Scottish Warblers on the increase

Scottish warblers on the increase
– but concern for Kestrels
 
The latest Breeding Bird Survey report shows that two species of woodland warbler, Chiffchaff and Blackcap, are doing far better in Scotland than in the rest of the UK.
 
Whilst both birds have shown increases in the UK as a whole – 43% for Chiffchaff and 61% for Blackcap – their breeding populations have rocketed in Scotland. Between 1995 and 2008 the Chiffchaff, which sings its name, increased by 289%, while the Blackcap, a silver-grey warbler with a black cap in the male and a chestnut cap in the female, increased by 178% in Scotland. This is great news for both of these medium-distance migrants, which both winter in southern Europe and Africa. It is thought that the birds that breed in Scotland spend the winter in different areas to English breeders, and so may experience different conditions on their winter quarters. Chiffchaff and Blackcap are just two of 60 species monitored in Scotland by the Breeding Bird Survey (BBS), a partnership between the British Trust for Ornithology (BTO), the Joint Nature Conservation Committee (JNCC) and the Royal Society for the Protection of Birds (RSPB).
 
The latest survey results also reveal good news for the Whitethroat, a warbler that winters south of the Sahara. Whitethroats increased by 20% in the UK overall between 1995 and 2008, but in Scotland numbers increased by 86%. 
 
However, some birds have fared worse in Scotland than in the rest of the UK. The Kestrel is one of our most familiar birds of prey, often seen hovering over motorway verges on the look-out for small rodents. However, all is not well with this roadside hunter – the latest report reveals that Kestrels declined by -54% in Scotland between 1995 and 2008, and showed a further significant decline of -64% (of the 2008 figure) between 2008 and 2009 – a far steeper decline than in the rest of the UK. A previous decline in Kestrel numbers, between the 70s and 90s, had been linked to agricultural intensification on farmland habitats and the adverse effects this has had on populations of small mammals, but the reasons for more recent declines are not yet clear.
 
Kate Risely, BBS Organiser at the British Trust for Ornithology, said, “Volunteer surveyors put in an enormous effort to monitor Scotland’s breeding birds, surveying 328 1-km squares across the country. It is thanks to them that we are able to produce these trends for Scotland’s birds”. She added, “There are some areas of Scotland that would benefit from more surveyors – if you think that you have the birding skills to take part, please contact us at the BTO.”
 
Andrew Stevenson, a Scottish Natural Heritage Ornithological Advisor, added, “Whilst it is good to see some of our summer migrants doing well against the UK trend, the decline of Kestrel is very worrying. The reported decline in Scotland ties in with widespread evidence from the Scottish Raptor Study Group of declines across the country.  Quite why the decline in Scotland is more severe than the UK as a whole is as yet unknown and something we must investigate.”
 
RSPB Scotland's James Reynolds, said: “We are very worried that government spending cuts will affect the funding of the Breeding Birds Survey but also of conservation measures that would improve the fortunes of many declining species.”