Plumage Studies Roxie Laybourn Smithsonian Institution Feather identification

Plumage Studies • Roxie Laybourn, Smithsonian Institution • Feather identification expert – Smuggling – Aviation accidents – Rare bird identification • Museum of Natural History at Smithsonian Inst. has over 650, 000 specimens

Plumage I: Growth • Birds have a series of plumages • Growth & maturation – Natal down to adult plumage Psilopaedic typical on altricial birds Ptilopaedic on precocial birds First fragile feathers only 1 -2 weeks May have second set of down, most have juvenal plumage, including wing and tail feathers • Parts of juvenal plumage replaced with either immature or adult plumage • •

Juvenal & Adult Robins

Gulls • Rule One still applies: some gulls are unidentifiable – From review of the book: Gulls of North America, Europe, and Asia Immature Herring gull Immature Western gull

Slaty-backed Gull • Early juvenal to adult plumages (3 -4 years)

Plumage II: Seasonal • Two primary purposes – Migration preparation – Mating and breeding preparation • Most adults molt after breeding – May keep plumage entire year • Can still change appearance as feather tips wear off - meadowlark – May partially replace before breeding next year

Yellow rumped warbler • From left top – Juvenal – Winter – Spring – Summer breeding

Molt • Plumage at first molt postbreeding is “basic” • Breeding plumages are “alternate” Female Male molting Male breeding plumage

Molt purposes • Replace wornout feathers • Be cryptic in non-breeding season, more sexually attractive in breeding season – ecological tradeoff of reproduction pressure vs. predation pressure • Eclipse or cryptic plumage for many females especially at nest; juveniles, non-breeding males • Infestation of parasites can destroy plumage rapidly • Some species do several partial molts annually

Molt Patterns all primaries done, secondaries growing 1 st primary starting to grow • Most birds molt sequentially, e. g. innermost primary outward • Some species, e. g. many ducks, molt all flight feathers at once Female American Goldfinches www. westol. com/~banding/Pictorial_Highlights_100405. htm

‘A Bird of Prey’. Engraving from Punch 14 th May 1892

Spectacular feathers Sulphur crested cockatoo hoopoe Scissor-tailed flycatcher Quetzal