From The Raptor Center
Glimpse into the Glow.
When we recently admitted a young great horned owl, we broke out the black light to take a quick look at its feathers under ultra violet (UV) ight. Why? The pink glow can help us confirm the ow’s age. We know this is a bird in its first year of life because all of its wing flight feathers are glowing pink. The glow comes from proteins in new feathers called porphyrins. Under UV light, these porphyrins are fluorescent and visible to the human eye.
As feathers age, these pigments break down and the pink color subsides. The only time all of the feathers are new is when a bird gets its very first set of feathers. As these birds age, they only molt a few flight feathers each year, leading to uneven amounts of pink in older birds.
While we know that owls don’t have UV-sensitive cone cells in their eyes like diurnal birds, research shows that they can still detect UV light. There is no definitive answer as to the purpose behind the fluorescence of new feathers; however, it possibly conveys important information between owls in the wild.
It’s worth noting that the majority of animals can see in the ultraviolet light spectrum, meaning humans inability to do so is an exception and not the standard. How do you think UV vision would change the way we see our world?
Link has a video if you want to see more feathers glowing, but there’s no talking or text beyond what’s above here.
Not owl-specific, but interestingly penguins go through what’s called a “catastrophic molt” where they replace all their feathers in a short period of time (a few weeks to a month).
This is because they need their feathers to insulate them in the water. Typical bird molting, which lets most birds replace feathers without losing their ability to fly, would be like swimming with a leaky wetsuit for the penguins. This would force the penguins to burn too many calories just to stay warm. Instead they eat extra food leading up to the molt, then mostly stay on land and live off their fat reserves until the molt is finished.
If you made it this far, thanks for reading my bird nerd tangent lol
Very interesting, and it makes a ton of sense in their case!
I was wondering how they eat while having no feathers, but it seems they pig out for a few week before they molt. No wonder they load up, because they wouldn’t want to go out in public looking like this!
Yeah they definitely look worse for the wear during the molt. Also, having taken care of penguins before, they have waaay more feathers than you think they would.
Penguins look like a lot of fun, but that projectile poo makes me nervous! 😬
They look like they’d almost feel like a closed cell foam. Do their feathers feel oily or anything like that? I feel they’d have to have a water repellent coating from some thick preening oil.
I didn’t mind the projectile part, probably because they never got me. It is pretty acidic and eventually stains an area no matter how much you clean.
When dry the feathers feel smooth, but not really oily. If you’ve ever pet a duck it’s pretty similar.
I did have an African penguin almost knock me into the pool once. It was nesting season and he tried to take my radio’s antenna. While it was clipped on my belt and I was crouched down scrubbing the edge of the pool. Luckily I regained my balance and he found a real stick to take instead.
Huh, I wouldn’t have thought they felt like a duck. They look denser than that.
They seem like fun animals though. The one aquarium staff person showed me to use my hand to make shadows over the water and sometimes they’ll chase after it.
Watching them eat is pretty impressive too.