Great White Egret (Ardea alba) R&T 22-09-2020
spanwidth min.: 145 cm
spanwidth max.: 170 cm
size min.: 85 cm
size max.: 100 cm
incubation min.: 25 days
incubation max.: 26 days
fledging min.: 38 days
fledging max.: 46 days
eggs min.: 2
eggs max.: 6
The great egret is a large bird with white plumage, a long thin body, a yellow bill, and legs and feet that are glossy black. The sexes are similar in size, males being slightly heavier. Adults average 81 cm in length with a 140 cm wingspan and weigh between 2 and 2.5 kg. This heron is larger than any other except for the great blue heron. In flight, the great egret holds its neck in a more open S than do other white herons.
The preferred habitat of great egrets is along freshwater and saltwater marshes, ponds, streams, lakes, wooded swamps, mud flats, and urban environments
This cosmopolitan species inhabits large swamps, swamp forests, estuaries and coastal marshes in temperate and tropical regions. In Europe it declined strongly since the middle of last century, and it is currently restricted to the central and south-eastern parts of the continent. European birds winter mainly in northern Africa and around the eastern Mediterranean, but an increasing number of individuals winter in Central Europe and the Netherlands. This bird seems to be very sensitive to the conditions of its habitats, and its populations fluctuate strongly. Its Central and Western European populations are increasing since about 1965, and a breeding colony (1-3 pairs) became established in the Netherlands in 1991. The Greek populations are still decreasing, however. The total population of the European Union remains marginal thus compared to the total European population which can be estimated at 12500-16000 breeding pairs
Great egrets are standing motionless in the water waiting for their prey. Their diet primarily consists of aquatic invertebrates and fish. But, they are also known to eat reptiles, amphibians and small mammals. Great egrets forage very similarly to great blue herons; walking slowly through shallow water and snapping up prey as it crosses their path. Young are usually fed frogs, crayfish, and small fish that are regurgitated into their mouths by a parent
This species has a large range, with an estimated global Extent of Occurrence of 10,000,000 km². It has a large global population estimated to be 550,000-1,900,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]
Great Egrets usually nest near water, in trees, shrubs, or thickets. They probably first breed at 2-3 years of age. Although isolated pairs are sometimes seen, colonies--often multi-species--are the norm. In multi-species colonies, the Great Egrets tend to nest higher than other species. The male selects the nest area where he displays to attract the female. Both sexes build the stick nest, and both help incubate the 3-4 eggs for 23-26 days. Both parents feed the young by regurgitation. At the age of three weeks, the young may begin to climb about the nest, but do not fledge until 6-7 weeks.
Extensive post-breeding dispersal. Populations of Palearctic and Nearctic partially migratory with some dispersive movements; tropical populations sedentary. E Asian birds migrate to SE Asia and Philippines, whereas birds from rest of Palearctic move to Mediterranean, Middle East, Persian Gulf and Pakistan. Birds of E USA winter S along coast to Bahamas and West Indies; W birds move S towards California, Mexico and C America; populations of Mississippi Basin move S to Gulf coast. Australian populations generally dispersive, although some regular seasonal movements occur, which might be migratory; sometimes irruptive, e.g. moving from interior to coast during droughts; occasionally to New Zealand; New Zealand population. Vagrant to islands of subantarctic, Seychelles, Canary Is, N and C Europe; several recent records of race modesta in Europe.