Emu Emu Society
Journal of BirdLife Australia

Factors affecting formation of flocks of unusual size and composition in Black-necked Storks (Ephippiorhynchus asiaticus) in Australia and India

K. S. Gopi Sundar A , Greg P. Clancy B D and Nita Shah C

A Indian Cranes and Wetlands Working Group, c/o International Crane Foundation, E-11376, Shady Lane Road, Baraboo, WI, 53913, USA, and Wildlife Protection Society of India, S-25, Panchsheel Park, New Delhi, 110017, India. Email: gopi@savingcranes.org

B Department of Zoology, School of Environmental Sciences and Natural Resources Management, University of New England, National Marine Science Centre, c/o PO Box 63, Coutts Crossing NSW, 2460, Australia.

C Vulture Advocacy Programme, Bombay Natural History Society, A-309, Yamuna Apartments, Alakananda, New Delhi, 110019, India.

D Corresponding author. Email: gclancy@tpg.com.au

Emu 106(3) 253-258 http://dx.doi.org/10.1071/MU05014
Submitted: 21 March 2005  Accepted: 3 May 2006   Published: 18 August 2006


The Black-necked Stork (Ephippiorhynchus asiaticus) usually occurs singly, in pairs or in family groups, and only very rarely in flocks. We describe records of flocks of this species in the Australian and Indian subspecies and discuss the possible reasons for their occurrence. Records of flocks were fewer from India, but flock-sizes were significantly larger. Factors related to flock formation, such as season, habitat quality and water availability, differed between Australia and India. Flocks occurred predominantly in autumn in Australia, whereas there was no relationship between season and flocking in India. Flock-sizes did not differ seasonally for either subspecies or between subspecies. Flocks were composed either of adults only or combinations of young birds and adults. In Australia, occurrence of different types of flocks was not affected by season or habitat. A combination of season and local habitat conditions appear to be affecting formation of flocks in this species.


Ali S., and Ripley S. D. (1978). ‘Handbook of the Birds of India and Pakistan. Volume 1. Divers to Hawks.’ 2nd Edn. (Oxford University Press: New Delhi.)

BirdLife International. (2001). ‘Threatened Birds of Asia. The Birdlife International Red Data Book.’ (BirdLife International: Cambridge, UK.)

Dave S. (2004). Ecological study on the piscivorous birds of the semi-arid area. Ph.D. Thesis, Saurashtra University, Rajkot, India.

Elliott A. (1992). Family Ciconiidae (Storks). In ‘Handbook of the Birds of the World. Vol. 1. Ostrich to Ducks’. (Eds J. del Hoyo, A. Elliott and J. Sargatal.) pp. 436–465. (Lynx Edicions: Barcelona.)

Frederick P. C. Sandoval J. C. Luthin C. Spalding M. 1997 The importance of the Caribbean coastal wetlands of Nicaragua and Honduras to central American populations of waterbirds and Jabiru storks (Jabiru mycteria). Journal of Field Ornithology 68 287 295.

Ganguly U. (1975). ‘A Guide to the Birds of the Delhi Area.’ (Indian Council of Agricultural Research: New Delhi.)

Garnett S. Bredl R. 1985 Birds in the vicinity of Edwards River Settlement. Sunbird 15 6 40

González J. A. 1997 Seasonal variation in the foraging ecology of the wood stork in the southern Llanos of Venezuela. Condor 99 671 680

Hancock J. A., Kushlan J. A., and Kahl M. P. (1992). ‘Storks, Ibises and Spoonbills of the World.’ (Academic Press: London.)

Hutson H. P. W. (1954). ‘The Birds About Delhi.’ (Delhi Birdwatching Society: New Delhi.)

Ishtiaq F. Rahmani A. R. Javed S. Coulter M. C. 2004 Nest-site characteristics of Black-necked Storks (Ephippiorhynchus asiaticus) and White-necked Stork (Ciconia episcopus) in Keoladeo National Park, Bharatpur, India. Journal of the Bombay Natural History Society 101 90 95

Kahl M. P. 1971 Food and feeding behaviour of the Openbill Stork. Journal für Ornithologie 112 21 35

Maheshwaran G. Rahmani A. R. 2001 Effects of water level changes and wading bird abundance on the foraging behaviour of Black-necked Storks Ephippiorhynchus asiaticus in Dudwa National Park, India. Journal of Biosciences 26 373 382

Maheswaran G. Rahmani A. R. 2002 Foraging behaviour and feeding success of the Black-necked Stork Ephippiorhynchus asiaticus in Dudwa National Park, Uttar Pradesh, India. Journal of Zoology (London) 258 189 195

Marchant S., and Higgins P. J. (Eds) (1990). ‘Handbook of Australian, New Zealand and Antarctic Birds. Vol. 1. Ratities to Ducks, Part B: Australian Pelicans to Ducks.’ (Oxford University Press: Melbourne.)

Math-Soft (1998–99). ‘S-PLUS® 2000 Guide to Statistics.’ (Data Analysis Products Division, MathSoft: Seattle.)

Morris A. K. 2001 New South Wales Annual Bird Report for 1998. Australian Birds 33 101 167

Morton S. R. Brennan K. G. Armstrong M. D. 1993 Distribution and abundance of Brolgas and Black-necked Storks in the Alligator River region, Northern Territory. Emu 93 88 92

Rahmani A. R. 1989 Status of the Blacknecked Stork Ephippiorhynchus asiaticus in the Indian subcontinent. Forktail 5 99 110

Sundar K. S. G. 1999 Black-necked storks, Sarus Cranes and Drongo-cuckoos. Newsletter for Birdwatchers 39 5 Sept.–Oct. 71 72

Sundar K. S. G. 2003 Notes on the breeding biology of Black-necked Storks Ephippiorhynchus asiaticus in Etawah and Mainpuri districts, Uttar Pradesh, India. Forktail 19 15 20

Sundar K. S. G. 2004 Group size and habitat use by Black-necked Storks Ephippiorhynchus asiaticus in an agriculture dominated landscape in Uttar Pradesh, India. Bird Conservation International 14 323 334

Sundar K. S. G. 2005 Effectiveness of road transects and wetland visits for surveying Black-necked Storks Ephippiorhynchus asiaticus and Sarus Cranes Grus antigone in India. Forktail 21 27 32

Sundar K. S. G. Deomurari A. Bhatia Y. Narayanan S. P. in press Records of Black-necked Storks Ephippiorhynchus asiaticus breeding pairs fledging four chicks. Forktail

Export Citation Cited By (1)