assess the relationship between functional diversity and both mean and stability of community abundance over time.As predicted, functional diversity correlates with stability in community abundance of seed dispersers when calculated using response traits. However, we found a negative relationship between functional diversity and mean community abundance of seed dispersers when calculated using effect traits. Subsequently, when combining all traits together, we found inconsistent results with functional diversity correlating with reduced stability in insectivores, but greater stability in seed dispersers.Our findings suggest that trait choice should be considered more carefully when applying such metrics in ecosystem management. A free Plain Language Summary can be found within the Supporting Information of this article. [ABSTRACT FROM AUTHOR]

COVID-19 restrictions significantly biased BTO/JNCC/RSPB Breeding Bird Survey coverage across the UK allowing indicative trends to be produced for approximately one-third of species in England only. To investigate the effect that COVID-19 restrictions had on participation in and coverage of the Breeding Bird Survey (BBS), and to quantify the likely impacts on population change reporting based on 2020 data. We determined geographic, seasonal, and habitat coverage for the BBS in 2020 and compared this to previous years, and quantified the scale of biases and reductions in sample size for target species. We degraded existing BBS data (1994–2019) to simulate 2020 coverage and produced population change estimates using three methods applied to the complete and degraded data to assess the impacts of 2020 coverage on emergent trends. In 2020, 49% fewer survey squares were visited compared to 2019. Reductions were greatest in Wales, Scotland, and Northern Ireland, and in the early breeding season, when 90% fewer visits were made. The few early visits completed were on atypical dates and showed marked habitat biases. Individual species were detected in 23–96% fewer squares than normal. Population change estimates derived using routine trend models were negatively biased in up to 96% of species, with errors greatest for species normally detected on early visits. Alternative trend models using visit-specific parameterization or focussing only on late season visits overcame coverage biases for some species. Lockdown restrictions associated with the COVID-19 outbreak meant it was not possible to produce population trend information for UK, Wales, Scotland, or Northern Ireland in 2020. Indicative long-term trends could be produced in England only for a subset of about 40 species. We recommend managers of citizen science schemes undertake similar analyses to assess the scale of coverage biases when unforeseen events cause temporary, but substantial changes, in sampling effort. [ABSTRACT FROM AUTHOR]

Urban expansion poses a major threat to wildlife populations. Biodiversity‐friendly urban landscapes could deliver benefits for both wildlife and people, by incorporating conservation and ecosystem services objectives. Well‐designed urban developments could also soften the ecological impacts of urbanization. However, delivering urban landscapes that integrate biodiversity requirements effectively remains challenging.Ecological models, designed to predict wildlife population responses to alternative urban designs, could prove effective in supporting the creation of biodiversity‐friendly urban landscapes. Here, we combine national‐scale bird abundance data with high resolution, spatially explicit habitat data to characterize relationships between bird densities and urban landscape form in Britain. From these analyses and cross validation, we evaluate the potential for well‐parameterized, species‐specific models to be used to predict bird densities in novel or modified urban areas.Our analyses indicate that responses of bird abundance to urban habitat are species‐specific and complex, with few variables consistently affecting a large proportion of species. However, contiguous areas of greenspace within urban sites are preferential for accommodating breeding birds, compared to a more fragmented arrangement of multiple, small greenspace patches. In combination, the bird‐habitat relationships identified could successfully predict observed variation in abundance for most bird species considered.Further evaluation of habitat descriptor variables, spatial scales of species' habitat use and analytical modelling approaches may be needed to improve the predictive ability of bird‐habitat models for certain species, particularly waterbirds and those observed less frequently in urban areas.Synthesis and applications. We modelled breeding bird abundance in built‐up areas with respect to the characteristics and contexts of urban environments. While most variables were important for multiple species, responses overall were species‐specific, so simple assemblage metrics, like diversity, will not describe the variation in bird communities well. However, the results illustrate the potential of an evidence‐based, spatially explicit evaluation of urban development impacts on biodiversity, by predicting the consequences for bird numbers. Subject to verification of predictive ability, practitioners can apply the models to compare, for example, land‐sparing and sharing within developments, or to quantify the biodiversity requirements for effective offsetting. This would be facilitated by incorporation into an online tool allowing user‐determined input scenarios. [ABSTRACT FROM AUTHOR]

