Common Scoter
Surfbirds News: RSPB Archives
Although factors driving the reduction in the breeding population are still unclear and more research is needed to determine the precise causes, there are several possibilities.
The highest declines have been in the south and west of their British range; they have been lost completely from Loch Lomond and in Northern Ireland, so it is possible that changes to the climate could be pushing the birds further north.
Plantations and inappropriately sited forestry in the Flow Country of North Scotland have also led to changes in the water chemistry of some freshwater loch systems, causing invertebrate populations to shift. This could be restricting food availability and making it more difficult for them to thrive in their historical territories.
Common Scoter (female) © Josh Jones, from the Surfbirds galleries
Elsewhere predatory species such as pike have been introduced in some of the lochs where scoters used to breed and this could be responsible for higher chick mortality restricting their breeding success. However, some scientists believe that pike might actually help common scoters, predating smaller fish which compete with the ducks and their offspring for the invertebrates in the water systems.
Mark Eaton, research biologist with RSPB who led the survey, said: 'A decline of this nature highlights precisely the gravity of the situation facing common scoters in the UK right now. For this to have occurred in such a short time period is rare and of great concern. However, the news isn't all bad. We have a great track record of turning round the fortunes of species that have experienced such precipitous declines, such as the corncrake and the red kite. We really need to get out and conduct more research over the coming years to firmly establish the causal factors that have driven this reduction in the breeding population so we can stop it. We can then put together conservation measures and management schemes that will hopefully ensure that the common scoter can flourish in UK once more.'
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