Living Sanibel: White ibis
Although statewide the population of the white ibis is in decline, this unmistakable bird is found abundantly throughout Southwest Florida. Its long de-curved beak and its legs turn bright red when the white ibis is in breeding plumage. The distinctive black tips at the end of each wing when in flight make it an easy bird to identify. The juvenile is a mottled brown, similar in coloration to an adult limpkin. On the mainland you can sometimes find a similar species, the glossy ibis, which is the same size and shape but a dark blue-brown color similar to an oil slick. The immature glossy looks virtually identical to the immature white ibis.
The ibis was a particular favorite with early Florida homesteaders, producing an edible breast slightly larger than that of a popular game bird, the ruffed grouse-hence the nickname Chokoloskee chicken. Ibis were hunted throughout Florida well into the 1950s. Even today it is an easy bird to approach and still is hunted illegally in certain areas.
The white ibis feeds on fish, frogs, crabs, insects, and small reptiles. It mates for life and generally nests in large colonies with other wading birds. It is preyed upon by alligators and eagles, and its nesting sites are raided by raccoons and bobcats. Its predominant threat statewide is habitat destruction.
Like the cattle egret’s natural migration, the glossy ibis probably made its way to this side of the Atlantic from Western Africa via the trade winds or possibly caught up in hurricane winds. It was first seen along the northern edge of South America and has been expanding its range ever since. The glossy ibis is the most widespread ibis species in the world, with populations in Europe, Asia, Africa, Australia, South America, and North America. Similar in behavior to the cattle egret, the glossy ibis is rapidly acclimatizing to urban and suburban developments. This adaptable bird can often be found foraging along the grassy fringes of parking lots, ball fields, and agricultural areas. The North American population is still expanding, moving into coastal Georgia, South Carolina, and all the way north into Maine.
The brownish immature glossy ibis can easily be mistaken for an immature white ibis. Both birds achieve adult plumage within the first year, however, after which it is all but impossible to confuse the two.
The glossy ibis is slightly smaller than the white ibis. Both birds wield distinctive de-curved bills, which they use to ferret out insects, crayfish, grasshoppers, snakes, and grubs. They use these long, slender bills to probe deeply into soft, damp soil in search of prey. Unlike the white ibis, the glossy ibis is rarely found along the coastal beaches, preferring the near-coastal and mainland regions of Florida.
The glossy ibis nests in colonies of other herons and egrets. Its nests are subject to predation by snakes, raccoons, bobcats, opossums, and rats. The adult bird is taken by alligators, great horned owls, and bald eagles, but its reproductive abilities are such that the statewide population is still increasing. Its exceptionally long life span, up to 21 years, is also a factor in its ability to flourish.
This is an excerpt from The Living Gulf Coast – A Nature Guide to Southwest Florida by Charles Sobczak. The book is available at all the Island bookstores, Baileys, Jerry’s and your favorite online sites.