The lesser adjutant (Leptoptilos javanicus) is a large wading bird in the stork family Ciconiidae.

[8][9] It is found in India,[10] Nepal,[8] Sri Lanka,[11] Bangladesh (a colony with about 6 nests and 20 individuals was discovered near Thakurgaon in 2011),[12] Myanmar, Thailand, Vietnam, Malaysia, Laos, Singapore,[9] Indonesia and Cambodia.

[11] In Nepal, surveys in eastern districts had suggested that they preferentially use forested patches with small wetlands, largely avoiding crop fields.

[16][17][18] The lesser adjutant stalks around wetlands feeding mainly on fish, frogs, reptiles, large invertebrates, rodents, small mammals and rarely carrion.

During pair formation, female birds lift their heads in a scooping motion with bill-clattering (called the "Balancing Posture").

[4] In eastern Nepal, four colonies consisting of 61 nests were all built on the tree species Haldina cordifolia and Bombax ceiba.

[23] Another study the subsequent year across five locations along lowland Nepal monitored 65 colonies with 206 nests from which 280 chicks fledged, and the most frequently used tree species were B. ceiba, H. cordifolia and F. religiosa respectively.

[23] Religious beliefs and agro-forestry practices appear to be responsible for retaining trees that are preferred by lesser adjutants for locating their colonies.

Colonies located on trees in agricultural landscapes of lowland Nepal had a higher breeding success relative to colonies located on trees in forested areas or protected wetland preserves suggesting that current agricultural practices with one season of flooded crops (rice during the monsoon season) followed by winter crops that need some pulsed irrigation (e.g. wheat) are conducive to Lesser Adjutant breeding.

[18] Adult storks took an average of 30 minutes to return to nests with food for nestlings and fledglings, though there was considerable variation in this measure.

[8] Subsequent work in South Asia, that has been far more detailed and nuanced, with analyses covering robust colony-level and landscape-level evaluations, have shown these assumptions to be incorrect and likely part of generic assumptions that appear to be overlaid on all agricultural areas and birds by scientists in developed countries.

[16][17][18][23] Like for many other large waterbirds, the south-east Asian populations of Lesser Adjutant storks appear to be greatly at risk due to a combination of hunting and habitat destruction.

[3][24] Subsequently, additional research has shown their population sizes to be much higher than previous estimates that were based on guesses.