Baya Weaver
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Order: Passeriformes
Family: Ploceidae

[Photo] Baya Weavers (Ploceus philippinus), pair at Kotaballappalli, Karnataka, India. Date 2006-10-06. Author: Rajeev B (http://commons.wikimedia.org/wiki/User:Rawlife).

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The Baya Weaver (Ploceus philippinus) is a weaver found across South and Southeast Asia. They inhabit grassland, cultivated areas, scrub and secondary growths usually near fresh or brackish water. They are widespread and common within their distribution area but are prone to local seasonal movements. Despite their species name, they are not found in the Philippines. Three geographical races are recognized. The race philippinus is found through much of mainland India. The race burmanicus is found eastwards into Southeast Asia. A third race travancoreensis is darker above and found in southwest India.

Description
These are sparrow sized (15 cm) and in their non-breeding plumage, both males and females resemble female house sparrows. They have a stout conical bill and a short square tail. Non-breeding males and females look alike, dark brown streaked fulvous buff above, plain (unstreaked) whitish fulvous below, eyebrows long buffy, bill is horn coloured and no mask. Breeding males have a bright yellow crown, dark brown mask, blackish brown bill, upper parts are dark brown streaked with yellow, with a yellow breast and cream buff below.

Local Names
Baya, Son-Chiri (Hindi); Sugaran (Marathi); Tempua (Malay); Sughari (Gujarati); Babui (Bengali); Parsupu pita, Gijigadu/Gijjigadu (Telugu); Gijuga (Kannada); Thukanam kuruvi (Malayalam);Thukanan-kuruvi (Tamil); Wadu-kurulla, Tatteh-kurulla, Goiyan-kurulla (Sinhala); sa-gaung-gwet, mo-sa (Myanmar); Bijra (Hoshiarpur); Suyam (Chota Nagpur).

Habits
Baya Weavers are social and gregarious birds. They forage in flocks for seeds, both on the plants and on the ground. Flocks fly in close formations, often performing complicated manouvres. They are known to glean paddy and other grain in harvested fields, and occasionally damage ripening crops and are therefore sometimes considered as serious pests. They roost in reed-beds bordering waterbodies. They depend on wild grasses such as Guinea Grass (Panicum maximum) as well as crops like paddy for both their food and nesting material. They also feed on insects. Their seasonal movements are governed by food availability.

They are occasionally known to descend to the ground and indulge in dust bathing.

Breeding
The breeding season of the Baya Weavers is during the monsoons. They nest in colonies of up to 20-30, close to the source of food, nesting material and water. The nests are often built hanging over water from palm trees and often thorny Acacias and in some cases from telephone wires. Baya Weavers are best known for their elaborately woven nests. These pendulous nests are retort shaped, with a central nesting chamber and a long vertical tube that leads to a side entrance to the chamber. The nests are woven with long strips of paddy leaves, rough grasses and long strips torn from palm fronds. Each strip can be between 20-60cm in length. A male bird is known to make up to 500 trips to complete a nest. The birds use their strong beaks to strip and collect the strands, and to weave and knot them while building their nests. Abandoned nests are sometimes used by mice and other birds such as Munias.

Histochemical changes have shown increased lipid metabolism in the crown region of male Baya during the breeding season. Lipids are known to be involved in the transport of the yellow carotenoid pigments that form the crown and are subsequently metabolized.

Breeding behavior
During the breeding season the males begin building nests. The nests are partially built when the males display to passing females by flapping their wings and calling while hanging to their nests. The call of the Baya males which is normally a sparrow-like chit-chit is followed by a long-drawn chee-ee in the breeding season. The females inspect and choose a nest before signalling their approval to a male. Once a male and a female are paired, the male goes on to complete the nest including the entrance tunnel, males are solely incharge of building the nests, though their female partners may join in giving the finishing touches. Studies have shown that nest location is more important than nest structure for the female decision making.

The males are polygynous, mating with 2 to 3 females one after another. Males build many partial nests and start attracting females. A male finishes the nest to its completion only after finding a mate, after mating the female lays about 2 to 4 white eggs and incubates them. The females are solely responsible for incubating and bringing up the brood. After mating with a female the male goes on to woo more females with its other nests. Females are known to lay their eggs in the nests of other females.

Other notes
The half built male nests of Baya weavers look like helmets with chin-straps and are called cock-swings.

A widespread local myth is that the Baya uses fireflies stuck to the nest walls with mud to light up the interior of the nest at night. However dry clay is known to be found in the nests of Baya weavers. It is said that they collect blobs of mud when wet, and stick them inside the dome near the egg-chamber. It is also said that they use lumps of dry clay inserted around the rim to stabilise the nests in strong winds.

In earlier times, the Baya Weaver was trained by street performers in India for entertainment. They were trained to fire toy cannons, string beads, pick up coins and other objects. These uses have been noted from the time of Akbar.

"The baya is like a wild sparrow but yellow. It is extremely intelligent, obedient and docile. It will take small coins from the hand and bring them to its master, and will come to a call from a long distance. Its nests are so ingeniously constructed as to defy the rivalry of clever artificers." ???????n (trans. Jarrett), iii. 122. (ca. 1590) quoted in the Hobson Jobson

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