On the other hand, a few species that utilize their tail feathers as part of their sexual display have more than 12: for example, ptarmigan (16), prairie chicken and Ring-necked Pheasant (18), male peafow and Blue Grouse (20)."Īlthough the shape and distribution of pterylae vary among different families and orders of birds, eight major pterylae or feather tracts can generally be identified. Hummingbirds, swifts, most cuckoos, motmots, and toucans have 10, some rails and grebes have 8, and a few very small tropical passerine birds have 6. Rectrices - "Most birds have 12 rectrices (6 pair), although there are many exceptions.Alula feathers - "The number of alula feathers varies from only 2 quills in hummingbirds to as many as 5 or 6 in some cuckoos.Hummingbirds have the fewest secondaries (6), most passerines have 9 (rarely 10 or 11), while vulture species have 17 to 21, and albatrosses up to 32." Secondary remiges - "The number of secondary remiges is even more variable, ranging from 6 to 32, and is a result of variability in the length of the forearm (ulna).grebes, strorks, and flamingos have 12, herons, ducks, and gulls have 11, and several families of Old and New World passerines have 9." Primaries - "Most birds have 10 primaries, but.Prentice-Hall, Inc., Englewood Cliffs, NJ):
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