The transmission of pathogens across the interface between wildlife and livestock presents a challenge to the development of effective surveillance and control measures. Wild birds, especially waterbirds such as the Anseriformes and Charadriiformes are considered to be the natural hosts of Avian Influenza (AI), and are presumed to pose one of the most likely vectors for incursion of AI into European poultry flocks. We have developed a generic quantitative risk map, derived from the classical epidemiological risk equation, to describe the relative, spatial risk of disease incursion into poultry flocks via wild birds. We then assessed the risk for AI incursion into British flocks. The risk map suggests that the majority of AI incursion risk is highly clustered within certain areas of Britain, including in the east, the south west and the coastal north-west of England. The clustering of high risk areas concentrates total risk in a relatively small land area; the top 33% of cells contribute over 80% of total incursion risk. This suggests that targeted risk-based sampling in a relatively small geographical area could be a much more effective and cost-efficient approach than representative sampling. The generic nature of the risk map method, allows rapid updating and application to other diseases transmissible between wild birds and poultry. [ABSTRACT FROM AUTHOR]

Empirical evidence from many regions suggests that most species would be least negatively affected if human food demand were met through high‐yield agricultural production and conservation of nonfarm ecosystems (land sparing), rather than through wildlife‐friendly farming over a larger area (land sharing). However, repeated glaciation and a long history of agriculture may lead to different results in regions such as western Europe. We compared the consequences of land sparing and land sharing on breeding bird species in 2 lowland regions of England, The Fens, with 101 species, and Salisbury Plain, with 83. We derived density–yield responses for each species and then estimated regional population size under regional food production strategies, including land sharing and land sparing, a range of intermediate strategies, and a novel mixed strategy. In both regions, more species achieved maximum regional population size under land sparing than land sharing. In The Fens, the majority of birds were loser species (estimated to have smaller populations under all food production strategies than in the preagricultural baseline scenario), whereas in Salisbury Plain the majority were winners (smaller populations in the preagricultural baseline scenario). Loser species overwhelmingly achieved maximum regional population size under land sparing, whereas winner species achieved maximum regional population size under either land sharing or an intermediate strategy, highlighting the importance of defining which groups of species are the target of conservation. A novel 3‐compartment strategy (combining high‐yield farming, natural habitat, and low‐yield farming) often performed better than either land sharing or land sparing. Our results support intermediate or 3‐compartment land‐sparing strategies to maximize bird populations across lowland agricultural landscapes. To deliver conservation outcomes, any shift toward land sparing must, however, ensure yield increases are sustainable in the long term, do not entail increased negative effects on surrounding areas, and are linked to allocation of land for nature. Article impact statement: By freeing up land for conservation, high‐yield farming can maximize biodiversity outcomes even in long‐converted landscapes. [ABSTRACT FROM AUTHOR]

Motivation: We undertook large citizen science surveys of bird distributions (atlases) in Britain and Ireland, aimed at quantifying breeding bird distributions on a 20‐year cycle and wintering bird distributions on a c. 30‐year cycle. We use these to generate spatially referenced information on apparent changes in bird distributions over c. 40 years. Main type of variable contained: Detection of breeding and wintering bird species in grid squares during five periods, and changes in detection between periods. The combined distribution dataset contains 1,410,938 records detailing detections of 465 bird species in 3,880 grid cells in different periods. The combined distribution change dataset contains 1,297,791 records describing stability, apparent colonization or apparent extinction of individual species in grid squares between pairs of atlases spanning up to c. 40 years. Spatial location and grain: Grid squares (10 km × 10 km) containing land throughout Britain, Ireland, the Isle of Man and the Channel Islands. The majority of data are at 10‐km resolution, but data for rare species are summarized at 20‐ or 50‐km resolution to protect sensitive locations. Time period: The data represent summarized detection information derived from fieldwork during five periods: the breeding seasons 1968–1972, 1988–1991 and 2008–2011, and the winters 1981/1982–1983/1984 and 2007/2008–2010/2011. Major taxa studied and level of measurement: Birds; their distribution derived from citizen science surveys. Software format: Data are supplied as comma‐separated text files. [ABSTRACT FROM AUTHOR]

