Flight photo: Peter Pearsall
Wing photo: Kay Steele
Flocks of these long-legged, curved-bill waders are a regular sight in spring, summer, and autumn in the interior West. A drive past Harney County’s many flood-irrigated fields and wet meadows will undoubtably turn some up. Under the right light, the shimmering purple, green, and bronze plumage of breeding white-faced ibises is truly remarkable.
Ibises are colonial nesters, building nests on emergent vegetation such as bulrushes or cattails. At Malheur Refuge, ibis colonies form on Malheur Lake and Harney Lake and are often associated with other colony-nesting waterbirds such as Forster’s terns, Franklin’s gulls, black-crowned night herons, and blackbirds.
White-faced ibises began nesting at Malheur Refuge relatively recently. When the ornithologist Charles Bendire visited southeastern Oregon in the early 1870s to study breeding birds there, he didn’t encounter ibises. But soon after, in 1874, Harney County recorded its first white-faced ibis, and by the early 1900s the species was well established.
The breeding range of these ibises continues to change. Places like North Dakota and Alberta are seeing more and more white-faced ibises establish breeding colonies. This trend may be driven by climate and precipitation patterns, invasion and spread of emergent vegetation species such as narrowleaf cattail, changes in agricultural practices, habitat loss and range expansion in the southern and western portions of the species’ range, and increases in ibis populations in the Intermountain West.