Tailorbird (Orthotomus sutorius)

The Common Tailorbird (Orthotomus sutorius) is a songbird found across tropical Asia. Popular for its nest made of leaves "sewn" together and immortalized by Rudyard Kipling in his Jungle Book, it is a common resident in urban gardens. Although shy birds that are usually hidden within vegetation, their loud calls are familiar and give away their presence. They are distinctive in having a greenish upper body plumage, long upright tail and the rust coloured forehead and crown.

These 13-cm-long warblers are brightly coloured, with bright green upperparts and whitish underparts. They have short rounded wings, a long tail, strong legs and a sharp bill with curved tip to the upper mandible. They are wren-like with a long upright tail that is often moved around. The crown is rufous and the upperparts are predominantly olive green. The underside is creamy white. The sexes are identical, except that the male has long central tail feathers in the breeding season. (The reliability of sexing of specimens in determining this difference has been questioned by Hugh Whistler.^[2]) Young birds are duller.^[3]When calling the dark patches on the sides of the neck become visible.^[4] These are due to the dark pigmented and bare skin that are present in both sexes and sometimes give the appearance of a dark gorget.^[5]

This passerine bird is typically found in open farmland, scrub, forest edges and gardens. Tailorbirds get their name from the way their nest is constructed. The edges of a large leaf are pierced and sewn together with plant fibre or spider silk to make a cradle in which the actual nest is built.

Calls of guzuratus from southern India

Like most warblers, the Common Tailorbird is insectivorous. The song is a loud cheeup-cheeup-cheeup with variations across the populations. The disyllabic calls are repeated often.^[3]

Behaviour and ecology

Tailorbirds are found in singly or in pairs, usually low in the undergrowth or trees sometimes hopping on the ground. They forage for insets and have been known to feed on a range of beetles and bugs. They are attracted to insects at flowers and are known to favour the inflorescenses of mango. They are known to visit the flowers of Bombak, Salmalia and other large flowers for nectar and get covered on the head and throat with pollen, giving them a golden-headed appearance.^[5]dia

The breeding season is March to December peaking from May to August. In Sri Lanka the main breeding season is March to May and August to September.^[3] Although the name is derived from the nest, the nest is not unique and similar nests are also found in many Prinia warblers

The nest is a deep, soft cup lined with soft materials and is placed in thick foliage and the leaves used to hold the nest have the upper surfaces outwards so that the nest is difficult to spot. The punctures made on the edge of the leaves are minute and do not cause browning of the leaves, further aiding camouflage. The nest lining of a nest in Sri Lanka that was studied by Casey Wood was found to be lined with lint from Euphorbia, Ceiba pentandra and Bombax malabaricum species. Jerdon had noted that the bird made knots, however no knots have been described by subsequent observers. Wood classified the processes used by the tailorbird in nest as sewing, rivetting, lacing and matting. In some cases the nest is made from a single large leaf; the margins of which are rivetted together. Sometimes the fibres from one rivet are extended into an adjoining puncture and appearing more like sewing.^[7] The stitch is made by piercing two leaves and drawing fibre through them. The fibres fluff out on the outside and in effect they are more like rivets.^[10] There are many variations in the nest and some may altogether lack the cradle of leaves. One observer noted that the birds did not utilize cotton that was made available^[11] while another observer, Edward Hamilton Aitken, was able to induce them to use artificially supplied cotton.^[12] The usual clutch is three eggs.^[13][14] It is said that only the female stitches the leaves of the nest. The incubation period is about 12 days. Both male and female feed the young. Mortality of eggs and chicks are high due to predation by rodents, cats, crow-pheasants, lizards and other predators.^[5] The incubation period is about 12–14 days and the young birds fledge in about 14 days. The female alone incubates according to some sources while others suggest that both sexes incubate but both parents take part in feeding and sanitation.^[15] The males are said to feed the incubating female.^[5] An unusual case of a pair of tailorbirds adopting chicks in an artificially translocated nest belong to a different pair has been recorded.^[16] Nests are sometimes parasitized by the Plaintive Cuckoo(Cacomantis merulinus).^[5]

The birds roost alone during the non-breeding season but may roost side-by-side during the breeding season, sometimes with the newly fledged juvenile sandwiched between the adults. The roost sites chosen are thin twigs on trees with cover above them and were often close to human habitation and lights

References

1. ^ BirdLife International (2008). Orthotomus sutorius. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 3 Oct 2009.
2. ^ Ali,Salim; Whistler,Hugh (1939). "The birds of Central India. Part I.". J. Bombay Nat. Hist. Soc. 41(1): 82–106.