The UK Cormorant population has increased in size and range in recent decades, with more birds breeding and wintering inland, leading to potential conflicts with fisheries. Control measures have been introduced in response to this, with licences issued to kill up to 2,000 birds annually since the mid-2000s. New research by the BTO has examined whether this control has been associated with changes in Cormorant numbers on Wetland Bird Survey (WeBS) sites, especially on Special Protection Areas (SPAs) designated to protect particular species under the European Birds Directive. Although there has been a decrease in Cormorant population growth nationally since the mid-2000s, there was no evidence that killing Cormorants one winter affected numbers at local sites the following winter. However, some results indicated that Cormorant population growth was associated with higher intensity control (although this was not seen on SPAs). One explanation for this positive relationship could be that disturbance caused by control increases Cormorant dispersal, leading to apparent population growth at the site level. Alternatively, the results may reflect the fact that control measures are often reactive, with licenses granted in response to local increases in Cormorant numbers. Due to the potential for increased Cormorant movements following control, both at larger scales and between unmonitored and monitored sites, these findings do not provide evidence as to whether control has influenced the national population trend. Further work is needed to better monitor Cormorants outside WeBS sites and to research their population dynamics, movements and behaviour. The key questions of whether Cormorant control has the desired effect of reducing predation at fisheries, and how cost effective it is compared to other measures, remain to be answered.

There has been plenty of work on the effect that climate change might have on the range of particular bird species; for example, Dartford Warbler is predicted to extend its range north with an increase in temperature. However, for the first time, scientists at the British Trust for Ornithology have looked at what effect climate change might have on the distribution and abundance on particular species. Four species were chosen; two with a southerly distribution, Nuthatch and Green Woodpecker, and two with a more northerly distribution, Meadow Pipit and Curlew. Future climate change was projected to result in population declines and range contractions northwards for both northerly distributed species (Figs 1 & 2). Declines for Eurasian Curlew were projected to be particularly severe, with national abundance under a high climate change scenario projected to be 34% lower in 2050 than the 1997 baseline, and 66% lower by 2080, a statistically significant drop. Modelled abundance in 1997 and 2080 under a high emissions scenario for Eurasian curlew In contrast, the two southerly species were projected to have population increases as a result of climate change. Green Woodpecker populations may increase substantially by 2050 and populations of Nuthatch to a lesser degree. The analytical methods used provide an important framework to make projections of impacts of climate change on species abundance, rather than simply projected range changes. Given the recent classification of Eurasian Curlew as globally near-threatened, these projections of continued population decline in Great Britain, where a significant proportion of the global population is held, and where declines are already occurring are of particular concern and highlight the likely long-term vulnerability of this species. The long-term protection and management of upland habitats in the English Pennines, Southern Uplands, central Highlands and Scottish islands, where the species presently occurs and is projected to remain at highest density in future, should therefore remain a conservation priority, highlighting the importance of this work.