Speculum feathers
A male mallard. The speculum feathers comprise the patch of white-edged blue/black.
The speculum is a patch, often distinctly coloured, on the inner remiges of some birds.
Examples of the colour(s) of the speculum in a number of ducks are:
- Common Teal and Green-winged Teal: Iridescent green edged with buff.[1]
- Blue-winged Teal: Iridescent green.[2] The species' common name comes from the sky-blue wing coverts.
- Crested Duck and Bronze-winged Duck: Iridescent purple-bronze, edged white.[3]
- Pacific Black Duck: Iridescent green, edged light buff.[3]
- Mallard: Iridescent purple-blue with white edges.[1]
- American Black Duck: Iridescent violet bordered in black and may have a thin white trailing edge.[1]
- Northern Pintail: Iridescent green in male and brown in female, both are white on trailing edge.[2]
- Gadwall: Both sexes have white inner secondaries.[1]
- Yellow-billed Duck: Iridescent green or blue, bordered white.[4]
Bright wing speculums are also known from a number of other birds; among them are several parrots from the genus Amazona with red or orange speculums,[5] though in this case the colors are pigmentary and non-iridiscent.
References
- ↑ 1.0 1.1 1.2 1.3 Dunn, Jon L. and Alderfer, Jonathan (2006). National Geographic Guide to the Birds of North America. National Geographic Society. ISBN 1-4262-0072-2.
- ↑ 2.0 2.1 Bellrose, Frank C. and The Audubon Society (1983). The Audubon Society Master Guide to Birding. National Geographic Society. ISBN 1-4262-0072-2.
- ↑ 3.0 3.1 Madge, Steve; Burn, Hilary (1988). Waterfowl: an Identification Guide to the Ducks, Geese, and Swans of the World. Boston: Houghton Mifflin. ISBN 0-395-46727-6.
- ↑ Zimmerman, Dale A., Turner, Donald A., and Pearson, David J.; Illustrated by Zimmerman, Dale A., Willis, Ian and Pratt, H. Douglas (1999). Birds of Kenya and Northern Tanzania. Princeton University Press. ISBN 0-691-01022-6.
- ↑ Robert S. Ridgely and John A. Gwynne, Jr. (1989). Birds of Panama with Costa Rica, Nicaragua, and Honduras. Princeton University Press. ISBN 0-691-08529-3.