A key aim of ecology is to understand the drivers of ecological patterns, so that we can accurately predict the effects of global environmental change. However, in many cases, predictors are measured at a finer resolution than the ecological response. We therefore require data aggregation methods that avoid loss of information on fine‐grain heterogeneity.We present a data aggregation method that, unlike current approaches, reduces the loss of information on fine‐grain spatial structure in environmental heterogeneity for use with coarse‐grain ecological datasets. Our method contains three steps: (a) define analysis scales (predictor grain, response grain, scale‐of‐effect); (b) use a moving window to calculate a measure of variability in environment (predictor grain) at the process‐relevant scale (scale‐of‐effect); and (c) aggregate the moving window calculations to the coarsest resolution (response grain). We show the theoretical basis for our method using simulated landscapes and the practical utility with a case study. Our method is available as the grainchanger r package.The simulations show that information about spatial structure is captured that would have been lost using a direct aggregation approach, and that our method is particularly useful in landscapes with spatial autocorrelation in the environmental predictor variable (e.g. fragmented landscapes) and when the scale‐of‐effect is small relative to the response grain. We use our data aggregation method to find the appropriate scale‐of‐effect of land cover diversity on Eurasian jay Garrulus glandarius abundance in the UK. We then model the interactive effect of land cover heterogeneity and temperature on G. glandarius abundance. Our method enables us quantify this interaction despite the different scales at which these factors influence G. glandarius abundance.Our data aggregation method allows us to integrate variables that act at varying scales into one model with limited loss of information, which has wide applicability for spatial analyses beyond the specific ecological context considered here. Key ecological applications include being able to estimate the interactive effect of drivers that vary at different scales (such as climate and land cover), and to systematically examine the scale dependence of the effects of environmental heterogeneity in combination with the effects of climate change on biodiversity. [ABSTRACT FROM AUTHOR]

Capsule: Current UK distributions of non-native birds poorly match areas identified as being climatically suitable. Aims: Non-native species are spreading at unprecedented rates and though invasions are expected to increase under climate change, evidence for this is mixed. We assess climatic suitability throughout the UK based on the apparent match to the climate in species’ native ranges and investigate potential climatic limitation within the non-native range. Methods: Climate was characterized within polygons representing the native ranges of 167 potentially invasive species. Parts of the UK with current and future climate similar to that in the native range were deemed climatically suitable. The incidence of recent observations inside and outside suitable areas was used to test hypotheses about climatic limitation of non-native ranges. Results: Climate matching suggests that 69 of 167 non-native bird species could currently find climatically suitable areas for establishment in the UK. Future climate change would see this number increase by 14% by 2080. However, observed occurrences of non-native species in the UK were not significantly correlated to climatic suitability. Only 44 of the 69 species with suitable climate in the UK were present. Moreover, 85% of species observed in the UK had some UK occurrences in climatically unsuitable areas and for 57 species their entire UK range was in climatically unsuitable areas. Similar results were apparent for the subset of 12 species with established UK populations. Conclusions: Climate matching provides a relatively poor indication of the extent of current and future suitable areas because species can adapt to new climates or other factors constrain the native range and many climatically suitable areas are currently unoccupied. Improvements to climate matching techniques and ongoing surveillance are required to refine predictions to support effective management policies. [ABSTRACT FROM AUTHOR]

Over the last 20 years, species priorities for bird conservation in the UK have been guided by the in-depth 'Birds of Conservation Concern' assessments. For other wildlife, priorities tend to be informed by measures of extinction risk, generated by the IUCN Regional Red List process. We carried out the first formal IUCN assessment for birds in Great Britain. Of the 234 regularly occurring species assessed, 100 (43%) had at least one population (breeding or non-breeding) that qualified as Threatened using the standard IUCN Red List criteria and categories. Of 282 separate assessments of breeding or non-breeding populations, 39% qualified as Threatened (8% Critically Endangered, 14% Endangered, 17% Vulnerable) with a further 10% classified as Near Threatened. Both Golden Oriole Oriolus oriolus and Fieldfare Turdus pilaris were assessed as being Critically Endangered (Possibly Extinct) as breeding species. In addition, seven species were assessed as being already extinct (either Extinct or Regionally Extinct). The proportion of GB birds qualifying as Threatened was high compared with birds elsewhere in Europe and other taxonomic groups in GB. We believe that, if similar data were available, levels of extinction risk would be higher for other areas/taxa than is estimated currently. [ABSTRACT FROM AUTHOR]

