The bird's mandible is likely to continue to grow
A blue tit with an unusually long bill has been spotted at a RSPB nature reserve in Lochwinnoch, Renfrewshire.
The bird, which has an overgrown upper-bill, has been visiting the reserve's feeders for several weeks.
Overgrown bills are uncommon in wild birds and would normally prevent them from feeding.
The blue tit has, so far, shown no signs of difficulty but experts believe the deformity will grow and affect its ability to feed and preen.
Kirsi Peck, from the RSPB's wildlife inquiries team, said: "A bird's beak is rather like a human fingernail and grows at a slow rate throughout its life.
"Normally, the two sections work against each other while the bird feeds ensuring that they stay the correct shape and size.
"But in this case, it looks like something has happened to the upper mandible causing it to grow excessively.
"It's likely to continue to grow, and unfortunately, it will eventually affect the blue tit's ability to feed and preen. It's really quite amazing that it's doing so well at the moment."