black-headed ibis, Oriental white ibis, Indian white ibis, black-necked ibis

Description:

near threatened. The black-headed ibis (Threskiornis melanocephalus), also known as the Oriental white ibis, Indian white ibis, and black-necked ibis, is a species of wading bird of the ibis family Threskiornithidae which breeds in the South- and Southeast Asia from India to the west and as far east as Japan. It is the only native ibis species in its range that has an overall white plumage with a black neck and head. The down-curved beak and legs are also black. Though often referred to as a wetland species, the black-headed ibis forages in a range of natural and man-made habitats. This species of ibis nests only during the rainy season (or monsoon). The black-headed ibis is one of several large waterbird species in south and south-east Asia, with adults measuring 65–76 cm in length. The white plumage is starkly contrasted against a conspicuous naked black neck and head, and black down-curved beak. Tails of adults bear light grey ornamental feathers that turn jet black during the breeding season. During the breeding season, bare patches under the wing turn blood-red. The head of some breeding adults gain a blueish tinge, or very rarely have a pink or bright red patch behind the neck. Some breeding adults also develop tufts of white feathers behind the neck, and rarely also get a yellowish colouration on the breast and back. Sexes are identical but juveniles are identifiable from adults in having greyish feathering on the neck and speckled brown-grey feathering on the wings and back. Like storks and spoonbills, it lacks a true voice-producing mechanism and is silent except for ventriloquistic grunts uttered by pairs at the nest.

Habitat:

Yala National Park. coastal lowlands. The Yala area is mostly composed of metamorphic rock belonging to the Precambrian era and classified into two series, Vijayan series and Highland series. Reddish brown soil and low humic grey soil are prominent among six soil types. Yala is situated in the lowest peneplain of Sri Lanka, which extends from Trincomalee to Hambantota. Topographically the area is a flat and mildly undulating plain that runs to the coast with elevation is 30 metres (98 ft) close to the coast while rising in the interior to 100–125 metres (328–410 ft). The national park is situated in the dry semi-arid climatic region and rain is received mainly during the northeast monsoon. The mean annual rainfall ranges between 500–775 millimetres (19.7–30.5 in) while the mean temperature ranges between 26.4 °C (79.5 °F) in January to 30 °C (86 °F) in April. It is windier in Yala, during the southwest monsoon compared to the wind during the northeast monsoon with wind speeds from 23 kilometres per hour (14 mph) to 15 kilometres per hour (9.3 mph). Water is abundant after the northeast monsoon, but during the dry season surface water becomes an important factor. The bodies of surface water appear in the forms of streams, tanks, waterholes, rock pools, and lagoons. Waterholes occur in low lying places while rock pools of varying size are capable of containing water year-round, and are hence an important source of water for elephants. For many water birds and water buffaloes natural waterholes are ideal habitats. Such reservoirs are largely concentrated to the Block I followed by Block II. Several tanks are there including, Maha Seelawa, Buthawa, Uraniya, and Pilinnawa tanks. Many rivers and streams flow in a southeasterly direction, originating in the highlands of adjacent Uva and central hills. Kumbukkan Oya in the east and Menik River and its tributaries in the west flow across the park, and provide an important water source in the dry season to wild animals of the park. Normally the streams of the park are dry during the drought season. These rivers and streams exhibit a degree of runoff fluctuations between wet and dry seasons. Kumbukkan Oya discharges seven times as much water in the rainy season than in the dry season. A number of lagoons are situated along the coast line of the park.