Inland, birds inhabit natural and human-modified wetlands, both open and forested. Coastal populations frequent mangroves and intertidal flats. It nests colonially in large trees, and historically on cliffs, often at traditional sites in or adjacent to wetlands. It utilises small wetlands within Asian dry forest, and can breed some distance from these; shrinking of pools during the dry season and limited availability can lead to overlap with human uses and resulting disturbance.

Leptoptilos javanicus has an extensive range across South and South-East Asia, although from much of its former range it has now been extirpated. It occurs in India (where it is relatively widespread in the south and east) and Sri Lanka, east through the southern Himalayan foothills (including Nepal and southernmost Bhutan), Bangladesh and Myanmar. In South-East Asia it is extirpated from much of its range, but still occurs in most range states: Thailand, Lao PDR, Viet Nam, Cambodia and Peninsular Malaysia. It also occurs in the Greater Sundas: Borneo, Sumatra and Java. It is possibly now extinct in southern China.

Conservation Actions Underway
Important nesting colonies are found in several protected areas in India and Nepal. In Cambodia, population increases have been achieved at the Prek Toal colony (in the Tonle Sap Great Lake RAMSAR site) by the protection of breeding birds at Prek Toal, with the species no longer breeding anywhere else in South-East Asia. This scheme has achieved success by employing round-the-clock monitoring provided by a team of rangers—including former poachers and egg robbers—to increase breeding productivity; this work has been supported logistically and technically by WCS. Elsewhere in parts of Cambodia financial incentives have been offered to local residents for the protection of nests, resulting in much higher rates of nesting success (T. Evans in litt. 2006; Clements et al. 2013); although overall away from Prek Toal the population continues to decrease. In the Greater Sundas, forest cover loss has slowed since 2020, especially in Kalimantan's peatswamp forests, principally because of an expanding and increasingly effective protected area network.

Conservation Actions Proposed
Throughout its range, the principal needed conservation action for Lesser Adjutant is the protection of breeding colonies. In the Greater Sundas, this requires the protection of remaining lowland forests and ensuring that protected areas are adequately protected and financed. In South-East Asia, the greatest risk to this species is provided by the fact that the largest breeding population is now at Prek Toal, a site that continues to be subject to numerous threats (e.g. Morovati et al. 2023). In addition to mitigating these (particularly preventing further damage to the broader Tonle Sap landscape), safeguarding remaining populations in the Northern Plains, and establishing and protecting breeding populations elsewhere, should be considered a priority. A species action/recovery plan should be developed to best evaluate the ideas discussed here to enable this species to inhabit a greater percentage of its former range. In neighbouring Lao PDR, where this species was once presumably widespread through the country's lowlands (Duckworth et al. 1999), there is suitable habitat for breeding and foraging birds, with hunting probably the only obstacle to recolonisation (Timmins et al. in press). In Thailand, wetland bird populations have (partially) recovered in the past twenty years (P. Round pers. comm.) but Lesser Adjutant remains a very rare breeding species that is absent from most of its former breeding range; this country should also be considered a priority for population and range expansion over the next decade. Here, hunting is a less pervasive problem than Lao PDR and may therefore prove itself a more realistic and immediate possibility. Identifying sites and means of attracting birds to breed should be undertaken; sites close to the Cambodian border should be prioritised to facilitate natural recolonisation. Throughout the Indian Subcontinent, protecting colonies in protected areas and using community-led initiatives is the priority (see equivalent text for Leptoptilos dubius). Of particular concern is that the species' predilection for using large trees in agricultural landscapes means that they are currently poorly represented in the protected area network (e.g., in Nepal: Katuwal et al. 2023). The conservation status of this species remains precarious and its current Near Threatened status relies on the continued generating of good data: robust monitoring must therefore also continue. Remote sensing data (e.g. Global Forest Watch 2023) should also continue to be used to monitor trends in forest cover in its range.