Lesser Adjutant Leptoptilos javanicus


Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

IUCN Red list criteria met and history
Red List criteria met
Critically Endangered Endangered Vulnerable
- - A2cd+3cd+4cd

Red List history
Year Category Criteria
2016 Vulnerable A2cd+3cd+4cd
2013 Vulnerable A2cd+3cd+4cd
2012 Vulnerable A2cd+3cd+4cd
2008 Vulnerable A2c,d; A3c,d; A4c,d
2006 Vulnerable
2004 Vulnerable
2000 Vulnerable
1996 Vulnerable
1994 Vulnerable
1988 Threatened
Species attributes

Migratory status full migrant Forest dependency Medium
Land mass type Land-mass type - continent
Land-mass type - shelf island
Average mass 4651 g

Estimate Data quality
Extent of Occurrence breeding/resident (km2) 11,300,000 medium
Extent of Occurrence non-breeding (km2) 13,100,000 medium
Number of locations 11-100 -
Severely Fragmented -
Population and trend
Value Data quality Derivation Year of estimate
No. of mature individuals 5500-10000 poor estimated 2013
Population trend Decreasing poor suspected -
Decline (3 years/1 generation past) - - -
Decline (5 years/1 generation past) - - -
Decline (10 years/1 generation past) - - -
Decline (10 years/3 generation future) 30-49 - - -
Decline (10 years/3 generation past and future) 30-49 - - -
Number of subpopulations 2-100 - - -
Percentage in largest subpopulation 1-89 - - -
Generation length (yrs) 16.1 - - -

Population justification: A total population of 5,000 individuals was previously estimated by Hancock (1993), Choudhury (2000) and BirdLife International (2001). However, more extensive survey effort in recent years has led to upward revisions of some national totals: in particular the Cambodian population is now thought to number perhaps 1,500-3,500 pairs or 3,000-7,000 mature individuals (Goes 2013, S. Mahood in litt. 2013). Taking this total and perhaps 1,200 mature individuals in India, c.300 in Malaysia, 200-700 in Nepal, 250-400 individuals in Myanmar (Zöckler et al 2014; in litt) plus an unknown number in Indonesia (previously estimated at 2,000 individuals in 1993 but may have severely declined since), and assuming only very small numbers elsewhere, the global population probably numbers 5,500-10,000 mature individuals (roughly equating to 8,000-15,000 individuals).

Trend justification: This species's population is suspected to be declining rapidly, in line with increasing levels of felling of colony nest trees, drainage and conversion of wetland feeding areas, agricultural intensification, pesticide use, disturbance and large-scale development in coastal areas, but, most seriously, the persistent and unregulated harvesting of eggs and chicks from colonies.
Successes in parts of Cambodia are likely to be isolated and may be short-term (C. Robson in litt. 2013), and declines are predicted to be ongoing elsewhere in the country . In Indonesia, estimates in South Sumatra and Jambi provinces in 1984-1986 were 514 birds (388-620) and 272 (152-475) birds respectively, while surveys in these provinces in 2001-2004 estimated only 124 birds (30-318) and 7 birds (2-17) respectively (M. Iqbal in litt. 2013), suggesting that very rapid declines may have occurred on Sumatra.

Country/territory distribution
Country/Territory Occurrence status Presence Resident Breeding Non-breeding Passage
Bangladesh N Extant Yes
Bhutan V Extant
Brunei N Extant Yes
Cambodia N Extant Yes
China (mainland) N Possibly Extinct Yes
India N Extant Yes
Indonesia N Extant Yes
Laos N Extant Yes
Malaysia N Extant Yes
Myanmar N Extant Yes
Nepal N Extant Yes
Singapore N Extinct Yes
Sri Lanka N Extant Yes
Thailand N Extant Yes
Vietnam N Extant Yes

