What is the central ridge on a bird's sternum that serves as an attachment point for flight muscles called?

The central ridge on a bird's sternum that serves as an attachment point for flight muscles is called the keel. This structure is essential for birds, especially those that are strong fliers, as it provides a broad surface area for the attachment of the pectoral muscles, which are crucial for the wing movements necessary for flight. The keel allows birds to have the muscular power needed to flap their wings efficiently.

In contrast, the spine is part of the vertebral column and does not serve the purpose of muscle attachment for flight. The crest typically refers to a fleshy or feathered ridge found on some birds, such as those on their heads, and is unrelated to the sternum. The pelvis is a different part of the skeletal system that supports the hind limbs and is not connected to flight muscle attachment on the sternum. Thus, the keel specifically refers to the unique adaptation in birds that supports their flight capabilities.