Does Flightless Birds Have Bones?

Flightless birds do have hollow bones. Ostriches and emus have hollow femurs. It's thought that the air sac system that extends into their upper legs is used to reduce their body heat by panting. This bone specialization isn't found only in birds.

Do flightless birds have heavy bones?

Flightless bird's bones are more dense and heavier than flighted birds. With the exception of penguins, which have adapted to “flying” through the water, most flightless birds lack a keeled sternum for flight muscle attachment.

Which flightless birds have heavy solid bones?

Ratites have heavy, solid bones, while flying birds have lightweight, hollow ones. Several ratites, such as ostriches, rheas, emus, and cassowaries, are the largest living birds. The kiwis of New Zealand, however, are about the size of chickens. These flightless birds are the oldest living birds.