In recent years the display behavior of weaverfinches has been studied with particular intensity. The bond between members of a pair, and sometimes among members of a small flock, is usually strong. Unlike in many groups of birds, male weaverfinches do not feed the female as part of a courtship ritual. In most species the male has a "display dance" in which it sings and either hops towards the female or performs characteristic bows or stretching movements while hopping about in front of the female. Many avadavats (Amandava spp.) and some Australian grassfinches hold a feather or a grass stalk in the bill during this display, apparently as a nest symbol. The

Bill morphology can often give insight into the diet of a species. Those with slender bills typically consume more insects in their diet, while those with conical bills eat primarily a seed-based diet. The relative size of the bill is often directly proportional to the size of the food that the species can consume. These species illustrate the range of bill shapes and sizes represented within the family Estrildidae: 1. Common waxbill (Estrilda astrild); 2. Red-fronted flowerpecker weaver-finch (Parmoptila rubrifrons); 3. White-breasted negro-finch (Nigrita fusconota); 4. Double barred finch (Poephila bichenovii); 5. Green-winged pytilia (Pytilia melba); 6. Java sparrow (Padda oryzivora); 7. Crimson seedcracker (Pyrenestes sanguineus). (Illustration by Joseph E. Trumpey)

female weaverfinch's way of indicating readiness for mating is unique among songbirds. She cowers on a branch and trembles her tail, which is held vertically while the wings are kept still. In contrast, other songbird females tremble their wings and keep the tail quite still.

The song of weaverfinches is often soft and sometimes inaudible to human ears. This may, in part, be due to the fact that weaverfinches do not use songs to indicate aggression or territoriality, and therefore do not need their song to be heard by neighbors. An often unmusical and short song is uttered just loud enough for a nearby female to hear as part of the male's courtship. Unlike other vocalizations, the song is not instinctual. Instead, it is learned during a very narrow window during development of the fledgling (25 to 35 days of age for the zebra finch). Captive birds raised by a different species often learn the song of the male foster parent, but not the other calls. However, they can learn the meaning of the foster parents' calls and will often respond with the corresponding call from their own repertoire.

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