Pacific Reef Heron (Egretta sacra)

Pacific Reef Heron

[order] CICONIIFORMES | [family] Ardeidae | [latin] Egretta sacra | [authority] Gmelin, 1789 | [UK] Pacific Reef Heron | [FR] Aigrette sacree | [DE] Riffreiher | [ES] Garceta de arrecife | [NL] Oostelijke Rifreiger

Subspecies

Monotypic species

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

The species displays an unusual, non-sexual dimorphism, with some members having entirely white plumage and others (the larger portion) being charcoal-grey. The reason for the color variation or “morph,” is unknown, though it is most commonly thought to be related to camouflage. Dark morph
The two colour morphs, Ko Tao, ThailandEastern Reef Egrets have very short, yellow legs, and the grey variety’s throats and chins are marked by a narrow, white stripe. They have brown beaks, gold-yellow colored eyes and the surrounding areas of their faces are normally of a greenish to yellow cast.

Listen to the sound of Pacific Reef Heron

[audio:http://www.planetofbirds.com/MASTER/CICONIIFORMES/Ardeidae/sounds/Pacific Reef Heron.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 90 cm wingspan max.: 110 cm
size min.: 57 cm size max.: 66 cm
incubation min.: 25 days incubation max.: 28 days
fledging min.: 35 days fledging max.: 38 days
broods: 1   eggs min.: 2  
      eggs max.: 4  

Range

Oriental Region, Australasia : Southeast Asia to New Zealand. They are found in many areas of Asia including the oceanic region of India, Southeast Asia, Japan, Polynesia, and in Australia, Tasmania and New Zealand.

Habitat

Freshwater marshes, ricefields and inland waters also rocky and sandy shoreline and/or beaches

Reproduction

The species lay clutches of eggs year round in colonies in the jungle, between palms and mangroves or in cavities of old buildings. Two to three paled greenish-blue eggs are laid in nests constructed from branches and blossoms. Males and females share brooding tasks. They normally have a 28-day brood period. After chicks are hatched, parents provide approximately 5 weeks of support.

Feeding habits

Their food sources are made up predominantly of varieties of ocean-based fish, crustaceans and molluscs.

Video Pacific Reef Heron

httpv://www.youtube.com/watch?v=vgr-CI88gNg

copyright: Juan Sanabria


Conservation

This species has a very 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 is very large, and hence does not 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.
Pacific Reef Heron status Least Concern

Migration

Sedentary, with some-post breeding dispersal: chick ringed at Pulau Dua (W Java) recovered 40 km away 3 months later; several birds ringed in Capricorn Is (off Queensland, E Australia) recovered on coast of Queensland. Some seasonal movements, e.g. large numbers reach Sentubong (Borneo) in spring, or New Zealand with large post-breeding congregations as late as Jun. Accidental to North Korea.

Distribution map

Pacific Reef Heron distribution range map

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