Cattle egrets evolved on the vast savannas of East Africa where they followed herds of elephants, water buffalo and other herbivores, feasting on the insects that they stirred from the soil or that were attracted to the animals and their dung. Avoiding deserts and mountainous areas, these grassland herons eventually spread to coastal regions of Africa and thence to the Iberian Peninsula and southern Asia; it is likely that their dispersal was in response to human domestication of cattle, goats and camels, which became surrogates for the wild African herds.
By the late 1800s, cattle egrets (more closely related to herons than to other egrets) had spread to the Caribbean islands and then to northern South America. Their presence in both Florida and Australia was first documented in the early 1940s and a breeding population was established in Florida by 1953. In North America, they have since spread northward along the Atlantic Seaboard, westward along the Coastal Plain and northward across the Great Plains; they now breed in all but a handful of States and were introduced in Hawaii in 1959. Rather hardy, cattle egrets have been found in Newfoundland and southern Canada and visit both Tasmania and New Zealand during the warmer months; they have also colonized the British Isles over the past decade.
Cattle egrets are colonial nesters, sharing riparian woodland rookeries with herons and other wading birds. Non-breeding birds are nomadic and may turn up well beyond their documented range; of course, that range has expanded so rapidly that almost any land mass (short of Antarctica and other permanent ice sheets) is fair game for these adventurous and adaptable birds.
