Though cattle egrets were first observed in North America in the 1940s and were breeding here by the early 1950s (see Global Egret). they are not widespread in the U.S. Permanent populations are found in Florida, along the Gulf Coast and in California while summer residents have spread along corridors where riverine marshlands, open country and cattle have invited their presence.
Summer populations of cattle egrets are found along the Atlantic Seaboard (as far north as New England), up through the lower Mississippi Valley (where the floodplain is broad) and westward along the corridors of the Rio Grande, Red and Arkansas Rivers. While they inhabit the Bootheel region of Missouri, I have never seen them along the Missouri River and, though I have seen large flocks in Oklahoma and southern Kansas, I have never encountered cattle egrets on my many journeys along Interstate 70 (between Missouri and Colorado). Then again, small flocks may be found near reservoirs in eastern Colorado during the summer months, presumably having migrated north from Mexico or westward along the Arkansas River; some California residents also move up the Pacific Coast during the warmer months.
In late summer and early autumn, however, cattle egrets are highly mobile and may turn up along almost any North American coast or river corridor. As their population continues to expand, they are likely to become permanent residents across the southern States and summer residents in all other areas that offer the basic requirements mentioned above; by then, only mountainous regions and desert landscapes will be excluded from their North American domain.
