Returning Female Rufous Hummingbird
Auburn, Alabama
There are 10 primary flight feathers on the wings of Rufous and other hummingbird species.
They are numbered from 1-10 from the ending of the secondary flight feathers (1) outward to (10).
Loss of the primaries proceeds as follows:
P-10 first, then P-9, and on inward.
In this bird, P-1 through P-10 are new feathers
See interesting paper by Peng Chai in the J. of Exp. Biol., 200, 1527-1536 (1997)
http://www.jeb.biologists.org/content/200/10/1527.full.pdf
This paper describes mechanisms that may be in place to help hummingbirds compensate for the
loss of flight feathers during mots when the mechanism of lift force generation by flapping
wings is impared.