Some birds breeding in Yellowstone in Wyoming will overwinter in areas such as Texas and coastal Gulf of Mexico regions.

[5] Another theory was that a small population of glossy ibis dispersed to the Americas, which became isolated and evolved into a separate species.

[6] However, recent molecular phylogenetic studies show that the white-faced ibis may actually be paraphyletic.

[7] The white-faced ibis eats a variety of organisms, including many invertebrates such as insects, leeches, snails, crayfish and earthworms.

The white-faced ibis chooses to nest in the parts of a marsh with dense vegetation[8] such as bulrush, cattails, shrubs, and short trees.

[6] The pesticide DDT caused eggshells to be so thin and fragile that parent white-faced ibises crushed the eggs when they were incubating them.

[8][9] In order to correct these damages, DDT was banned in 1970 and various programs were created to better maintain and protect wetland nesting habitats.