(2227) Demiegretta sacra sacra.
The Eastern Reef-Heron.
Ardea sacra Gmelin, Syst. Nat,, i, p. 640 (1788) (Tahiti). Lepterodius sacer. Blanf. & Oates, iv, p. 391.
Vernacular names. None recorded.
Description. Two phases. One pure white, the other dark slaty-black, the chin generally white; the abdomen browner and paler than the back. The feathers of the lower fore-neck, overhanging the breast, are long and lanceolate ; there is a crest of short, thick feathers and there are long lanceolate plumes on the scapulars and interscapulars, the ends of a paler slaty-grey than the rest of the plumage.
Pied birds in every intermediate state of plumage may be found but these are generally young and adults are nearly always either pure white or all slaty.
Colours of soft parts. Iris yellow; bill horny-brown above, yellowish at the base and on lower culmen, often yellow all over in white birds; legs varying from pale yellowish-green in white birds to deep dull greenish or nearly black in the dark individuals.
Measurements. Wing 250 to 293 mm.; tail 93 to 98 mm.; tarsus 72 to 77 mm ; culmen 70 to 86 mm.
Distribution. Andamans, Nicobars, coasts of Burma, the Malay Peninsula and Archipelago to Australia.
Nidification. Hop wood found this Heron breeding in Oyster Island, off: the Arrakan coast, in May but in the An damans, Nicobars and islands off the Malay coast the usual breeding-time is from the end of June to July. A few birds breed during the last week in May but, on the other hand, many do not lay until August or even September. They breed in colonies, making their nests on the Mangrove swamps along the shores, often placing them within a few inches of the water at high tide, whilst they seldom place them more than six feet above it. The nests are typical Herons' nests but all those taken in the Andamans and Nicobars were close to the sea. On Oyster Island Hopwood also found them breeding on scrub near the edge of the island but Shopland took nests from a patch of thorny jungle in the middle of the island, whilst Davison was told that on Trinkut Island the birds built on coco-nut palms. The eggs, most often three in number but occasionally four or even five, are pale sea-green or blue-green in colour, paler than most Herons' eggs but not quite so pale as those of the genus Bubulcus. Fifty eggs average 44.8 x 33.3 mm.: maxima 48.1 X 32.2 and 44.4 x 34.1 mm.; minima 42.5 X 31.8 and 47.5 x 31.7 mm.
Habits. The Reef-Herons are purely coastal birds and, except when breeding, very solitary, quiet birds, sitting hunched up on some mangrove root, almost invisible in the shadows. They feed on small mud-fish, Crustacea and mollusca, which they find in quantity in all the muddy shores they frequent. They fly with the usual deliberate wing motion of the Herons, yet are capable of considerable speed when frightened. They are very crepuscular in their habits.