A blue-coloured gull found dead near Inverness has left experts searching for an explanation.
Wildlife enthusiast David Lynch came across the bird on the shore of the Beauly Firth near Clachnaharry on Sunday.
He shared a picture of the gull on Facebook along with an appeal for ideas on what may have caused its feathers to turn blue.
But so far no one has been able to find an explanation and even the RSPB have branded the death a “mystery”.
David, who is Highland coordinator for Eco Church Scotland, believes the bird may have come into contact with a poisonous chemical or been intentionally dyed by someone looking to track its movements.
He said: “I had just gone out for a walk and I was watching out for any birds on the path. That’s when I noticed that a gull had washed up on the shore and that its feathers appeared to be very blue.
“I wasn’t aware of any blue tinged gulls in the area so I took the picture and thought I would read up on it.
“I spoke to a friend who used to be a ranger in the Highlands and he told me about schemes in America where gulls are dyed to help mark their flight patterns.
“But the colour of the gull’s legs means it appears to be from this part of the world and as far as I’m aware, there is no one here carrying out that kind of tracking.”
David contacted the RSPB and Scottish SPCA to see if they could help him find out more about the type of bird and whether any other mysterious deaths had been reported in the area.
RSPB Scotland said they believe the bird to be a common gull and after examining David’s photographs, supported his theory that it may have come into contact with some kind of dye or chemical.
They told the BBC: “We think it’s a common gull. We’re not sure how it came to be that colour, which looks like a dye, and we’re unaware of any scheme involving dyeing.”
They added: “It’s a bit of a mystery.”