Blakiston’s Fish Owl skeleton on display at the Shiretoko Rausu Visitor Center in Japan
Happy Halloween from the International Owl Center! We’re celebrating by sharing images of Blakiston’s Fish Owl skeletons (the largest owl in the world.)
Very interestingly, the sclerotic rings (eye bones) of Blakiston’s Fish Owls are proportionally much smaller than Snowy Owls and Great Horned Owls.
Blakiston’s Fish Owl skull on display at the Kushiroshitsugen Wildlife Center in Japan.
Snowy
Great Horned Owl
Check out more info I shared on the eye bones here!
Owls hold so many great secrets!
Owls and birds aren’t the only ones to have them, and they come in a few different styles, not all made of actual bone. Some of birds’ more reptilian relatives also have them, and a handful of fish as well.
Scleral Ring Wikipedia Entry
Examples of scleral rings in vertebrates. Common names in alphabetical order of images: great barracuda, cownose ray, mahi mahi, tarpon, wahoo, king mackerel, wild turkey, rock monitor lizard, eagle-owl, scarlet macaw, goose, crocodile monitor lizard, caiman lizard
Slightly more technical article here
Mososaur
Now that you mention it, I have seen something slightly similar in fish eyes, although those feel less like bone and more like cartilage.
Yup, different environments, eye shapes, and the activities the animals will experience have all lead to variations of the ring structures (or lack thereof).
A nice TIL for me is that in that collage, B is a ray, a cartilaginous fish, and it has a scleral ring, which is going to be made of cartilage, since they have no actual bone at all.