Important Bird and Biodiversity Areas (IBA)
Country/Territory IBA Name
Vietnam U Minh Thuong
Vietnam Tram Chim
Vietnam Chu Prong
Vietnam Yok Don
Vietnam Ya Lop
Vietnam Nam Cat Tien
Vietnam Binh Dai
Bangladesh Hakaluki Haor
Bangladesh Sunderbans (East, South, West Wildlife Sanctuaries)
Bangladesh Teknaf Game Reserve
Brunei Wasan
Brunei Brunei Bay
Brunei Ulu Temburong
Brunei Seria Coast
Indonesia Rawa Tapus
Indonesia Pesisir Timur Pantai Sumatera Utara
Indonesia Bukit Tigapuluh
Indonesia Hutan Rawa Gambut Siak-Kampar
Indonesia Kerumutan
Indonesia Pesisir Riau Tenggara
Indonesia Siak Kecil
Indonesia Rawa Pesisir Pantai Barat Tapanuli Selatan (Angkola)
Indonesia Hutan Rawa Gambut Barumun-Rokan
Indonesia Berbak
Indonesia Pesisir Pantai Jambi
Indonesia Sembilang
Indonesia Trumon - Singkil
Indonesia Tanjung Selokan
Indonesia Tanjung Koyan
Indonesia Way Kambas
Indonesia Bukit Barisan Selatan
Indonesia Gunung Tilu-Simpang
Indonesia Muara Gembong - Tanjung Sedari
Indonesia Rawa Danau
Indonesia Ujung Kulon
Indonesia Segara Anakan - Nusa Kambangan
Indonesia Solo Delta
Indonesia Gunung Bromo Tengger-Semeru
Indonesia Baluran
Indonesia Alas Purwo
Indonesia Bali Barat
Indonesia Danau Sentarum
Indonesia Muara Kendawangan
Indonesia Gunung Palung
Indonesia Tanjung Puting
Indonesia Hutan Kahayan
Indonesia Lembah Sungai Negara
Indonesia Delta Mahakam
Indonesia Lahan Basah Mahakam Tengah
Indonesia Pulau Moyo
Malaysia Bako-Buntal Bay
Malaysia Brunei Bay (Malaysia)
Malaysia Endau-Rompin
Malaysia Klias peninsula
Malaysia Kulamba Wildlife Reserve
Malaysia Kinabatangan floodplain
Malaysia Matang coast
Malaysia North-central Selangor coast
Malaysia Panti forest
Malaysia Teluk Air Tawar-Kuala Muda coast
Malaysia South-west Johor coast
Malaysia South-east Pahang peat swamp forest
Malaysia Tempasuk plains
Malaysia Sadong-Saribas coast
Malaysia Pulau Bruit National Park
Malaysia Loagan Bunut National Park
Myanmar Indawgyi Lake Wildlife Sanctuary and surroundings
Myanmar Hukaung Valley
Myanmar Upper Mogaung Chaung basin
Myanmar Ayeyarwady River: Myitkyina to Sinbo Section
Myanmar Ayeyarwady River: Bhamo Section
Myanmar Ayeyarwady Delta (including Meinmahla Kyun)
Myanmar Pachan
Thailand Inner Gulf of Thailand
Thailand Khao Ang Ru Nai
Thailand Khao Sam Roi Yot
Thailand Thung Kha
Thailand Ko Phra Thong
Thailand Palian Lang-ngu
Thailand Thale Noi
Vietnam Chu M'lanh
Sri Lanka Ampara
Sri Lanka Madura Oya
Sri Lanka Rugam Tank
Sri Lanka Kantale Tank
Sri Lanka Senanayake Samudraya / Nilgala
Sri Lanka Anuradhapura
Sri Lanka Padaviya
Sri Lanka Minneriya / Girithale / Kaudulla
Sri Lanka Polonnaruwa
Sri Lanka Udawalawa
Sri Lanka Bundala complex
Sri Lanka Yala
Thailand Chaloem Pra Kiet (Pa Phru to Daeng)
Indonesia Rawa Tulang Bawang
Cambodia Prek Toal
Cambodia Dei Roneat
Cambodia Upper Stung Sen Catchment
Cambodia Boeung Chhmar / Moat Khla
Cambodia Stung / Chi Kreng / Kampong Svay
Laos Dong Khanthung
Cambodia Chhep
Cambodia Stung / Prasat Balang
Cambodia Chhnuk Tru
Cambodia Lower Stung Sen
Cambodia Veal Srongae
Laos Xe Kong Plains
Cambodia Western Siem Pang
Cambodia Stung Sen / Santuk / Baray
Cambodia Ang Tropeang Thmor
Cambodia Sesan River
Cambodia Northern Santuk
Cambodia Lomphat
Laos Dong Kalo
Cambodia Upper Srepok Catchment
Cambodia Mondulkiri - Kratie Lowlands
Cambodia Snoul / Keo Sema / O Reang
Cambodia Sre Ambel
Cambodia Stung Kampong Smach
Cambodia Prek Taek Sap
Myanmar Karathuri
India Manjira Wildlife Sanctuary
India D'Ering Memorial Wildlife Sanctuary
India Dibang Reserve Forest and adjacent areas
India Amchang Hills
India Barail Range
India Bauwwa Beel
India Behali Reserve Forest
India Bherjan-Borajan-Podumoni Wildlife Sanctuary
India Bordoibam-Bilmukh Bird Sanctuary
India Bordoloni - Sampora
India Chakrashila Complex
India Chandubi Lake and adjoining areas
India Deobali Jalah, Sialmari, Haibargaon, Khutikatia (Nagaon)
India Dhansiri Reserve Forest
India Dibru - Saikhowa Complex
India Deepor Beel Bird Sanctuary
India Dum Duma, Dangori and Kumsong Reserve Forests
India East and North Karbi Anglong Wildlife Sanctuaries
India Garampani, Nambor and Doigrung
India Gibbon (Hollongapar) Sanctuary
India Innerline, Katakal and Barak Reserve Forests
