Which of the following does not describe a portion of a raptor wing?

The cere is a soft, fleshy area located at the base of a raptor's beak, above the upper mandible. It serves various purposes, such as housing the nares (nostrils) and functioning in reproductive signaling and species identification. Since the cere is anatomical but does not pertain to the structure of the wing itself, it does not describe a portion of a raptor wing.

In contrast, primary feathers, secondary feathers, and tertials are all specific types of feathers that play crucial roles in a raptor's flight mechanics. Primary feathers are the long feathers located at the wingtip, crucial for lift and thrust. Secondary feathers extend from the wing's main body, contributing to the aerodynamic shape and surface area. Tertials are the feathers located closest to the bird's body, and they assist in maintaining a smooth airflow over the wings during flight. Together, these feather categories are integral to the structure and function of a raptor’s wing.