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The Pacific reef heron (''Egretta sacra''), also known as the eastern reef heron or eastern reef egret, is a kind of heron. They are found in many areas of Asia including the oceanic region of India, Southeast Asia, East Asia, Polynesia, and in Australia, Tasmania and New Zealand. Pacific reef herons are medium-sized herons, reaching 57 to 66 cm in length. They have a wingspan of between 90 and 110 cm and reach an average weight of 400 grams. 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 colour variation or "morph", is unknown, though it is most commonly thought to be related to camouflage. Eastern 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 coloured eyes and the surrounding areas of their faces are normally of a greenish to yellow cast. Their food sources are made up predominantly of varieties of ocean-based fish, crustaceans and molluscs. 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. ==References== *1974: Bruce Campbell "The Dictionary of Birds in Colour", George Rainbird Ltd., London. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pacific reef heron」の詳細全文を読む スポンサード リンク
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