Friday, November 30, 2012

White-faced vs. Glossy Ibis

White-faced and Glossy ibis are difficult to tell apart. If you are close enough in the breeding season, note the white feathers lining the White-faced Ibis’s bare, red facial skin. The legs are pinkish-red. The first photograph shows a White-faced Ibis from Sand Lake National Wildlife Refuge near Aberdeen, South Dakota.
Glossy Ibis, on the other hand, do have white on the face, but the white lines do not meet behind the eye. Furthermore, this white color is not feathered, but a skin color. The facial skin is otherwise dark or bluish. If you are really close, eye color differs (red in Glossy, brown in White-faced). Finally the legs are dark on a Glossy Ibis. The lower photo was taken in Florida. In non-breeding plumage, the two species can be almost impossible to separate.
Some ornithologists consider the two ibis to be only racially distinct. The ibis interbreed in captivity. In the wild, in Louisiana and Alabama, where their ranges overlap, the two ibis nest in the same colonies but do not interbreed (Ryder and Manry 1964). Glossy Ibis are found along Eastern and northern Gulf coasts and in Florida; White-faced Ibis are western birds. Both species tend to wander, with Glossy and White-faced ibis occasionally seen well away from their expected ranges.

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