Cattle Egret - Distribution and Habitat

Distribution and Habitat

The Cattle Egret has undergone one of the most rapid and wide reaching natural expansions of any bird species. It was originally native to parts of Southern Spain and Portugal, tropical and subtropical Africa and humid tropical and subtropical Asia. In the end of the 19th century it began expanding its range into southern Africa, first breeding in the Cape Province in 1908. Cattle Egrets were first sighted in the Americas on the boundary of Guiana and Suriname in 1877, having apparently flown across the Atlantic Ocean. It was not until the 1930s that the species is thought to have become established in that area.

The species first arrived in North America in 1941 (these early sightings were originally dismissed as escapees), bred in Florida in 1953, and spread rapidly, breeding for the first time in Canada in 1962. It is now commonly seen as far west as California. It was first recorded breeding in Cuba in 1957, in Costa Rica in 1958, and in Mexico in 1963, although it was probably established before that. In Europe the species had historically declined in Spain and Portugal, but in the latter part of the 20th century it expanded back through the Iberian Peninsula, and then began to colonise other parts of Europe; southern France in 1958, northern France in 1981 and Italy in 1985. Breeding in the United Kingdom was recorded for the first time in 2008 only a year after an influx seen in the previous year. In 2008 cattle egrets were also reported as having moved into Ireland for the first time.

In Australia the colonisation began in the 1940s, with the species establishing itself in the north and east of the continent. It began to regularly visit New Zealand in the 1960s. Since 1948 the Cattle Egret has been permanently resident in Israel. Prior to 1948 it was only a winter visitor.

The massive and rapid expansion of the Cattle Egret's range is due to its relationship with humans and their domesticated animals. Originally adapted to a commensal relationship with large browsing animals, it was easily able to switch to domesticated cattle and horses. As the keeping of livestock spread throughout the world, the Cattle Egret was able to occupy otherwise empty niches. Many populations of Cattle Egrets are highly migratory and dispersive, and this has helped the species' range expansion. The species has been seen as a vagrant in various sub-Antarctic islands, including South Georgia, Marion Island, the South Sandwich Islands and the South Orkney Islands. A small flock of eight birds was also seen in Fiji in 2008.

In addition to the natural expansion of its range, Cattle Egrets have been introduced into a few areas. The species was introduced to Hawaii in 1959, and to the Chagos Archipelago in 1955. Successful releases were also made in the Seychelles and Rodrigues, but attempts to introduce the species to Mauritius failed. Numerous birds were also released by Whipsnade Zoo in England, but the species was never established.

Although the Cattle Egret sometimes feeds in shallow water, unlike most herons it is typically found in fields and dry grassy habitats, reflecting its greater dietary reliance on terrestrial insects rather than aquatic prey.