Monitoring biodiversity over large spatial and temporal scales is crucial for assessing the impact of global changes and environmental mitigation measures. However, large-scale monitoring of invertebrates remains poorly developed despite the importance of these organisms in ecosystem functioning. Exciting possibilities applicable to professional and citizen science are offered by new recording techniques and methods of semi-automated species recognition based on sound detection., Static broad-spectrum detectors deployed to record throughout whole nights have been recommended for standardised acoustic monitoring of bats, but they have the potential to also collect acoustic data for other species groups. Large-scale deployment of such systems is only viable when combined with robust automated species identification algorithms. Here we examine the potential of such a system for detecting, identifying and monitoring bush-crickets (Orthoptera of the family Tettigoniidae). We use incidental sound recordings generated by an extensive citizen science bat survey and recordings from intensive site surveys to test a semi-automated step-wise method with a classifier for assigning species identities. We assess species' diel activity patterns to make recommendations for survey timing and interpretation of existing nocturnal data sets and consider the feasibility of determining site occupancy., Of six species of bush-crickets, the species classifier achieved over 85% accuracy for three, speckled bush-cricket, dark bush-cricket and Roesel's bush-cricket. It should be possible to automatically scan recordings for these species with minimal manual validation. Further refinement of the classifier is required for the three remaining species, in particular for the acoustically similar short-winged conehead and long-winged conehead. Diel activity patterns are species specific and it may be necessary to adjust the hours over which the detectors record to increase detection of key species, but this must be weighed against the costs in terms of increased memory and battery use and equipment security during daytime., We conclude that with logistical support and centralised semi-automated species identification it is now possible for the public to contribute to large-scale acoustic monitoring of Orthoptera while recording bats. Further innovation of sound classifier algorithms is needed and would be aided by improved reference sound libraries from multiple locations spanning species' ranges. [ABSTRACT FROM AUTHOR]

Capsule:Across Britain, breeding Eurasian CurlewNumenius arquataare less numerous and have shown greater population declines in areas with more arable farming, woodland cover and higher generalist predator abundance. Aims:We present the first national-scale analysis of the potential drivers of Curlew population change in Britain, which is needed to guide conservation action for this globally near-threatened, declining species. Methods:Breeding Bird Survey data and environmental predictors were used to model variation in Curlew abundance in 1995–99 and 2007–11, and population change between these periods. Results:Arable farming and woodland cover were negatively associated with Curlew abundance and population declines. Curlew abundance was positively associated with extent of protected area coverage and gamebird numbers. Abundance and population change were positively associated with cooler temperatures and higher summer rainfall, but negatively associated with numbers of generalist predators. Conclusions:We found support for the negative effects of intensive agriculture, forestry, increases in generalist predator populations and climate warming on Curlew abundance and population change. Effective site protection and measures to reduce generalist predator abundance may be important conservation measures, together with improving breeding habitat quality in the wider countryside. [ABSTRACT FROM PUBLISHER]

Climate change is increasingly altering the composition of ecological communities, in combination with other environmental pressures such as high-intensity land use. Pressures are expected to interact in their effects, but the extent to which intensive human land use constrains community responses to climate change is currently unclear. A generic indicator of climate change impact, the community temperature index ( CTI), has previously been used to suggest that both bird and butterflies are successfully 'tracking' climate change. Here, we assessed community changes at over 600 English bird or butterfly monitoring sites over three decades and tested how the surrounding land has influenced these changes. We partitioned community changes into warm- and cold-associated assemblages and found that English bird communities have not reorganized successfully in response to climate change. CTI increases for birds are primarily attributable to the loss of cold-associated species, whilst for butterflies, warm-associated species have tended to increase. Importantly, the area of intensively managed land use around monitoring sites appears to influence these community changes, with large extents of intensively managed land limiting 'adaptive' community reorganization in response to climate change. Specifically, high-intensity land use appears to exacerbate declines in cold-adapted bird and butterfly species, and prevent increases in warm-associated birds. This has broad implications for managing landscapes to promote climate change adaptation. [ABSTRACT FROM AUTHOR]

