The Cattle Egret (Bubulcus ibis) is a species of heron (family Ardeidae) found in the tropics, subtropics and warm temperate zones. It is the only member of the monotypic genus Bubulcus, although some authorities regard its two subspecies as full species. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world. Despite superficial similarities in appearance, the Cattle Egret is more closely related to the genus Ardea, which comprises the great or typical herons and the Great Egret (A. alba), than to the majority of species termed egrets in the genus Egretta.
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.
Listen to the sound of Cattle Egret
Copyright remark: Most sounds derived from xeno-canto
|wingspan min.:||82||cm||wingspan max.:||95||cm|
|size min.:||45||cm||size max.:||52||cm|
|incubation min.:||22||days||incubation max.:||26||days|
|fledging min.:||28||days||fledging max.:||26||days|
Cattle egrets nest is large colonies with other wading birds. Pairs sometimes reuse old nests, or build new ones with live or dead vegetation. They will build in any place that can support a nest. Both sexes participate in nest-building: the female usually builds with materials brought by the male. They often steal sticks and other materials from neighbors’ unattended nests. Material is continuously added to the bulky nests during incubation and after hatching. Throughout mating, nesting, and incubation, a Greeting Ceremony is given whenever one mate returns to the nest to join the other. The Greeting Ceremony involves erection of the back plumes, and flattening of the crest feathers. Eggs are laid every 2 days, and the female does not become attentive to the nest until the last egg is laid. The eggs are light sky blue, turning lighter as time passes. Clutch size is usually 3-4 eggs, although extremes of 1 and 9 have been recorded. Incubation is carried out by both sexes, and lasts 24 days. During the first week, nestlings are easily overheated, and so the parents shade them from the sun beneath their wings. Both parents brood constantly for the first 10 days. The parents may accept chicks from other broods only if they are less than 14 days old. Begging for food becomes very aggressive in days 4-8, and the nestlings are very competative with one another. Siblicide is uncommon, though sibling aggression is strong. Most of the chicks’ growth is completed in the nest, but by 14-21 days, the chicks are capable of leaving the nest and climbing in vegetation, and are thus referred to as ‘branchers.’ At this stage, they remain nearby and continue to beg for food. At 45 days, they are independent, at 50 days they can make short flights, and at around 60 days, they fly to foraging areas.
Video Cattle Egret
Bubulcus ibis breeds mainly in Iberia but also patchily elsewhere in southern Europe,
which accounts for less than a quarter of its global breeding range. Its European
breeding population is relatively small (<150,000 pairs), but underwent a large increase between 1970-1990. The stronghold populations in Spain and Portugal continued to increase during 1990-2000, and populations were stable or increased elsewhere in its European range.
The Cattle Egret is a gregarious bird. The species nest in colonies (up to 10 birds to thousands) in trees or in bushes near lakes and ponds, sometimes with other herons. Searching food is collective, in small groups, they take advantage of disturbed insects by cattle. Cattle Egrets also flies in flocks, but unlike geese or other waders known for their strict aligning, they fly in uncoordinated formations. Most of the populaitons are resident, with some dispersion after the breeding season.