2. The estrildid finches are small passerinebirds of the Old World tropics and Australasia. They can be classified as the familyEstrildidae (weaver-finch), or as a sub-group within the family Passeridae, which also includes the true sparrows.[1] They are gregarious and often colonial seed-eaters with short, thick, but pointed bills. They are all similar in structure and habits, but vary widely in plumage colours and pattern. All the estrildids build large domed nests and lay 5–10 white eggs. Many species build roost nests. Some of the fire-finches and pytilias are hosts to the brood-parasiticindigobirds and whydahs respectively.
3. Most are sensitive to cold and require a warm, usually tropical, habitat, although a few have adapted to the cooler climates of southern Australia. The smallest species of the family is the Fernando Po Oliveback (Nesocharisshelleyi) at a mere 8.3 cm (3.3 inches), although the lightest species is the Black-rumped Waxbill (Estrilda troglodytes) at 6 g. The largest species is the Java Sparrow (Paddaoryzivora), at 17 cm (6.7 inches) and 25 g.
![The estrildid finches are small passerinebirds of the Old World tropics and Australasia. They can be classified as the familyEstrildidae (weaver-finch), or as a sub-group within the family Passeridae, which also includes the true sparrows.[1] They are gregarious and often colonial seed-eaters with short, thick, but pointed bills. They are all similar in structure and habits, but vary widely in plumage colours and pattern. All the estrildids build large domed nests and lay 5–10 white eggs. Many species build roost nests. Some of the fire-finches and pytilias are hosts to the brood-parasiticindigobirds and whydahs respectively.](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)