India Jamjing and Sengajan
India Jengdia Beel and Satgaon
India Jhanjimukh - Kokilamukh
India Kaziranga National Park
India Kuarbari Dalani
India Laokhowa and Burhachapori Sanctuaries
India Lumding - Marat Longri
India Majuli
India Manas National Park
India Nameri National Park
India Orang National Park
India Pabho Reserve Forest
India Pabitora Wildlife Sanctuary
India Pani-Dihing Bird Sanctuary
India Ripu and Chirang Reserve Forests
India Sibsagar Tanks
India Son Beel
India Subansiri
India Tamaranga - Dalani - Bhairab Complex
India Tirap - Burhidihing
India Upper Dihing (East) Complex
India Upper Dihing (West) Complex
India Urpod Beel
India Gogabil Pakshi Vihar, Baghar Beel and Baldia Chaur
India Kusheshwarsthan
India Mokama Taal (Barah) Wetlands
India Valmiki Tiger Reserve and Saraiyaman Lake
India Okhla Bird Sanctuary
India Carambolim Wetlands
India Velavadar National Park
India Bhindawas Wildlife Sanctuary
India Sultanpur National Park
India Udhuwa Lake Bird Sanctuary
India Bandipur National Park
India Bhadra Wildlife Sanctuary
India Dandeli Wildlife Sanctuary
India Kukkarahalli Tank
India Nagarhole National Park
India Someshwara Wildlife Sanctuary
India Amarambalam Reserved Forest - Nilambur
India Nagzira Wildlife Sanctuary
India Navegaon National Park
India Sanjay Gandhi National Park
India Tadoba National Park and Andhari Tiger Reserve
India Loktak Lake and Keibul Lamjao National Park
India Bandhavgarh National Park
India Dihaila Jheel and other wetlands
India Kanha National Park
India Madhav National Park
India Panna National Park
India Bhitarkanika Wildlife Sanctuary and National Park
India Nalabana Bird Sanctuary (Chilika Lake)
India Harike Lake Bird Sanctuary
India Keoladeo National Park and Ajan Bande
India Ranthambore National Park and Tiger Reserve
India Mudumalai National Park
India Gumti Wildlife Sanctuary
India Dudhwa National Park
India Katerniaghat Wildlife Sanctuary and Girijapur Barrage
India Kishanpur Wildlife Sanctuary
India Sur Sarovar Bird Sanctuary
India Corbett Tiger Reserve
India Buxa Tiger Reserve (National Park)
India Farakka Barrage and adjoining area
India Gorumara National Park
India Jaldapara Wildlife Sanctuary
India Kulik (Raiganj) Bird Sanctuary
India Mahananda Wildlife Sanctuary
India Naya Bandh Wetland Complex
India Sundarbans Biosphere Reserve (National Park)
Nepal Urlabari forest groves
Malaysia Pondok Tanjung Forest Reserve
Nepal Nawalparasi forests
India The Chapories of Lohit Reserve
India Bhagwan Mahavir Wildlife Sanctuary (including Molem)
Indonesia Tanjung Koyan-Selokan
Laos Xe Khampho
Laos Xe Pian
Vietnam Yok Don NP
Laos Xe Khampho / Xe Pian
Nepal Jagdishpur Reservoir
Nepal Barandabhar forests and wetlands
Nepal Bardia National Park
Nepal Chitwan National Park
Nepal Dang Deukhuri foothill forests and west Rapti wetlands
Nepal Dharan forests
Nepal Farmlands in Lumbini area
Nepal Ghodaghodi Lake
Nepal Koshi Tappu Wildlife Reserve and Koshi Barrage
Nepal Mai Valley forests
Nepal Parsa Wildlife Reserve
Nepal Sukla Phanta Wildlife Reserve
Cambodia Bassac Marsh
Myanmar Kamaing
Myanmar Tanai River
Cambodia Central Oddar Meanchey
Myanmar Ayeyarwady River: Shwegu Section
Myanmar Meinmahla Kyun
Thailand Ao Pattani
Thailand Bung Boraphet
Myanmar Kadonkani
Myanmar Pyaungbya River
Myanmar Pyin-ah-lan
India Barak River
India Botha Beel
India Deobali Jalah
India Manaha Complex
India Nagaon Township
India Sareswar Beel
India Tirap-Paktai and Namphai
India Marat Longri Wildlife Sanctuary
India Maguri and Motapung Beels
India Manas Reserve Forest
India Innerline (West) and Katakhal Reserve Forests
India Dadara-Pasariya-Singimari
India Barail Wildlife Sanctuary
India Chirang Reserve Forest
India Ripu Reserve Forest
India Pilibhit Tiger Reserve
India Amangarh Reserve Forest
India Innerline (East) and Barak Reserve Forests
India Jhilmil Jheel Conservation Reserve
India Kachhudah Lake and Mahananda River Course
India Keibul Lamjao National Park
India Kajra Dhar and Raniganj Protected Forest
India Heerakund Reservoir and Debrigarh Wildlife Sanctuary
India Achanakmar Wildlife Sanctuary and Maniyari Reservoir
India Loktak Lake
India Lumding Reserve Forest
India Hazaribagh Wildlife Sanctuary