Species distribution models (SDMs) are one of the most important GIScience research areas in biogeography and are the primary means by which the potential effects of climate change on species’ distributions and ranges are investigated. Dispersal is an important ecological process for species responding to changing climates, however, SDMs and their subsequent spatial products rarely reflect accessibility to any future suitable environment. Dispersal-related movement can be confounded by factors that vary across landscapes and climates, as well as within and among species, and it has therefore remained difficult to parametrise in SDMs. Here we compared 20 models that have previously been used (or have the potential to be used) to represent dispersal processes in SDM to predict future range shifts in response to climate change. We assessed the different dispersal models in terms of their accuracy at predicting future distributions, as well as the uncertainty associated with their predictions. Atlas data for 50 bird species from 1988 to 1991 in Great Britain were treated as base distributions (t1), with the species–environment relationships extrapolated (using three commonly used statistical methods) to 2008–2011 (t2). Dispersal (in the form of the 20 different models) was simulated from the base distribution (t1) to 2008–2011 (t2). The results were then combined and used to identify locations that were both abiotically suitable (obtained from the statistical methods) and accessible (obtained from the dispersal models). The accuracy of these coupled projections was assessed with the 2008–2011 atlas data (the observed t2distribution). There was substantial variation in the accuracy of the different dispersal models, and in general, the more restrictive dispersal models (e.g. fixed rate dispersal) resulted in lower accuracy for the metrics which reward correct prediction of presences. Ensemble models of the dispersal methods (generated by combining multiple projection outcomes) were created for each species, and a new Ensemble Agreement Index (EAI), which ranges from 0 (no agreement among models) to 1 (full agreement among models) was developed to quantify uncertainty among the projections. EAI values ranged from 0.634 (some areas of disagreement and therefore medium uncertainty among dispersal models) to 0.999 (large areas of agreement and low uncertainty among dispersal models). The results of this research highlight the importance of incorporating dispersal and also illustrate that the method with which dispersal is simulated greatly impacts the projected future distribution. This has important implications for studies aimed at predicting the effects of changing environmental conditions on species’ distributions. [ABSTRACT FROM AUTHOR]

The timing of migration is one of the key life-history parameters of migratory birds. It is expected to be under strong selection, to be sensitive to changing environmental conditions and to have implications for population dynamics. However, most phenological studies do not describe arrival and departure phenologies for a species in a way that is robust to potential biases, or that can be clearly related to breeding populations. This hampers our ability to understand more fully how climate change may affect species' migratory strategies, their life histories and ultimately their population dynamics. Using generalized additive models ( GAMs) and extensive large-scale data collected in the UK over a 40-year period, we present standardized measures of migration phenology for common migratory birds, and examine how the phenology of bird migration has changed in the UK since the 1960s. Arrival dates for 11 of 14 common migrants became significantly earlier, with six species advancing their arrival by more than 10 days. These comprised two species, Blackcap Sylvia atricapilla and Chiffchaff Phylloscopus collybita, which winter closest to Britain in southern Europe and the arid northern zone of Africa, Common Redstart Phoenicurus phoenicurus, which winters in the arid zone, and three hirundines (Sand Martin Riparia riparia, House Martin Delichon urbicum and Barn Swallow Hirundo rustica), which winter in different parts of Africa. Concurrently, departure dates became significantly later for four of the 14 species and included species that winter in southern Europe (Blackcap and Chiffchaff) and in humid zones of Africa (Garden Warbler Sylvia borin and Whinchat Saxicola rubetra). Common Swift Apus apus was the exception in departing significantly earlier. The net result of earlier arrival and later departure for most species was that length of stay has become significantly longer for nine of the 14 species. Species that have advanced their timing of arrival showed the most positive trends in abundance, in accordance with previous studies. Related in part to earlier arrival and the relationship above, we also show that species extending their stay in Great Britain have shown the most positive trends. Further applications of our modelling approach will provide opportunities for more robust tests of relationships between phenological change and population dynamics than have been possible previously. [ABSTRACT FROM AUTHOR]

CapsuleThe breeding Woodcock population in Britain in 2013 was estimated at 55 241 males (95% CL: 41 806–69 004), suggesting a large-scale decline that is supported by 2 additional sources of data. AimsTo provide an updated estimate of the size of Britain's breeding Woodcock population, measure recent trends and identify spatial patterns of change. MethodsDisplaying male Woodcock were surveyed at a stratified sample of 834 randomly selected sites. Population estimates were compared with a baseline survey conducted in 2003 and the trend with data from annual Woodcock counts (2003–13) andBird Atlas 2007–11. ResultsWoodcock were estimated to be present at 22% of 1 × 1 km squares containing ≥10 ha of woodland, compared to 35% in 2003. The British population estimate fell by 29% between 2003 and 2013. The Atlas suggests that presence at the 10 × 10 km scale has declined by 56% between 1970 and 2010. Both data sources suggest regional variation in the rate of decline, with losses greatest in the West and South. ConclusionThe Woodcock's population size and breeding range appear to be declining severely across Britain. Regional variation in the rate of decline might be explained by the distribution of large continuous woodlands. [ABSTRACT FROM AUTHOR]

