Ecology and conservation of breeding common scoters

This project aims to find out how we can reverse the population decline of breeding common scoters.

Common Scoter Melanitta nigra, male and female swimming, Forsinard Flows RSPB reserve, Sutherland, Scotland


Common scoters were once widespread breeding birds across upland lakes in Britain and Ireland, with several hundred breeding pairs. Numbers have declined sharply in recent years, down to just a few tens of pairs. This project is building a detailed picture of the ecology of this species, with a view to developing conservation measures. 
We found scoters strongly prefer lakes with abundant shallow water and large freshwater invertebrates, like caddisflies and mayflies - these are typical prey items of scoters at their breeding lakes. We also found scoter foraging was strongly concentrated in shallow water.
We are now testing methods of improving habitat quality for scoters. At RSPB Forsinard Reserve, we are testing whether increases in brown trout angling, at lakes which have recently had little fishing, will lead to an increase in insect abundance.


  • To determine the factors correlated with lake use by breeding common scoters in Britain and interpret these in relation to options for scoter conservation.
  • To determine whether the abundance of large invertebrates (which are typical scoter prey in freshwaters) was correlated with fish abundance and/or water quality.
  • To test whether reductions in trout abundance lead to increased availability of large freshwater invertebrates and hence improved habitat quality for breeding scoters and other waterbirds.


Key Dates

  • 2009-2011: a three year study of common scoter breeding ecology was carried out, at 26 lakes holding about half of Britain's breeding scoters.
  • 2013-2018: a six year trial management project was established at Forsinard RSPB reserve, testing the effect of trout management by angling, on invertebrate abundance and lake use by scoters.

Planned Work

Fieldwork for the management trial will be completed in autumn 2018. The samples and data will then be analysed and interpreted. The results will be used to inform scoter conservation measures.



Coast on a stormy day

Dr Mark Hancock

Senior Conservation Scientist, Conservation Science

Further reading

Tagged with: Country: Scotland Habitat: Upland Habitat: Wetland Species: Common scoter Species: Dunlin Species: Greenshank Species: Wigeon Species: Wood sandpiper Project status: Ongoing Project classification: Ongoing Project types: Research