A cattle egret is a small, white heron that follows herds of cattle to feast on insects the animals attract. The birds originated in Africa, where they enjoyed a symbiotic relationship with wildebeests and other large grazers. Today, cattle egrets can be found around the world, from Maine to Australia to Brazil.
Also known as the buff-backed heron, cattle egrets have yellow bills and orange or black legs and feature brilliant white plumage. They are stocky, short-necked birds. Fully-grown cattle egrets are usually about 20 inches (51 cm) in length. Immature birds have darker legs and bills.
Cattle egrets let large grazing animals do the work of finding food. Cattle and wildebeests kick up dust, disturbing insects; the animals also attract flies. The birds like to perch on the backs of grazing animals. Dietary staples include grasshoppers, flies, spiders and crickets. They might also eat fish, frogs and mealworms.
The first recorded appearance of a cattle egret in the Western hemisphere was in 1877, where a bird was found in the northeastern region of South America. By 1953, the bird was seen nesting in the US. Due to the cattle egret's adaptability and its ingenious approach to finding food, the birds have spread rapidly in North America. Cattle egrets nest in nearly all 50 states and have been recorded from Newfoundland to Alaska.
As they are quite sociable, cattle egrets commonly live in groups of several hundred. A cattle egret colony might nest in a close-knit group of trees, traveling in a flock to the foraging areas each morning. Cattle egrets prefer marshes, but also thrive in fields, wetlands, pastures and areas where livestock are kept.
During breeding season, the male cattle egret develops buff-colored feathers on its head, chest and back. The egrets mark out their territory and choose a female. Female cattle egrets lay between two and six eggs. The mother injects more male hormones into the first-born egrets, which can be quite aggressive and even kill their brothers and sisters. Male and female egrets share the parenting duties.
Cattle egrets are highly adaptable birds. An example of this adaptability can be seen in modern life. Cattle egrets have learned to follow farm tractors: like cattle, these tractors disturb all manner of tasty insects. Colonies of cattle egrets have also been seen near airport runways—the birds feast on clouds of insects kicked up by landing planes. A cattle egret is also adept at sensing smoke from nearby fires, where it can feast on insects fleeing the flames.
The adaptability of cattle egrets also makes them fierce competitors for resources. In Hawaii, cattle egrets have pushed out other wetland birds. The egrets compete for food and prime nesting space and have been known to attack young birds of other species.