Casque refers to which feature on a bird's head?

Casque refers to which feature on a bird's head?

• A. A nest built by birds.
• B. A place where birds rest or sit.
• C. A helmet-like structure on the head of some birds, often used for display or protection.
• D. A type of wing feather.

Answer: (C)

A casque is a helmet-like structure on the head of some birds. It’s a hard bump or crest on top of the skull, made of bone and/or keratin, and it can vary in size and shape between species. In cassowaries, the casque helps make the bird look larger to rivals and may provide some protection as it moves through dense vegetation; in other species it can play a role in display or signaling fitness to mates. This feature is not a nest, not a place to rest, and not a wing feather.