The lesser adjutant (Leptoptilos javanicus) is a large wading bird in the stork family Ciconiidae. Like other members of its genus, it has a bare neck and head. It is however more closely associated with wetland habitats where it is solitary and is less likely to scavenge than the related greater adjutant. It is a widespread species found from India through Southeast Asia to Java.
A large stork with an upright stance, a bare head and neck without a pendant pouch, it has a length of 87–93 cm. The only confusable species is the greater adjutant, but this species is generally smaller and has a straight upper bill edge, measuring 25.8–30.8 cm in length, with a paler base and appears slightly trimmer and less hunch-backed. The skullcap is paler and the upper plumage is uniformly dark, appearing almost all black. The nearly naked head and neck have a few scattered hair-like feathers. The upper shank or tibia is grey rather than pink, the tarsus measures 22.5–26.8 cm. The belly and undertail are white. Juveniles are a duller version of the adult but have more feathers on the nape. During the breeding season, the face is reddish and the neck is orange. The larger median wing coverts are tipped with copper spots and the inner secondary coverts and tertials have narrow white edging. The wing chord measures 57.5–66 cm in length. Like others in the genus, they retract their necks in flight. In flight, the folded neck can appear like the pouch of the greater adjutant. Males and females appear similar in plumage but males tend to be larger and heavier billed.