Berhampur, May 4: A significant number of baya weavers (Ploceus Philippinus), whose population had dwindled after the super cyclone in October, 1999, returned to Ganjam, making bird-watchers happy.

Even though there were no systematic government or private surveys on these birds prior to the super cyclone, Rushikulya Sea Turtles Protection Committee secretary Rabindra Nath Sahu said the natural calamity damaged a large number of trees where these birds had made their nests.

The voluntary organisation regularly monitors activities of the sea turtles, baya weavers and sparrows.

"We have been watching the weaver birds since 2007. In 2012, just one year before Phailin, the number of weaver birds in the district had been around 1,500. The 2013 cyclone severely affected the birds, and the number of their nests came down by 80 per cent. Last year, we had spotted 200 nests. That number has climbed to 400 this year," said Sahu.

The birds have been spotted at least in six places of the district - Lunguri village in Malagada panchayat, Borigaon in Huma panchayat, Khatiakuda and Kundaput under Palibandha panchayat, Damodarpur and Ganjam railway station in the Ganjam notified area council.

"At Lunguri village, there are 40 nests in a palm tree and 31 nests in another, both near a pond. Near Ganjam railway station, there are more than 100 nests in two trees, including four coconut trees and three dates trees, near a canal," Sahu said.

"It is a good sign that more baya weaver birds are preferring to stay here," said divisional forest officer (Berhampur) Ashish Kumar Behera.

"The forest department has recently initiated steps to take new conservation strategies in Ganjam to preserve the baya weaver birds apart from black bucks, peacocks and other species."

Behera said wetlands, swamps and tall grasses are conducive for weaver birds' habitation. But, the population pressure on land has led to their decline. These birds have adopted to some non-traditional trees now.

"Weaver birds are mostly found in South and South-East Asia. They live in grasslands, cultivated areas and shrubs. They are generally found near fresh or brackish water bodies. These birds are small in size. Non-breeding males and females look alike. They are known for their elaborately woven nests," he said.

According to forest officials, the birds breed during monsoon when the male birds build nests to attract the female ones. They prefer to live in a colony with several nests in a single tree, and it is not uncommon to find 20 or 30 nests in a single tree. The males take around 20 days to build a nest and each strip can be between 20 and 60cm in length.

A female bird first inspects the under-construction nest before signalling her approval to the male. Once a female chooses to mate with him, he might finish the nest. But often, the female completes the nest.

When the female lays eggs and is preoccupied with incubating the eggs, the male abandons her and immediately uses his other half-finished nests to woo a new female. Most males mate with two females, sometimes three.

The males defend his nests from other males. The females are left to incubate the eggs and raise the brood on their own. Each bird lays three or four white eggs and the chicks are fed insects.

Salim Ali in his Book of Indian Birds writes: "The nesting season of this bird is from May to September coincident with the southwest monsoon and paddy cultivation. The nest is a swinging retort-shaped structure with long vertical entrance tube, completely woven out of strips of paddy leaves and ruff-edged grasses suspended in clusters. Blobs of mud are stocked inside the dome near the egg chamber."

Each bird lays "two to four pure white eggs in a season. The male alone will nest. The female alone incubates. Each male has several nests and females at the same time. Hence it is a polygamous bird."

The book adds: "When the male finishes half the nest, the female inspects the nest and if she approves it, they start mating and thereafter, the male finishes the nest and invites the female to occupy it and lay eggs. After that, the male starts building another nest and invites another female and the process is repeated five or six times in one season."

"Sometimes, glow worms are also found inside the nest - probably to light the egg chamber," Ali says.