What we do
Flock of common scoters sleeping
Image: Graham Catley
The breeding population of common scoter in the British Isles has been in decline for many years; most recently, this population halved between 1995 and 2007. Reasons for these declines are poorly understood, but need to be reversed, or we risk losing common scoter as a British breeding species.
Fieldwork took place over three seasons, April-August 2009-11. Two comparable sets of 13 lochs, one regularly used by scoters, and one now rarely used, were compared in two study areas: the Flow Country and the West Highlands. At each loch, we measured the abundance of aquatic invertebrates, predators, fish, and physical factors like substrates and depths. Scoter foraging behaviour was quantified during standard watches of adults and broods.
This work is now in the writing up phase, and is informing our conservation action for this species.
Preferred scoter lakes are characterised by a greater abundance of large-bodied aquatic invertebrates - typical prey items of breeding scoters - and by larger areas of shallow water, which may make foraging easier for scoters.
Invertebrate abundance was higher where brown trout - which also feed on aquatic invertebrates - were rarer.
There were few strong links between scoter lake use and predator occurrence - but this could partly reflect poor detection of some predators by scoters. Introduced American mink were recorded at one important scoter breeding lake.
A group of Common Scoters (three females and one male) on their breeding grounds, in the Flow Country of northern Scotland
Loch sampling work under way in the Flow Country
Monitoring mammalian predators: inspecting a mammal monitoring tunnel (showing the clay plate and velcro strips)
Invertebrate sampling: lifting sediment grab
Invertebrate sampling: surface sweeping
A pair of common scoters, on breeding grounds at Forsinard RSPB reserve
Scoter female and ducklings at Forsinard Flows RSPB Reserve
Mark HancockSenior Conservation ScientistE-mail: email@example.com
Wildfowl and Wetlands Trust (www.wwt.org.uk)
The Conservation Volunteers (www.tcv.org.uk)
Scottish Natural Heritage (www.snh.gov.uk)
Environmental Research Institute (www.eri.ac.uk)