(noun) The leading (front) edge of a bird's wing between the shoulder and the wrist. When extended, marks on this part of the wing can be useful for identification, particularly for birds of prey. The patagium is thin and flexible, giving birds better aerodynamic flight and allowing them a high degree of control over their maneuverability.
To identify a bird by marks on its patagium – called patagial marks – note the color, width and length of any markings and compare them to other parts of the wing, including marks on the wrist, primary feathers, trailing edge and underwing coverts.
Some bird species, particularly large birds such as California condors, will be tagged with patagial tags that are clipped to the patagium without harming the bird or interfering with its flight. These tags are often brightly colored and can be read easily on a flying bird.
Photo – Red-Tailed Hawk © Keith
PAH-TAY-gee-um or PUH-TAY-gee-um