North American mink responsible for decline in island seabird numbers
The species colonised the western seaboard after escaping from fur farms in the 1960s.
American mink which escaped from fur farms in the west of Scotland in the 1960s are overfeeding on sea bird populations.
The North American mink have colonised the west coast over the last fifty years, causing major problems for native birdlife.
Breeding populations of nationally rare sea birds - like terns and common gull - on west coast islands between Mallaig and West Loch Tarbert have suffered.
Dr Clive Craik, of the Scottish Marine Institute, has spent the last 22 years studying populations of breeding seabirds on 155 islands.
Once a mink accesses breeding colonies it can go on "killing sprees, wiping out a whole season's worth of chicks or eggs in a single night", he said.
Surviving birds will move away from the area rather than tolerate another attack, said Dr Craik, of the Scottish Marine Institute.
In 2010, studies showed that 76 of the islands had lost their breeding seabirds and mink had all but eradicated ground-nesting birds.
Results for 2011 show that seabirds bred successfully on 21 out of 28 islands which had a programme of mink-trapping.
Dr Craik said that discarded fishing gear is also responsible for significant deaths among seabird populations.