Waxbills and Weavers
The waxbills are notable for their extraordinary diversity of plumage. Some species are relatively somberly clad in grays, browns, and white but many of them make up for their lack of bright coloration with attractive markings. The Double-bar finch, Pictorella finch, and Zebra finch all illustrate this tendency. Other species are richly colored, including the blue of cordon bleus, reds of fire finches, and green and yellow of the Green avadavat.
The most colorful of them all is, however, the Gould a finch, whose combination of green, yellow, cobalt-blue, turquoise, purple, and white give it a bizarre, and perhaps (depending on taste), beautiful appearance. This species also shows an interesting variation in head coloration: the heads of roughly 75 percent of Gould and finches in the wild are black but most of the remaining 25 percent are red. There is another so-called yellow-headed form (in reality it is orange in color), which occurs in about one in every thousand orzo wild birds.
Most waxbills are social and occur in flocks in the non-breeding season, sometimes aggregating in large mixed species groups. The behavior of individuals within flocks tends to be synchronized; they feed together, take off simultaneously, show coordinated flight movements, and perform acts, such as preening and bathing, at the same time.
Experimental work on captive birds, and recordings made from flocks living under natural conditions, have shown that both calls and visual stimuli are important in synchronizing behavior. Flight movements, for instance, are coordinated, at least in part, by so-called “flight calls” which are given by birds taking off and in flight. The acts of preening and flying down from perching places to the ground to forage are, on the other hand, synchronized by the sight of other birds performing these acts.
There is a greater emphasis on coordination by calls in forest-inhabiting species, in which members of flocks may have difficulty in maintaining visual contact with one another, than in species that inhabit the open country.
Pair bonds are strong in most species and members of pairs keep together during the breeding season. They indulge in gestures, such as clumping (perching in contact) and preening one another, which probably serve to maintain and strengthen bonds between them. Breeding occurs in the wet season, when the food on which the nestlings are reared, mostly seeding grasses and insects, is abundant.
Predators, including hawks, snakes, and small mammals, take a heavy toll on eggs and nestlings and breed-in success is often poor. Records of several African species show that only 18-3 percent of the eggs lay survive to produce fledglings; most of the rest are destroyed by predators. Nestlings possess conspicuous marks on the palate and tongue which are revealed whenever they gape for food. There are additional luminous spots at the base of the bill in some species. These markings probably stimulate parents to feed their young and also help them to locate the nestling’s mouths in the semi-darkness of the thinnest.
Waxbills adapt well to life in captivity and have become popular cage birds. Two species in particular. The Bengalese finch and the Zebra finch are now thoroughly domesticated and are available in several different color varieties. Together with other species, they are kept by aviculturists throughout the world. Unfortunately. The demand for most African and Asian finches is met by trapping them in the wild. Dealers in these two continents export enormous numbers of finches worldwide. It has been estimated, for example, that Europe alone imports 71 million birds a year, a very large proportion of which are wild-caught wax bills.
The extent to which the trade is depleting natural populations is unknown, but other aspects of it, such as severe mortality of birds in transit, caused by overcrowding or insufficient food, are undesirable. It is questionable whether the trade is necessary at all. Aviculturists faced with the non-availability of certain species from the wild have been highly successful in breeding and maintaining captive strains.
The Australian Government’s ban on the import and export of fauna in the 196os, for example, meant that new stocks of African and Asian species were no longer available to Australian aviculturists, and of Australian finches to aviculturists in other parts of the world. Serious bird breeders in Australia have nevertheless established strains of many non-native species, including cordon bleu, fire finches, and waxbills, while European aviculturists still keep and breed viable stocks of at least thirteen of the Australian species.
The Weaver family can be divided into four subfamilies. Most true weavers are thick-set seed-eating birds with strong short bills and many can construct elaborately woven nests. Some forest species have less robust bills and are mainly insectivorous.
The majority of the true weavers are confined to Africa and its neighboring islands and can be separated into two groups. The first group is exclusively tree dwellers, nearly all with bright yellow or red plumage, and build elaborately suspended nests that are tough, with the entrance on the underside, or protected by a tunnel. The tunnel may be as much as 6ocm (2ft) longhand the nests are often built at the tips of twigs or palm fronds, and often sited near water. In a nesting colony, the tree top is often fill-led with their nests, slung on branches very close together. The Village weaver may build several nests, advertising each to any interested female. He hangs upside down at the entrance, located at the bottom of the thinnest, with many wings flapping and chattering.
The second group comprises the foodies and bishops, which build globular nests and except for the foodies, often place them in ingress or herbage instead of suspending them in trees. Territorialism is highly developed in these birds and in a grassy area of a floodplain several species may have their territories. The Yellow bishop can have several females nesting in his territory so he spends a great deal of his time patrolling his boundaries and giving aggressive calls.
Among the three species of ditches, there-billed quelled has been known from its earliest recorded history as a menace to crops of small grain. This species is completely colonial in its habits and is often found in concentrations of over a million birds. Large-scale efforts at control, coupled with research, began in Sudan in 1946, and by 1953 had become necessary in other territories, but despite immense slaughter, the plague continues.
There are also two species in separate genera outside the two main groups, the Grosbeak weaver, which has a very heavy bill and weaves a superior globular nest of extremely fine fibers, and the Cuckoo weaver which is a small yellow bird that parasitizes grass-warblers.
The viding weavers and whydahs parasitize species of waxbills. The young of each host species carry distinctive color sand markings on their palates, which serve to release the feeding behavior of the parents. Chicks of the parasitic wh. yeah, mimic these markings with extraordinary accuracy.
The buffalo weavers inhabit the drier areas of Africa, feeding on the ground in the manner of starlings. They have a mixed diet and build large untidy nests of thorny twigs, which are highly protective.
The sparrows tend to associate with man, and at least eight of the species regularly nest in the eaves of inhabited buildings. The House sparrow is the most persistent of all and is only rarely found breeding away from the man. The Tree sparrow fills the same niche in the eastern parts obits range, where the House sparrow is absent. Despite the close association with man, House sparrows are extremely wary birds and not easily kept in captivity. Many of the sparrows are gregarious and breed in colonies, although the nests do not form communal structures as do those of some other species of weavers.
The Rock sparrows are mainly gray and brown birds with a yellow patch on the throat. However, the African species, including the Yellow-throated sparrow, which extends to India, are birds more of trees than rocks. The remaining two species, the Rock sparrow and the Pale rock spar-row are more typical “rock” sparrows. As they typically nest in holes in rocks or walls.
The snow finches spend their lives almost entirely on the ground and are among the highest-nesting of living birds. Since they occur from 1800 to 4.600m. They are gregarious in winter. Forming flocks, which may descend to lower altitudes in severe weather? Although they do not leave the mountains altogether.
See more: FEEDING A BIRD