Guwahati, Dec. 13: Researchers working on greater adjutant stork ( Leptoptilos dubius) have revealed that a nesting colony of 171 greater adjutant storks at Dadara-Pasariya-Singimari villages in Kamrup district is the biggest in the world.

Assam represents one of the largest nesting colonies of this species.

The revelation has been made by wildlife biologist of NGO, Aaranyak, Purnima Devi Barman and D.K. Sharma of zoology department of Gauhati University in an article " Largest breeding colony of Greater Adjutant, Leptoptilos dubius, in Dadara-Pasariya-Singimari Villages in Assam" in the latest issue of Zoo's Print, a magazine of Zoo Outreach Organisation.

"We recorded the following numbers of successful nests (with hatchlings): 95 in 2009-2010, 90 in 2010-2011, 114 in 2011-2012, 152 in 2012-2013, 128 in 2013-2014 and 171 in 2014-15. "This nesting colony is now the biggest greater adjutant nesting colony in the world. Such a large number of nests have not been recorded in other nesting colonies in India or in Cambodia," said Sharma. Dadara is 25km from Guwahati.

Greater Adjutant stork is a globally endangered bird breeding in Assam and Bihar and Prek Toal Bird Sanctuary and Northern Plains in Cambodia.

The bird's habitat has been greatly impacted by human development and a number of historical colonies have decreased in numbers or disappeared, heightening the importance of monitoring and conservation efforts to protect this species and its habitat.

Its population in Assam is estimated at about 600-700 birds and the state is considered to be its last stronghold. In Bihar, about 150 birds were recorded in few breeding colonies and the current estimated population in Cambodia is about 200 birds.

Barman, who has been working on the conservation of this bird, said: "Last year, for the first time in our study, hatching success of four chicks in at least four nests in this breeding colony was recorded. Because of heightened awareness and motivation in the villages in last five years, not a single nesting tree has been cut down in the Dadara-Pasariya-Singimari nesting colony. The villagers have now developed a feeling of ownership for the bird and have become its protectors," she said.

Nest-building behaviour, clutch size, incubation, hatching success, population recruitment, diurnal feeding behaviour and parenting have been recorded in this breeding colony. The breeding season of storks starts in August and ends in April.The bird mainly prefers Indian devil tree, kadamba, jack tree, simul or cotton tree for nesting.

"Participation of communities in the conservation of the bird is a must for its survival," Barman added.

In Assam, this colonial nesting bird breeds in very few traditional nesting colonies. This bird forms its breeding colony in tall trees within densely populated villages and distributed within one or two kilometres of the periphery of the village boundary.