BTO Scotland publications

Collision, Displacement and Barrier - Effect Concept Note

Comparison of breeding bird assemblages in conifer plantations managed by continuous cover forestry and clearfelling

Modelling the abundance and distribution of marine birds accounting for uncertain species identification

Estimating seabird population size with uncertain species ID

Aerial surveys that capture high quality photos are increasingly being used to monitor bird populations, but these images are not always good enough to identify birds to species-level. A new study led by the BTO investigates how best to deal with this problem.

Raptors in Scotland – a methodology for developing trends and indicators

Published statistics on trends in raptor populations in Scotland currently use data from three national bird atlases, State of the UK Birds assessments, national BTO/JNCC/RSPB Breeding Bird Surveys (B

Modelling flight heights of marine birds to more accurately assess collision risk with offshore wind turbines

High flying birds at greater risk of collision with offshore wind turbines

New research by the BTO reveals that most seabirds fly near the sea surface, avoiding collision with wind turbines by flying under the blades. Those birds that fly higher above the sea are at greater risk of collision. Building offshore turbines higher above the sea surface, or installing fewer large turbines instead of several smaller turbines, could reduce the number of collisions.

Conservation management of moorland: a case study of the effectiveness of a combined suite of management prescriptions which aim to enhance breeding bird populations

Is moorland management for birds feasible without control of predation?

Reseach by the BTO, ADAS UK and the former Scottish Coal has examined the effectiveness of moorland management in south-west Scotland. British moorland can support important populations of breeding waders, gamebirds and birds of prey. Moorland and associated habitats are a result of management, in particular for sheep grazing and sport shooting of Red Grouse, but also prescriptions to maintain, restore or enhance particular components. While a suite of such prescriptions have been taken up quite widely, an ongoing decline of moorland birds is amongst the more marked results of the 2007-11 Bird Atlas.

Changes in breeding wader assemblages, vegetation and land use within machair environments over three decades

Changes in the Uists wader populations: the importance on agricultural practices and vegetation

The Uists in the Western Isles are home to a rare habitat known as “machair”, which supports exceptionally large breeding populations of waders, particularly Dunlin, Lapwing, Redshank, Ringed Plover, Oystercatcher and Snipe. A new study by the BTO and the James Hutton Institute investigated the role of changes in vegetation and agricultural practices using data spanning three decades.

Evidence for contrasting causes of population change in two closely related, sympatric breeding species the Whinchat Saxicola rubetra and Stonechat Saxicola torquata in Britain

Great skua (Stercorarius skua) movements at sea in relation to marine renewable energy developments

Scottish skuas in changing seas

Scotland has a large number of offshore sites where marine renewable developments (including wind, wave and tidal-stream installations) are proposed or under construction.The effect of these developments on marine ecosystems is not yet properly understood. Scotland is home to over 60% of the world’s breeding Great Skuas, and principal colonies are protected under the European Birds Directive. A new study led by the Environmental Research Institute and involving the BTO, has examined the potential effects of marine renewable developments on Great Skuas, using long-life GPS tags to reveal birds' movements throughout the breeding season and characterise their use of the marine environment.

Great Skua movements did not greatly overlap with areas of the sea where marine renewable developments are proposed. The largest overlap was with wave power installations, which are thought to pose a low risk to this species. However, the degree of overlap varied throughout the season and between colonies, with birds whose breeding attempts failed ranging over a larger area of sea than birds that were incubating or caring for chicks. Historical records of nest attendance also indicated that Great Skuas now travel further during the breeding season than in the past. Taken together, these findings show that assessing the potential impact of marine renewable developments on Great Skuas is complex. This long-lived species uses different parts of the marine environment at different times of the year, and might be flexible in choosing where to go depending on prevailing conditions. Tracking can help to assess the effect of planned marine renewable developments, but long term studies in conjunction with thorough monitoring are essential to fully understand the conservation implications for this and other seabird species.

Landscape transition through natural processes: implications for biodiversity of tree regeneration on moorland

The avoidance rates of collision between birds and offshore turbines

Understanding the risk of birds colliding with offshore wind turbines

Accurately estimating birds’ risk of collision with offshore wind turbines is a key part of the decision-making process for proposed renewable developments. However, the evidence base for quantifying the number of birds likely to avoid colliding with turbines is limited. Recent BTO-led work helping to fill this gap, improving the understanding of the impacts of offshore renewables on marine wildlife.

Effects on bird abundance and species richness of edge restructuring to include shrubs at the interface between conifer plantations and moorland

The importance of the United Kingdom for wintering gulls: population estimates and conservation requirements

A sample survey of the breeding birds at woodland expansion sites of the Scottish Forest Alliance in 2007

Effects on bird abundance and species richness of edge restructuring to include shrubs at the interface between conifer plantations and moorland

Diurnal and nocturnal ranging behaviour by moorland-breeding Short-eared Owls Asio flammeus in Scotland

The Biodiversity in Glasgow (BIG) Project

Ornithology Technical Report for the Proposed Dogger Bank Teesside A and B Offshore Wind Farm Projects

Raptors: a field guide for surveys and monitoring [3rd Edition]

Recent population declines in Afro-Palaearctic migratory birds: the influence of breeding and non-breeding seasons

Out of Africa: declines in migrants linked to UK breeding grounds

Recent research on declines in Afro-Palaearctic migrants has primarily focussed on conditions in these species’ wintering grounds. However, population changes could also be influenced by factors operating during breeding and migration, as a new study by the BTO and UEA shows. Scientists analysed data from the Breeding Bird Survey for 46 species and found that species breeding in Scotland are generally doing better than those in England. Several species were either declining in England but increasing in Scotland, or increasing in England at a slower rate than in Scotland.  These differences were especially stark in long-distance migrants, with species such as House Martin and Garden Warbler strongly increasing in Scotland only.

These results illustrate how population trends can be affected by interactions between breeding and wintering conditions, and the costs of making long migratory journeys.  While many migrants may be facing increasingly tough circumstances outside the UK, it is likely that these costs are being offset by better breeding conditions in Scotland than in England. Further exploration of such geographical variation is essential to properly understand the demographic processes underpinning population trends of these species, many of which are on the Birds of Conservation Concern Red List.