Lesser Adjutant Leptoptilos javanicus Horsfield, 1821 (Ciconiiformes: Ciconiidae) in the dry lowlands of Sri Lanka: distribution, ecology, and threats

Main Article Content

Thilina N. de Silva
Sumudu Fernando
Haritha B. de Silva
Parami Tennakoon


The Lesser Adjutant Leptoptilos javanicus is a globally threatened species of stork; in Sri Lanka, it is a scarce resident breeder, and the largest bird in the country, yet the population status and ecology of the species is poorly understood.  This study tracks the stork’s spatial distribution and habitat use within the island, along with aspects of its ecology.  Data was collected via field sampling and questionnaire surveys, over a period of five years across the lowlands of the country.  The bird was observed 184 times, with numbers per sighting ranging from 1–17 individuals.  The species’ distribution was restricted to dry lowlands (rainfall <2200mm, elevation <300m).  The bird showed preference for savannah/woody savannahs, dry mixed evergreen forests, permanent wetlands, and croplands, and was prominently found within protected areas.  Lesser Adjutants were generally solitary, except in the driest months of the year (i.e., August–September and March–April), which are probably the two breeding periods of the bird in Sri Lanka.  Except for an abandoned nest, no active nest was found.  Habitat loss and fragmentation, hunting pressure, agricultural intensification, and development projects were identified as potential threats faced by the species, which varied in magnitude across the country.


Article Details

Author Biographies

Thilina N. de Silva, Biodiversity Institute, University of Kansas, 1345 Jayhawk Blvd, Lawrence, KS 66045, USA

Thilina N. de Silva is PhD student of the Biodiversity Institute at the University of Kansas USA, studying ecology and evolution of weaverbirds (Family: Ploceidae). Completed bachelors at the University of Peradeniya with honors in Zoology. 


Sumudu Fernando, Biodiversity Institute, University of Kansas, 1345 Jayhawk Blvd, Lawrence, KS 66045, USA

Sumudu Fernando is PhD student of the Biodiversity Institute at the University of Kansas studying evolution, distribution patterns and speciation of Treepies and Blue-magpies. Completed bachelors at the University of Peradeniya Sri Lanka with first class honors in Zoology.


Haritha B. de Silva, Defenders of Wildlife Sri Lanka, PO Box: 42/11, Pragathi Mawatha, Uda Eriyagama, Peradeniya 20400, Sri Lanka

Haritha B. de Silva is undergraduate of University of Peradeniya. Research assistant entomological laboratory of Department of Zoology.  Secretary of ‘Defenders of Wildlife Sri Lanka’, an organization for wildlife conservation. 


Parami Tennakoon, Assistant Divisional Secretary, Divisional Secretariat, Dimbulagala 51031, Sri Lanka

Parami Tennakoon is Assistant Divisional Secretary at the Dimbulagala Divisional Secretariat. Obtained his bachelors degree from the University of Peradeniya with honors in Zoology. A wildlife enthusiast and a popular civil servant. Involved in community services in Dimbulagala.



Attygalle, P., K.B. Ranawana & T.N. de Silva (2012). Biodiversity and conservation importance of Manewakanda and Danduwellawa isolated hills in Kala Oya basin, Sri Lanka. http://journals.sjp.ac.lk/index.php/fesympo/article/view/657.

Electronic version accessed 24 July 2014.

BirdLife International (2013). Leptoptilos javanicus. The IUCN Red List of Threatened Species 2013. http://www.iucnredlist.org/details/22697713/0 Electronic version accessed September 2015.

Chowdhury, S.U. & M.D.S.H. Sourav (2012). Discovery of a Lesser Adjutant Leptoptilos javanicus breeding colony in Bangladesh. BirdingASIA 17: 57–59.

del Hoyo, J., A. Elliott & J. Sargatal (1992). Handbook of The Birds of The World. Vol.1. Lynx Edicions, Barcelona, 440–464pp.

DIVA-GIS (2014). Free spatial data for Sri Lanka. http://www.diva-gis.org/Data. Downloaded on 13 June 2014.

ESRI (2011). ArcGIS Desktop: Release 10. Redlands, CA: Environmental Systems Research Institute.

Geekiyanage, N. & D.K.N.G. Pushpakumara (2013). Ecology of ancient Tank Cascade Systems in island Sri Lanka. Journal of Marine and Island Cultures 2: 93–101.

Harrison, J. & T. Worfolk (1999). A Field Guide to the Birds of Sri Lanka. Oxford University Press, Oxford, 35–37pp.

Henry, G.M. (eds.) (1998). A Guide to the Birds of Sri Lanka, 3rd edition. K.V.G. de Silva & Sons, Kandy, 51–52pp.

Henry, G.M. (1955). A Guide to the Birds of Ceylon. Oxford University Press, London, 45pp.

IUCN (2006). Information Brief on Mangroves in Sri Lanka. http://cmsdata.iucn.org/downloads/sri_lanka_information_brief_of_mangroves.pdf. Downloaded on 27 July 2014.

Khadka, K.K. & R. Pandey (2013). Changes in the distribution of Lesser Adjutant storks Leptoptilos javanicus in South and Southeast Asia: A plausible evidence of global climate and land-use change effect? International Journal of Zoological Research 10(1): 9–14.

Kotagama, S. & P. Fernando (1994). A Field Guide to the Birds of Sri Lanka. Wildlife Heritage Trust, Colombo, 40pp.

MOE (2012). The National Red List 2012 of Sri Lanka; Conservation Status of the Fauna and Flora. Ministry of Environment, Colombo, Sri Lanka, viii+476pp.

Mondal, R.P., T.K. Dutta & B. Dhua (2013). Reporting a new site record of the breeding population of Lesser Adjutant (Leptoptilos javanicus) from Bankura District, West Bengal, India. International Journal of Current Research 6: 4441–4443.

Ohlendorf, H.M., E.E. Klaas & T.E. Kaiser (1978). Organochlorine residues and eggshell thinning in Wood Storks and Anhingas. Wilson Bulletin 90: 608–618.

Subaraj, R. & A.F.S.L. Lok (2009). Status of the Lesser Adjutant stork (Leptoptilos javanicus) in Singapore. Nature in Singapore 2: 107–113.