About Cinnyris asiaticus (Latham, 1790)
The purple sunbird (Cinnyris asiaticus) shows strong sexual dimorphism, and has a relatively short bill and a short, dark, square-ended tail. All individuals are less than 10 cm (3.9 in) long, with a down-curved bill and brush-tipped tubular tongues adapted to help feed on nectar. Breeding males have glossy metallic bluish to purplish black upperparts, with dark brown wings, and underparts matching the purplish black of the upperparts. They also have a bright blue patch on the shoulder, and a maroon sheen on the collar feathers that is most visible during the breeding season. Breeding males sometimes display their yellow pectoral tufts, and can be confused with the syntopic Loten's sunbird, which differs by having a longer bill and a distinctive broad maroon breast band. Non-breeding males may show a central black streak on yellow underparts. Females have olive-brown upperparts and a yellowish underside, with a pale supercilium extending beyond the eye, a darkish eye stripe, and yellow throat and breast that fade to pale closer to the vent. Both males and females have white-tipped outer tail feathers. Young purple sunbirds have plumage identical to that of females, but young males develop black feathers as they reach adulthood. Purple sunbirds are typically seen in pairs or small groups, and can gather in aggregations in gardens that have suitable flowers; groups of up to 40 to 50 individuals have occasionally been recorded. They feed mainly on nectar, but also consume fruits and insects. The species is widely distributed from West Asia through the Indian subcontinent and into Southeast Asia. Most populations are resident and do not move long distances, though local movements have been recorded, particularly in the drier parts of northwestern India and Pakistan, where they reportedly arrive in large numbers before summer. They inhabit thin forest and garden landscapes, including those in dense urban areas. Three subspecies are currently recognized. The nominate subspecies occurs in India east of the desert region and south of the Himalayas, extending to western and southern India and Sri Lanka. It mainly lives on the plains, but can be found at elevations up to 2,400 m (7,900 ft) in southern India and up to 1,700 m (5,600 ft) in the Himalayas. The subspecies brevirostris occurs in the dry zone from the Arabian Peninsula through Iran, Afghanistan, and Pakistan, reaching into the dry zone of Rajasthan and Gujarat; these individuals may winter south near Goa, and have a slight green tinge in their yellow pectoral tufts. The subspecies intermedius ranges from the border of Orissa and Andhra Pradesh northwards into Bangladesh, Myanmar, and Indochina. The overall movement patterns of purple sunbirds are not well understood; one male ringed in Bharatpur was recovered 350 km (220 mi) north in Dehra Dun. Purple sunbirds are very vocal, and will call and join together to mob owls and other predators. Their song consists of a rapid rattle followed by ringing, metallic notes, and other common calls include "chwit" or "chwing!" notes. While feeding, they flick their wings. They rarely hover at flowers, and usually perch to forage for nectar. They act as important pollinators for several plant species, including Butea monosperma, Acacia, Woodfordia, and Dendrophthoe, but will sometimes steal nectar by slitting the base of flowers such as Hamelia patens. They also feed on small berries including those of Salvadora persica and cultivated grapes, and sometimes catch insects through flycatching. During courtship displays, the male raises his head, fans his tail, flutters with partly open wings that expose his pectoral tufts, and sings in front of the female. The breeding nest is a pouch constructed from cobwebs, thin vegetation strips, lichens, and bark, with an entrance hole on the side that is usually shaded by an overhanging projection. Almost all nest construction is done by the female. Nest material is not woven, and is held together almost entirely by cobwebs; nest building takes between five and ten days. The bird expands the inner cavity by opening its wing and turning around inside the nest. In Sri Lanka and southern India, purple sunbirds sometimes build their nests by modifying and lining existing cobweb structures built by the colonial social spider Stegodyphus sarasinorum (Eresidae). Nests are usually suspended from a low branch, often of thorny plants, but may also be built close to human habitations, attached to wires or other man-made objects, and even placed indoors in an unused toilet. Clutches usually contain two eggs. Only the female incubates the eggs, which hatch after 15 to 17 days. Males help feed the chicks, though females contribute more, making more feeding trips as the chicks get older. Purple sunbirds have been recorded living for nearly 22 years in captivity.