Habitats & altitude
Habitat (level 1) Habitat (level 2) Importance Occurrence
Artificial/Aquatic & Marine Artificial/Aquatic - Water Storage Areas (over 8ha) suitable resident
Artificial/Terrestrial Arable Land suitable resident
Forest Subtropical/Tropical Dry suitable resident
Forest Subtropical/Tropical Moist Lowland major resident
Marine Coastal/Supratidal Coastal Brackish/Saline Lagoons/Marine Lakes major resident
Marine Intertidal Mangrove Submerged Roots major resident
Marine Intertidal Mud Flats and Salt Flats major resident
Marine Intertidal Salt Marshes (Emergent Grasses) major resident
Savanna Dry suitable resident
Wetlands (inland) Permanent Freshwater Lakes (over 8ha) major resident
Wetlands (inland) Permanent Freshwater Marshes/Pools (under 8ha) major resident
Wetlands (inland) Permanent Rivers/Streams/Creeks (includes waterfalls) major resident
Altitude   Occasional altitudinal limits  

Threats & impact
Threat (level 1) Threat (level 2) Impact and Stresses
Agriculture & aquaculture Annual & perennial non-timber crops - Agro-industry farming Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture Marine & freshwater aquaculture - Scale Unknown/Unrecorded Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation, Ecosystem conversion
Biological resource use Fishing & harvesting aquatic resources - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation
Biological resource use Hunting & trapping terrestrial animals - Intentional use (species is the target) Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Reduced reproductive success, Species mortality
Biological resource use Logging & wood harvesting - Unintentional effects: (large scale) [harvest] Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Ecosystem degradation
Biological resource use Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest] Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation
Energy production & mining Mining & quarrying Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation, Ecosystem conversion
Human intrusions & disturbance Work & other activities Timing Scope Severity Impact
Ongoing Majority (50-90%) Slow, Significant Declines Medium Impact: 6
Species disturbance
Pollution Agricultural & forestry effluents - Type Unknown/Unrecorded Timing Scope Severity Impact
Ongoing Minority (<50%) Slow, Significant Declines Low Impact: 5
Ecosystem degradation

Purpose Primary form used Life stage used Source Scale Level Timing
Food - human - - Non-trivial Recent
Pets/display animals, horticulture - - International Non-trivial Recent

Recommended citation
BirdLife International (2022) Species factsheet: Leptoptilos javanicus. Downloaded from on 01/12/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from on 01/12/2022.