I was watching seagulls fighting at the beach. I noticed that during the kerfuffle many of the birds seemed to raise the feathers on their chests and backs. It reminded me of how a dog's hair will stand on end in a threatening situation.

However I couldn't tell if this was simply due to the wind or some other factor, or whether it is a genuine defensive behaviour. Do seagulls ruffle their feathers when threatened?

It got me thinking about the english idiom "to ruffle someone's feathers" and whether it has any basis in actual bird behaviour.



Not that I know of and from my reading. I think it's just the wind. Have noticed it too sometimes.