RSPB Scotland has urged people to discard unwanted plastic bags carefully after a rare bird was photographed with one caught in its beak.
The birds are on the RSPB's amber list after a recent decline in numbers.
Jamie Boyle, site manager of the RSPB's Uist reserves, said plastic bags can kill birds if they eat, or become entangled, in one.
He said: "We urge people to take great care in the way they dispose of plastic bags or, indeed, any other rubbish, particularly balloons and Chinese lanterns.
"They pose a direct threat to our wildlife and it is depressing to think that plastic bags are even reaching remote lochans in a place like North Uist."
Mr Boyle added: "Marine birds such as red-throated divers are particularly at risk both at sea and on their breeding grounds where they can mistake the bags for fish or mistakenly use it for nesting material."