The cattle egret is an opportunistic feeder, with a diet that consists mainly of a variety of insects, spiders, frogs and worms. It follows large grazers such as plains zebras (Equus quagga) and water buffalos (Bubalus bubalis) to find its meals more quickly (7); when a grazer pulls up grass to eat, it also exposes organisms in the soil below. These are easy pickings for the egret and as the bird does not hinder the grazer, the relationship is a successful one. The cattle egret can also forage for food by itself without aid from grazers but the process is much slower and requires more energy (3).
Breeding generally takes place near water sources and in colonies, and starts with males competing with each other using animated sexual displays. If a male is successful in finding a mate, the pair will produce one brood for the season, laying between one and five eggs in a nest made from sticks that the male has collected and the female has arranged. The males will find a new mate each season (3). Studies have shown that there is intense sibling rivalry over food and more aggressive chicks tend to prevail, sometimes even resulting in the weakest chick dying of starvation (8).
This species of egret is described as a ‘partially’ migratory bird (6); whether a group will migrate depends on the climate and the food availability in the area. In the northern hemisphere the cattle egret tends to migrate from cooler to warmer climates in the winter, and return in the summer when temperatures increase. In Australasia, the cattle egret travels from mainland Australia to New Zealand and Tasmania between February and April, and remains there until October or November (9).