An incredible photo of a puffin reveals that the birds' beaks actually have a fluorescent quality to them. Evidently, a part of their beaks glow bright blue when exposed to ultraviolet (UV) light.
Bright Blue Beak
Last February, ornithologist Jamie Dunning tweeted a photo of a puffin whose beak was glowing a bright blue as it was exposed to UV light. Evidently, the discovery of the fluorescent beak is actually pretty accidental as Dunning often works with twites and not puffins, and he just exposed the puffin's body to UV light because fluorescence was also observed by other researchers on auklets, another type of sea bird.
'[birds have] additional color cones in their retina that are sensitive to ultraviolet range.' I exposed some of my specimens to UV light.
The Puffins bill was pretty cool, I wonder if it's related to signalling? #Ornithology pic.twitter.com/eZTbrmi0y5 — Jamie (@JamieDunning) February 8, 2018
There are still uncertainties regarding the mechanisms as to why the birds' beaks glow. but at the time, Dunning speculated that it could perhaps be a signaling mechanism, especially since birds can see a wider range of colors compared to humans. This means that there is a possibility that even though the fluorescence is not visible to humans, it could be normally visible to other birds.
As to its purposes for the life of the puffin, Dunning surmises that it could perhaps be a mating signal since puffin beaks are known to lose the bright orange color when the mating season is over.
Because the original photo of the fluorescent beak was of a dead puffin, Dunning is working on a "sunglasses" design for live puffin to wear so that they can test beak fluorescence on live puffins. This way, they can expose them to UV light without the possibility of harming the birds' eyes.
Atlantic puffins are sea birds that prefer the cold waters off the coast of North America. They are known for their bright orange beaks, small body, and smooth plumage. These birds forage for food such as small fish, crustaceans, mollusks, and marine worms by diving underwater.
As parents, puffin pairs work together in creating the nest, incubating the eggs, and feeding their nestlings until they are big enough to fly away about 44 days after hatching. Often, puffins mate with the same partner every year.
The population of Atlantic puffins began to decline in the 19th century as a result of the over-harvesting of both the eggs and adults, and the decline continued on to the 20th century because of the introduction of predatory animals in their habitats. Although the 1970s re-introduction of puffins in nesting islands has been largely successful, their numbers are still in decline because of the continuous rise in temperature.