Aldabra Fody

The Aldabra fody's bill is markedly long and heavy, a distinctive characteristic. The female is similar to a sparrow, but more yellow, with dark streaks and a more powerful bill. The breeding plumage of the male is orange-scarlet on the head and breast, with yellow on the back and body, sides and flanks imbued with olive-gray, a sulfur-yellow belly, yellowish white tips on the median covert feathers, and an orange rump. An article published in the Bulletin of the African Bird Club, a conservationist journal, described the males of the species as the "most attractive of all fodies". Immature birds are similar to the female. All plumages contain yellow tones, and all are more yellow than the related Comoros and Madagascar fodies, especially on the underparts.

Voice. There were no published recordings of the Aldabra fody's vocalizations as of 2013, but they have been well-described. There are a great variety, with many based on high-pitched and metallic two-eet, twee, or tee calls. They produce a trilling song sequence consisting of a variety of notes, described by one study as tsee-oo tsee-oo tsee-oo fsssssss looklooklooklooklook. Males generate a nasal "fizzing" noise associated with territorial defense, suggested by one ornithological encyclopedia to correspond to the fsssssss noise reported in the study. …

The Aldabra fody is endemic to Aldabra, an atoll located about 400 kilometres (250 mi) northwest of Madagascar, belonging to Seychelles. The species is widespread on Aldabra, found on all main islands, as well as smaller islets of the lagoon. The atoll, which makes up one third of the total land of Seychelles, is protected by the government as a nature reserve. "Cardinals" reported on Astove and possibly Cosmoledo in the 19th century may have been the Aldabra fody, but there is no proof of this. The Aldabra fody can be found in scrub, Cocos nucifera groves, or Casuarina woodland. Their territories may be as little as 840 square metres (1,000 yd2) in groves of large trees, which could indicate a possible forest ancestry, although there are no forests on Aldabra.

Adult males spend most of the year defending and maintaining nesting territories. They are strongly territorial, with a characteristic threat display consisting of drooping the wings and tail while puffing out the feathers of the head, breast, and rump. Intruders are challenged with a variety of calls; this may occur with a female, but upon recognition, the calls become a series of high whistles, uttered by one or both. The male then raises its wings above its back, and, if accepted, mounts and copulates with the female, wings remaining raised. Copulation has been observed in November and December. Nesting has been reported in November, December, and January, probably extending to February or March. The birds prefer to nest in coconut palms and Casuarina trees, neither of which are native to Aldabra. This may be a response to predation by the introduced Rattus rattus. Nests are large, open on the side, and partially domed. They are made of small twigs, weed stems, and coarse grasses, lined with finer grasses. The eggs, which are laid in clutches variously reported as containing 2–4 eggs, are pale glaucous green (approaching blue), unspotted, and elongate ovate in shape, with thin, glossy shells. In size, they are 2.05 centimetres (0.81 in) × 1.4 centimetres (0.55 in) on average.