tail feather

A tail is a prolongation of the backbone beyond the trunk of an animal's body. In zoology, it can also refer to any slender projection resembling such a structure. Tails serve various functions across different animal groups, including locomotion, balance, defense, social signals, and even as a prehensile limb.12

In birds, most of the tail vertebrae are fused into a pygostyle, which supports the tail feathers that are crucial for flight maneuverability. These tail feathers, known as rectrices, are a type of contour feather made of keratin. The number of tail feathers can vary among species, typically ranging from 6 to 16.1345