«

»

Sep 25 2011

Print this Post

Black Heron (Egretta ardesiaca)

Black Heron

[order] CICONIIFORMES | [family] Ardeidae | [latin] Egretta ardesiaca | [authority] Wagler, 1827 | [UK] Black Heron | [FR] Aigrette ardoisee | [DE] Glockenreiher | [ES] Garceta Azabache | [NL] Zwarte Reiger

Subspecies

Genus Species subspecies Region Range
Egretta ardesiaca AF widespread

Genus

Egretta is a genus of medium-sized herons, mostly breeding in warmer climates. Representatives of this family are found in most of the world, and the Little Egret, as well as being widespread throughout much of the Old World, has now started to colonise the Americas. Little Egret Egretta garzetta in Kolleru, Andhra Pradesh, India.These are typical egrets in shape, long-necked and long-legged. There are few plumage features in common, although several have plumes in breeding plumage; a number of species are either white in all plumages, have a white morph (e.g. Reddish Egret), or have a white juvenile plumage (Little Blue Heron). The breeding habitat of Egretta herons is marshy wetlands in warm countries. They nest in colonies, often with other wading birds, usually on platforms of sticks in trees or shrubs.

Physical charateristics

Medium-sized heron with all over black plumage, feathers exhibit a glossy grey / slate sheen. The crown has a small crest of feathers. The bill is narrow and pointed, and black in colour. The legs and feet are yellow, as are the eyes.


wingspan min.: 90 cm wingspan max.: 95 cm
size min.: 43 cm size max.: 66 cm
incubation min.: 18 days incubation max.: 30 days
fledging min.: 0 days fledging max.: 0 days
broods: 1   eggs min.: 2  
      eggs max.: 4  

Range

Africa : widespread

Habitat

The species mainly inhabits lowlands, but occurs up to 1,500 m in the High Plateau Region of Madagascar. It shows a preference for shallow, perennial3 freshwater habitats1 such as shallow lakesides, dams, ponds, flood-plains, rice-paddies, marshes, swamps, seasonally flooded grasslands and the edges of rivers. It can also found on alkaline lakes and in estuarine waters including mangroves, tidal mudflats and tidal creeks, although when in such habitats it remains near freshwater inlets.

Reproduction

Breeding occurs during the rains and flooding periods, and the male begins to collect nest materials while simultaneously trying to attract a female. Nests are usually scattered in colonies mixed with other herons, egrets or darters. Both sexes’ yellow-orange feet turn bright red during courtship.The male stretches on his perch, pointing his head and neck to the sky, inviting the female to take a closer look. After mating, the pair builds a nest of sticks and rocks in trees up to 15′ above ground, or in bushes or reed beds near or over water. Both sexes incubate for the 2-4 eggs for 18-30 days.The helpless and blind chicks are covered with a dark-gray down and hatch at different intervals over a one-week period; the adults feed them regurgitated food. Because of the hatching intervals, there is a big difference in the chicks’ size, and the largest chick often gets more food; some late-hatching chicks do not survive. Juveniles resemble adults but have duller plumage and reach maturity in 1-2 years.

Feeding habits

The black heron feeds mainly on fish and employs a unique feeding technique ? it lures prey to the surface of the water by forming a canopy with its wings. The black heron walks about slowly, intermittently spreading its wings over its head like an umbrella, maintaining this pose for 2-3 seconds. The canopy reduces glare and forms shade ? this attracts fish, its favorite prey. The black heron spears a fish with its long, pointy bill, and swallows it whole, usually head first, to avoid the fish’s spiny fins. This bird also feeds on crustaceans and aquatic insects that it stirs up by raking its feet along the muddy bottom. The black heron feeds during the day or at dusk, and then moves off to nighttime communal roosts with other herons, egrets and darters.

Video Black Heron

httpv://www.youtube.com/watch?v=KFP1a0rgqM0

copyright: Helmut Schenkel Brunner


Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be stable, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Black Heron status Least Concern

Migration

The movements of this species are little known, although it is thought to be sedentary, sometimes making local movements in response to seasonal rainfall and the appearance of temporary shallow-water feeding areas

Distribution map

Black Heron distribution range map

About the author

admin

Permanent link to this article: http://www.planetofbirds.com/ciconiiformes-ardeidae-black-heron-egretta-ardesiaca

Leave a Reply