Greater adjutant  (Leptoptilos dubius)

Greater adjutant standing on branch

Facts

Kingdom Animalia
Phylum Chordata
Class Aves
Order Ciconiiformes
Family Ciconiidae
Genus Leptoptilos (1)
Size Length: 145 – 150 cm (2)

Status

The greater adjutant is classified as Endangered (EN) on the IUCN Red List 2007 (1) and is listed under Schedule IV of the Wildlife Act 1972 (3).

Description

This huge stork has a naked pink head, a very thick yellow bill and a low-hanging neck pouch. The neck ruff is white and, other than the pale grey leading edge of each wing, the rest of the greater adjutant's body is dark grey. Juveniles have a narrower bill, thicker down on the head and neck and entirely dark wings (2).

Range

The greater adjutant was formerly found in South and Southeast Asia, but there are now just two small and separate breeding populations; one in Assam, India and one in Cambodia. A migratory bird, the greater adjutant also visits Viet Nam, Thailand and Burma when not breeding (3).

Habitat

Inhabits wetland habitats, especially those that are partially dry and where fish are abundant, including lakes, swamps, river beds, stagnant pools and paddy fields (3).

Biology

Gathering in compact colonies at the start of the dry season in October, the greater adjutant nests on large, widely branched trees with few leaves (4). It constructs a large platform of sticks with an outer layer of bamboo stems and lines this with leaves. Two to four eggs are laid between November and January. After 28 to 30 days, the eggs hatch, and the nestlings are cared for until April. At the start of the wet season, the greater adjutants migrate to northern India (3).

The greater adjutant feeds by sweeping its bill under the surface of the water, or by probing into the substrate. It will consume carrion, fish, frogs, reptiles, crustaceans, large insects and even injured ducks. It is also known to feed in human refuse dumps, where it will take food from other scavengers, including vultures (3).

Threats

Loss of nesting habitat and feeding sites has had a huge impact on this stork species. Suitable wetland habitats have been cleared, drained, polluted with pesticides and disturbed by humans. Adult birds are hunted and chicks and eggs are collected for trade (3).

Conservation

Whilst legally protected in India, Bangladesh, Burma, Thailand, Cambodia and Laos, and occurring in three National Parks in Assam, India, the greater adjutant still suffers from hunting and egg collection due to poor enforcement of protection. There has been some successful control of egg and chick collection following efforts by the Wildlife Protection Office Staff in Cambodia, which resulted in higher numbers of storks the following year. It has been proposed that the greater adjutant should be moved from Schedule IV to Schedule I of the Indian Wildlife Act of 1972 to give it greater priority. Effective land management is necessary for the survival of this species, particularly the control of pesticide use around feeding areas and the protection of feeding areas and nesting sites found outside protected areas. Further research into the seasonal movements of these birds and the threats that face them is also important (3).

Further Information

For further information on the greater adjutant see:

Authentication

Authenticated (10/03/05) by BirdLife International.
http://www.birdlife.org

Carrion: Dead flesh.
Colonies: A group of organisms living together. Individuals in the group are not physiologically connected and may not be related, such as a colony of birds.
Crustacea: Diverse group of arthropods (a phylum of animals with jointed limbs and a hard chitinous exoskeleton) characterised by the possession of two pairs of antennae, one pair of mandibles (parts of the mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, slaters, woodlice and barnacles.

References

  1. IUCN Red List (May, 2008)
    http://www.iucnredlist.org
  2. Stattersfield, A.J. and Capper, D.R. (1998) Threatened Birds of the World. BirdLife International, Cambridge, U.K..
  3. BirdLife International. (2001) Threatened Birds of Asia: the BirdLife International Red Data Book. BirdLife International, Cambridge, UK.
  4. Singha, H., Rahmani, A.R., Couller, M.C. and Javed, S. (2002) Nesting ecology of the greater adjutant stork in Assam, India. Waterbirds, 25 (2): 214 - 220.