And it's real fluorescence, Dunning emphasizes: something about those parts of the puffin bill is allowing that UV light to be absorbed and re-emitted as a bright glowing light.
It's just not clear yet what that something is, he said [...]
Unlike humans, birds have always known about the extra colours in the puffin bill. That's because they can see a whole other dimension of hues, said Dunning [...]
Birds probably don't see those ridges all lit up like we do, said Dunning.
"It's hard to say what it would look like [to them], we can't comprehend that colour space.
"But almost certainly it's attractive to the birds. They must be able to see it — that's the only reason it would exist." [...]
So far, the fluorescence has only been seen in dead puffins in Dunning's lab.
That means he has to test out the UV light on some live puffins to ensure the beak brightening isn't happening because of decomposition [...]
He'll be publishing a paper about puffin fluorescence with colleagues at the University of New Brunswick, and expects more research will follow.