Lesser Adjutant

The lesser adjutant (Leptoptilos javanicus) is a stately wading bird belonging to the stork family Ciconiidae. It is characterized by its upright stance and a distinctive bare head and neck, lacking the pendant pouch seen in some related species. This bird is a large creature, with a length of 87–93 cm when measured from bill to tail, and it stands about 110–120 cm tall. The lesser adjutant tips the scales at 4 to 5.71 kg.

Identification Tips

When compared to the greater adjutant, the lesser adjutant is generally smaller with a straight upper bill edge, or culmen, measuring 25.8–30.8 cm. The base of the bill is paler, and the bird appears slightly trimmer and less hunch-backed. The skullcap is paler, and the upper plumage is uniformly dark, giving it an almost all-black appearance. The head and neck are nearly naked but for a few hair-like feathers. The upper shank, or tibia, is grey, and the tarsus measures 22.5–26.8 cm. The belly and undertail coverts are white. Juveniles resemble adults but have more feathers on the nape and are generally duller. During the breeding season, adults exhibit a reddish face and an orange neck, with copper spots on the larger median wing coverts and white edging on the inner secondary coverts and tertials. In flight, the retracted neck can sometimes be mistaken for the pouch of the greater adjutant.

Habitat

The lesser adjutant is often found in large rivers and lakes within well-wooded regions, freshwater wetlands in agricultural areas, and coastal wetlands, including mudflats and mangroves.

Distribution

This widespread species is found from India through Southeast Asia to Java. It is mainly distributed in the eastern states of India, such as Assam, West Bengal, and Bihar, and is extremely rare in southern India. In Sri Lanka, it is found in lowland areas largely within protected areas, as well as in forested wetlands and crop fields.

Behaviour

The lesser adjutant is a solitary bird, except during the breeding season when it forms loose colonies. It stalks around wetlands, feeding mainly on fish, frogs, reptiles, large invertebrates, rodents, small mammals, and occasionally carrion. It locates prey visually, sometimes perching on high vantage points to scan for food. The bird is largely silent but may clatter its bill, hiss, and moan at the nest. Courtship involves a "Balancing Posture" with bill-clattering, and during the "Arching display," adults extend their neck and may emit a hoarse wail.

Breeding

The lesser adjutant breeds in loose colonies, with no more than 20 nests per colony. The breeding season varies by region, with nests being large platforms of sticks placed on tall trees. The clutch consists of two to four white eggs, and the incubation period is 28–30 days. Breeding success is positively correlated with colony size, possibly due to reduced predation.

Similar Species

The only species that might be confused with the lesser adjutant is the greater adjutant. However, the lesser adjutant is smaller, with a straighter bill and lacks the hunched back of its relative.

Diet and Feeding

The lesser adjutant's diet consists of fish, frogs, reptiles, large invertebrates, rodents, small mammals, and occasionally carrion. It hunts primarily by sight and may spend considerable time scanning for prey from elevated perches.

Conservation status

The lesser adjutant was previously classified as "Vulnerable" but has since been downlisted to "Near Threatened" due to new evidence showing higher population sizes and breeding success than previously estimated. Threats include habitat destruction and hunting, particularly in Southeast Asia. However, agricultural practices in some regions, such as lowland Nepal, seem to support their breeding.