Many species are extending their leading-edge (cool) range margins polewards in response to recent climate change. In the present study, we investigated range margin changes at the northern (cool) range margins of 1573 southerly-distributed species from 21 animal groups in Great Britain over the past four decades of climate change, updating previous work. Depending on data availability, range margin changes were examined over two time intervals during the past four decades. For four groups (birds, butterflies, macromoths, and dragonflies and damselflies), there were sufficient data available to examine range margin changes over both time intervals. We found that most taxa shifted their northern range margins polewards and this finding was not greatly influenced by changes in recorder effort. The mean northwards range margin change in the first time interval was 23 km per decade ( N = 13 taxonomic groups) and, in the second interval, was 18 km per decade ( N = 16 taxonomic groups) during periods when the British climate warmed by 0.21 and 0.28 °C per decade, respectively. For the four taxa examined over both intervals, there was evidence for higher rate of range margin change in the more recent time interval in the two Lepidoptera groups. Our analyses confirm a continued range margin shift polewards in a wide range of taxonomic groups. [ABSTRACT FROM AUTHOR]

There is good evidence that species' distributions are shifting poleward in response to climate change and wide interest in the magnitude of such responses for scientific and conservation purposes. It has been suggested from the directions of climatic changes that species' distribution shifts may not be simply poleward, but this has been rarely tested with observed data. Here, we apply a novel approach to measuring range shifts on axes ranging through 360°, to recent data on the distributions of 122 species of British breeding birds during 1988-1991 and 2008-2011. Although previously documented poleward range shifts have continued, with an average 13.5 km shift northward, our analysis indicates this is an underestimate because it ignores common and larger shifts that occurred along axes oriented to the north-west and north-east. Trailing edges contracted from a broad range of southerly directions. Importantly, these results are derived from systematically collected data so confounding observer-effort biases can be discounted. Analyses of climate for the same period show that whilst temperature trends should drive species along a north-north-westerly trajectory, directional responses to precipitation will depend on both the time of year that is important for determining a species' distribution, and the location of the range margin. Directions of species' range centroid shift were not correlated with spatial trends in any single climate variable. We conclude that range shifts of British birds are multidirectional, individualistic and probably determined by species-specific interactions of multiple climate factors. Climate change is predicted to lead to changes in community composition through variation in the rates that species' ranges shift; our results suggest communities could change further owing to constituent species shifting along different trajectories. We recommend more studies consider directionality in climate and range dynamics to produce more appropriate measures of observed and expected responses to climate change. [ABSTRACT FROM AUTHOR]

CapsuleTrends in young woodland availability influenced population trends and abundance of Tree Pipit and Lesser Redpoll, but not 10-km square occupancy. AimsTo investigate whether changes in availability of young woodland could have driven population change, and trends in abundance and occupancy, of declining Tree Pipit and Lesser Redpoll populations in Britain. MethodsModelling approaches used annual population indices and woodland planting statistics. Abundance and occupancy change between two bird atlases were examined in relation to changes in woodland availability from two woodland inventories. ResultsEnglish declines were strongly associated with decreases in young coniferous woodland availability and less strongly with increases in young broadleaved woodland. Abundance was related to the area of young woodland in corresponding 10-km squares. Young woodland availability declined between forest inventories and species occupancy maintained in 10-km squares with more young woodland; however squares that showed retention or increases in occupancy showed higher reductions in woodland. ConclusionWe suggest declining availability of young coniferous woodland contributed to Tree Pipit and Lesser Redpoll population trends in England. Although likely to be the case in Scotland and Wales, the lack of sufficient temporal data inhibited our ability to test this properly. This work suggests that woodland availability was not the primary driver of Tree Pipit or Lesser Redpoll population trends. [ABSTRACT FROM AUTHOR]

CapsuleThe recent population decline of Whinchats has accelerated, including core breeding areas of Britain. Contrasting patterns of change with Stonechat suggest a large-scale environmental driver is affecting the entire Whinchat population. AimsTo explore broad geographical and landscape related differences in long-term patterns of population change in the Whinchat and Stonechat across Britain to identify candidate mechanisms of change. MethodsThe study uses 40 years of large-scale, long-term data from a series of three atlas studies to compare trends in range and abundance in Whinchats and Stonechats relative to landscape and weather variables. ResultsFor Whinchats there has been a long-term and accelerating decline in abundance, that includes stronghold areas of Britain. The Stonechat population has undergone a net gain in abundance with regional and altitudinal variations. These two very different patterns of change suggest the relative ubiquity of decline in Whinchats has a common source affecting the whole population. ConclusionsThe scale and magnitude of decline in Whinchats should stimulate a revision of the species conservation status in Britain, with renewed focus on studying the species' ecology across its breeding and winter range in order to determine the likely large-scale drivers of its decline. [ABSTRACT FROM PUBLISHER]