Cats are attracted to the calls made by male corncrake
Pet owners on the Western Isles have been asked by the RSPB to add bells to the collars of their cats to help protect one of Scotland's rarest birds.
Conservation officer Martin Scott said corncrake have been killed by cats after migrating to the islands to breed.
He said the bells could heighten the birds' chances of survival.
Good concentrations of corncrake are thought to exist on Lewis, North and South Uist, Tiree and Coll.
Mr Scott said: "Every year I see corncrakes that have been killed by domestic cats.
"It's a real shame, for a bird that has just flown in from Africa, but by taking a few simple measures it may be possible to reduce the death toll."
Corncrakes are most at risk during the night when male corncrakes start calling and attract the attentions of predators, the conservation officer said.
He added: "It would be great if cat owners in corncrake areas would keep their pets in during the hours of darkness.
"Another useful thing to do would be to add a bell to their collars. That heightens the chances of the corncrakes slipping away from the danger."
The species is a long-distance migratory species that winter in sub-Saharan Africa and come to the UK in summer to breed.
Corncrakes arrive in Scotland from Africa in mid-April
Their favoured habitat is tall grasses and herbs, particularly hay and silage meadows.
However, in the late 19th Century the mechanisation of farming led to crops being harvested quicker and corncrake population plummeted and became restricted to the Hebridean islands on the west coast of Scotland.
In 1993, the British population was estimated at just 480 males heard calling for mates.
But by 2003 this figure had almost doubled to 832 males.
Subsequent annual counts have shown that the population increase continued throughout the 2000s, and in 2007 the population in its Scottish strongholds hit a high of more than 1,270 calling males.
However, this number declined in 2008 by 8% to 1,140.