Chiefly occupies extensive, undisturbed, freshwater wetlands, including swamps, rivers, lakes, lagoons, flooded grassland, water meadows, and billabongs (Rasmussen and Anderton 2012, Elliott et al. 2020), apparently up to 1,200 m (Grimmett et al. 1999, Robson 2000). The species will also visit floodplains and irrigated crops, particularly rice paddies during the monsoon season, as natural wetlands become too flooded to find food (Sundar 2004). In arid Australia, the species will visit artificial water bodies, including irrigation storage and sewage ponds (Elliott et al. 2020). Less often, it occurs along the coast in mangroves, mudflats, beaches, salt marshes and tidal creeks (Elliott et al. 2020). In Cambodia, frequents the lowlands and low hills of forested wetlands, grasslands, reservoirs, and coastal mudflats (CBGA 2019).

The species is a generalist carnivore, feeding primarily on fish, including eels (which are a key prey item in New South Wales) and catfish, but also on frogs, lizards, snakes, hatchling turtles, freshwater turtles, tortoises and their eggs, and a range of crustaceans and insects (Whiting and Guinea 1999, Dorfman et al. 2001, Maheswaran and Rahmani 2002, Ishtiaq et al. 2004, Chauhan and Andrews 2006, Sundar 2011b, Elliott et al. 2020). Additionally, the species is known to predate waterbirds (Ishtiaq et al. 2004, Sundar 2011b).

The subspecies E. a. asiaticus occurs predominantly in India, where the largest and most stable breeding population occurs in the Etawah and Mainpuri districts of Uttar Pradesh in the upper Gangetic floodplains (Sundar 2003, 2005, 2011a, Rahmani 2012). The subspecies also has small breeding populations in Sri Lanka, Kachin State in Myanmar (Tordoff et al. 2007), Cambodia (Goes 2013), Nepal (Prashant et al. 2017, Baral and Poudyal 2020) and potentially the far south of Lao PDR near the Cambodian border (Duckworth et al. 1999, Evans et al. 2000). It is a rare visitor to Bhutan (Elliott et al. 2020). The species previously bred in Pakistan, but its current status is very poorly known; in Bangladesh it is probably extinct as a breeding species and now occurs only as a vagrant (Grimmett et al. 1998, BirdLife International 2001, Elliott et al. 2020). The subspecies previously occurred in Thailand, and presumably bred, but is now extinct (Treesucon and Limparungpatthanakij 2018). Apparently, the species previously occurred (and is now extinct) in Sundaic Indonesia (MacKinnon and Phillips 1993), but there is only a single record from 1908 on Java (Wells 1999), and its status in this region is therefore uncertain.

The subspecies E. a. australia occurs broadly from New South Wales, Queensland, Northern Territory, and Western Australia, Australia, with a small proportion of the population also in southern Papua New Guinea (Clancy et al. 2021).

Conservation Actions Underway
In Australia, the species is listed as Endangered in New South Wales (NSW Government 1999). It has been upgraded to Schedule II of the Indian Wildlife (Protection) Act (SoIB 2023). It occurs in a number of protected areas including several national parks in Australia and India (UNEP-WCMC and IUCN 2024). A long-term monitoring study has been established in India to understand impacts of land use change and rainfall patterns on the species (Sundar 2011a).

Conservation Actions Proposed
Long-term monitoring of breeding timing and success, and monitoring of juveniles, would be beneficial and help establish local trends, and colour-banding programs should continue (Clancy and Kingsford 2015). Further fieldwork is required to improve the precision of habitat mapping and territory mapping (Clancy and Andren 2010). Continue to monitor wetlands in northern Cambodia (using photo-traps) to help understand breeding biology and success (K. S. G. Sundar in litt. 2007). Range wide species-specific surveys are need to help estimate an accurate and precise population size, including regional population sizes.

Unprotected essential habitat needs to be formally protected, especially in India and South-East Asia. Positive management is required to maintain stable populations, including but not limited to the protection and restoration of natural wetlands (Sundar 2011a, Clancy and Kingsford 2015). Specifically, wetlands need to be managed to reduce pollution from run-off, and protect them from being drained or deepened; particularly, management should focus on maintaining healthy populations of important prey species (Clancy 2011).

Further research is needed on the species' breeding biology, feeding ecology and diet (Clancy and Kingsford 2015). Genetic and telemetry studies would contribute to the understanding of population fragmentation and juvenile dispersal in heavily cultivated landscapes, and aid in landscape planning (Sundar 2004). Research into future habitat loss as a result of climate change can aid conservation planning and habitat management. Further research into trade, hunting and collection for zoos is needed to understand the impact of this threat and how to mitigate it.

In India, strengthening regional policies to include habitat management and conservation in agricultural expansion plans, and including protection of important farmlands and farmland biodiversity in federal and regional policies is suggested (Sundar 2011a). Educational and awareness programs can aid in reporting of the species and reporting and monitoring of nest sites (Clancy and Andren 2010).