Puffins, already absurdly charismatic, have just been found to be even more special than they look: their beaks include fluorescent areas that glow blue under ultraviolet light. Although it seems likely the color is some sort of mating signal, no one really knows what the fluorescence is for or when it evolved, but it would certainly make them a hit at any nightclub or rave.
The discovery was made by accident. University of Salford ornithologist Jamie Dunning was procrastinating on his study on twites, a member of the finch family, and did what any bird scientist looking for a distraction from his main topic would do: investigate other birds.
“I’m the kind of guy that people send dead birds to,” Dunning told Newsweek, so his freezer was full of specimens. Dunning decided to pass them under an ultraviolet black light. He found barely detectable amounts of fluorescence on a few species, but the Puffin's beak lit up like a Christmas tree.
Crested auklets, puffin relatives from the northern Pacific, were reported last year to have beaks that fluoresce in a similar way, so the discovery did not totally surprise Dunning. Nevertheless, auklets are a much less famous species, with much more modest beaks, so Dunning's work is more likely to capture the popular imagination, particularly since puffins received a new bout of fame as the reason for The Last Jedi's porgs' existence.
Puffins, like many birds, can see frequencies the human eye cannot. Being even more dependent on excellent eyesight than humans, birds evolved a fourth cone for their eye, where primates have three and most other mammals, just two.
However, rather than shining in the UV, when exposed to ultraviolet light the beaks absorb the energy and re-emit it in the blue-violet part of the spectrum, where it is visible to human eyes as well. However, it only becomes noticeable to us when other lights are turned down so that the glow is not overpowered by other colors.
Dunning tweeted in response to questions that, although we see the beaks as glowing under UV, “We don't believe that this is interpreted as glowing to these birds – we can't guess what it might look like to them.”
Dunning is still working on a paper on his discovery, but announced it via Twitter in February. Aside from the Newsweek article, it didn't get much attention, but last week Dunning took things to the next level when he revealed the “sunglasses” he's designed to assist further research.
Puffin beaks' distinctive orange-red color is reserved for the mating season, and it's likely this fluorescence is also a form of sexual signaling. Dunning has also proposed an alternative theory; that it helps puffin chicks recognize their parents when they come bringing food.
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