The two main themes of The State of the UK’s Birds report (SUKB) 2015 are farmland birds (illustrated by this year’s cover of a Lapwing) - a group that as a whole continues to decline, and how strong partnerships can help to reverse the fortunes of some of our farmland specialists - such as the Yellowhammer, currently faring well in Scotland; and species such as Tree Sparrow and Lapwing, all of which have shown evidence of positive responses on farms under Environmental Stewardship. Over the last four decades, declines in farmland birds have been shown to be due to a number of factors including the loss of mixed farming; increased use of pesticides; changes in grassland management and changes in crop type and the timing of management. The effects of predation and climate change, and threats to migratory species away from their breeding grounds are also playing a role. Agri-environment schemes provide the primary mechanism for improving conditions for farmland birds so how these are delivered in the future is critical. Other future challenges for farmland birds include emerging diseases and the development and use of new pesticides such as neonicotinoids. The importance of volunteer data Volunteer data continue to provide most of the information used to update the trends reported for the UK, one of the two key examples being the more than 2500 volunteer participants in the Breeding Bird Survey. Providing annual population trends for more than 100 species, the BBS results highlight six species with severe declines just since 1995: Turtle Dove, Willow Tit, Wood Warbler, Grey Partridge, Pied Flycatcher and Whinchat. Four of these species are long-distance migrants and three are woodland specialists. Counts by volunteers at more than 2,200 wetland sites at monthly intervals for the Wetland Bird Survey provide the information to report on wintering population trends in 46 species or races of waterbirds including ducks, geese, swans, waders, grebes, rails and cormorants. After two decades of increase, the wintering waterbird indicator has been declining over the last decade, particularly among species such as Turnstone and Purple Sandpiper, characteristic of the non-estuarine coasts. "Without the dedication of thousands of volunteers, and partnerships between a whole suite of organisations, bird monitoring could not function on the scale illustrated by the latest the 'State of the UK's Birds'. From monitoring comes conservation action, and it is uplifting to read examples of partnership projects working to conserve the UK's birds. The latest SUKB celebrates both volunteer effort and innovative partnerships, something volunteers and partnership organisations should be proud of. Now to continue this great work..." Sarah Harris, Breeding Bird Survey National Organiser. Scarce and rare breeding species SUKB 2015 once again includes a summary of trends in scarce and rare breeding species, drawn mainly from the annual reports of the Rare Breeding Bird Panel and the SCARABBS programme of periodic surveys. A number of these birds are perilously close to extinction in the UK: one species, the Wryneck, may be already, as the last known breeding record was in 2002 and the Golden Oriole has not bred since 2009. Red-backed Shrikes appeared to be going the same way, but successful breeding in Devon and the Highlands in recent years gives us some cause for hope. While Red-backed Shrikes and Wrynecks were once found breeding across large parts of the UK, species such as Purple Sandpipers, Savi’s Warblers, Marsh Warblers, Redwings and Fieldfares have never, to the best of our knowledge, been anything more than rare breeders. The UK lies at the edge of their breeding ranges, and their fortunes here are dependent on how they fare elsewhere in Europe. Apart from input to international conservation policy, the best we can do is to protect the few pairs that do breed.

New research involving the BTO shows how bird populations are consistently responding to the effects of climate change on two continents. The study, led by the University of Durham, analysed data on abundance collected between 1980 and 2010 from 145 common species in Europe, and 380 in North America. UK data includes records collected by volunteers taking part in the BTO/JNCC/RSPB Breeding Bird Survey and its predecessor the Common Birds Census, both coordinated by the BTO. Using existing information on bird distributions, the authors divided the species into those that predicted to respond favourably to climate change by gaining climatically-suitable range in the future (such as Cetti’s Warbler or European Bee-eater) and those predicted to respond negatively by losing climatically suitable range (such as Brambling and Willow Tit). The next step was to aggregate population trends for each group. This showed that species expected to respond favourably had shown significant increases in America and were stable in Europe whereas species expected to respond negatively had shown significant declines in Europe and were broadly stable in America. For each continent, the divergence between the two groups of species was combined to produce a single new indicator called the ‘climate impact indicator (CII)’. Despite differences between the continents in many other environmental conditions, the CII for Europe and for North America are remarkably similar, and closely correspond to recorded changes in climate such as temperature. Obviously, birds respond to many other pressures, especially land use change such as agricultural intensification and changes in forests. The value of this approach is that it focuses on the impact of climate change, its effects clearly demonstrated by the new indicator. This study uses data from a large suite of species and broad geographic scales. Importantly, it takes into account differences in how climatic conditions are changing in individual countries and how species are responding. Wrens, for example, are benefitting from warmer winters in northern Europe but are experiencing declines in southern Europe where conditions were already warm and have become hotter and drier. As common species dominate ecosystems, even small changes in their abundance could have large knock-on effects on ecosystems. It is therefore important to monitor these changes and understand what drives them. This study’s application to policymakers is already apparent, as the CII has been adopted to assess progress towards biodiversity targets set by the United Nations Convention on Biological Diversity. This study was only possible due to the long-term and comprehensive data sets available for birds at the country level. The collaboration was facilitated by the European Bird Census Council (EBCC) which coordinates the Pan-European Common Bird Monitoring scheme, producing annual European bird indicators and supporting bird monitoring initiatives across Europe. If sufficient data existed, the approach could also be adapted for other species groups, such as butterflies or dragonflies and to other geographic regions.

Tit taxonomy is complex, with several species and subspecies reclassified many times since they were first formally described. This paper uses data collected during ringing to examine subspecies in Marsh Tits, with conservation implications for this declining species. The taxonomy of tits has been reviewed several times since they were first classified, with species such as Willow Tit and Marsh Tit, once considered one and the same, now classed as separate. Debate continues about subspecies, despite advances in molecular techniques and other tools. Marsh Tit, which has variation in coloration, wing and tail length across its range, is one species for which classification at this level remains unresolved. Marsh Tits in Britain underwent a 73% decline between 1966 and 2013. Two subspecies, Poecile palustris palustris and Poecile palustris dresseri, are designated in government biodiversity action plans, but it is not clear whether this distinction actually exists in British birds. BTO is part of a new collaborative study, led by the Centre for Ecology and Hydrology and published in the BTO journal Bird Study, which examines the question of Marsh Tit subspecies using measurements of wing and tail length collected during bird ringing at 14 sites across Europe, including eight in Britain. The results indicate that all British Marsh Tits in the study belonged to the subspecies dresseri, whereas those from elsewhere in Europe were from the palustris subspecies. This has implications for Marsh Tit conservation, as this species has declined in northern England and Scotland faster than in other regions. Previously it was thought the northern populations might be from the palustris subspecies, but evidence from this study suggests there is no ecological or taxonomic reason why birds from southern Britain could not be used for reintroductions further north. This therefore opens a possible new avenue for conservation of this declining species.