Tuesday, January 26, 2010

America's Immigrant Stork

Natives of Central and South America, wood storks likely spread northward as the climate warmed following the Pleistocene Ice Age. Inhabiting the Coastal Plain of North America, from Texas to the Carolinas, they favor wooded swamps and marshlands, where they usually nest in large colonies.

Wood storks are easily identified by their large size and white plumage, fringed with black on their wings and tail; their head is gray and unfeathered and their long, thick bill has a slight downward curve. The latter feature led to their former title of "wood ibis" though they are, in fact, a member of the stork family. Moving about in small flocks, wood storks feed on fish and marine invertebrates in the shallows of coastal bays or hunt for frogs, lizards, small rodents and insects across freshwater wetlands.

Since they prefer to nest in the canopy of mangroves and cypress swamps, these large waders have been threatened by the logging of wetlands across the Coastal Plain. Nevertheless, they are still rather common in some areas; on Longboat Key, Florida, they often join ibis and egrets along golf course channels or stalk prey on the mudflats of Sarasota Bay during low tide. When soaring overhead, they may be mistaken for white pelicans but their classic silhouette, with extended necks and trailing legs, aids identification.