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!
Look at those legs!
I didn’t know they had special bones to support their eyes. It is quite surprising but makes sense
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.
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.
I got so excited for the sclera that I missed your remark about the legs! That was another thing I loved about this photo.
Despite already being about the size of a fire hydrant, those legs are even longer than they first look in this photo. It is still squatted down. What looks like the shin is called the tarsus, which is the 3rd segment of leg birds have where our ankle would be.
Here you can see the 3 sections of the legs, the femur at the top, the fibula and tibiotarsus in the middle, and the tarsometatarsus (tarsus) going to the foot bones.
So our fish owl skeleton would be even taller yet, were its legs to be extended fully. This is just depicting it standing normally. Truly big birds by owl standards.
That is amazing! Looks like those legs might be longer than the wings if we’re not looking at the feathers. They really have such tiny torsos compared to the rest of them. A huge part of that must be devoted to the respiratory system.
I like fish owls. I wanted the Buffy to win last year so much :) There was this photo of one with a huge fish in the beak that I loved. Looking at the skeleton now it feels like that fish was not much smaller than the owl.
Respiration is right up there with musculature to allow them to fly. Got a great comment thread for you here about bird breathing. Birds don’t have a diaphragm to expand or compress the lungs like we do, so they have an entirely alien (to us mammals) process how they breathe!
As huge as that owl is, even the biggest of the big is still going to be under 10 pounds / 4.5 kg. They are mostly air, inside and out. Any extra mass just makes flying harder and raises energy requirements. Owl wings are generally large for their body size so they don’t have to flap as much, yet another thing that keeps sound down.
Fish owls are some really cool owls, and I’d love to see one and hear one! I hear they have very deep voices that travel a long way, supposedly to carry over water noise and such. Buffy is the cutest of them IMO, but Blakiston is quite huge, yet cuddly looking. I just took a look at my stuff for this year’s contest on Friday. No offence to White Faced Owl, but we need a strong competitor for it again this year! Snowy and Burrowing really need to secure those last few votes, they keep coming close but not quite enough, and I want to see some more wildcards like Buffy hit us with some surprises.
I’m glad to see you comment today! I feel I’ve seen you on my lurker list for a while now, and I always get excited when a new person gets excited enough to join in the conversation.
I’m mostly a lurker everywhere, in real life too… I like people but they make me nervous
Nothing wrong with that. You can keep enjoying things however you want! 🦉
