From Melvin Laureano Nature & Wildlife
A Great Gray Owl delicately testing the strength of a pine tree’s tip before settling-these large owls often perch high to scan and listen for prey below.
Mountainview County, AB
The world’s largest owl by overall length, the Great Grey is mostly air.
From an engineering perspective, if you take a hollow pipe and a solid bar of the same weight and length, the hollow one will be stiffer.
At first I thought that meant they’d likely need heavier bones to withstand the flying stress if they were solid. But solid bones aren’t bone all the way, I don’t think marrow doubles as load bearing material.
So perhaps the difference is all in respiratory capacity and weight distribution.