| Turacos and relatives | |
|---|---|
| Guinea Turaco, Tauraco persa at Birds of Eden aviary, South Africa | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Subclass: | Neornithes |
| Infraclass: | Neognathae |
| Superorder: | Neoaves |
| Order: | Cuculiformes (and see text) |
| Family: | Musophagidae |
| Genera | |
| Synonyms | |
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Apopempsidae |
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The turacos make up the bird family Musophagidae (literally "banana-eaters"), which includes plantain-eaters and go-away-birds. In southern Africa both turacos and go-away-birds are commonly known as louries. They are semi-zygodactylous - the fourth (outer) toe can be switched back and forth. The second and third toes, which always point forward, are conjoined in some species. Musophagids often have prominent crests and long tails; the turacos are noted for peculiar and unique pigments giving them their bright green and red feathers.
Traditionally, this group has been allied with the cuckoos in the order Cuculiformes, but the Sibley-Ahlquist taxonomy raises this group to a full order Musophagiformes. They have been proposed to link the Hoatzin to the other living birds[1] but this was later disputed.[2]
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Musophagids are medium-sized arboreal birds endemic to sub-Saharan Africa, where they live in forests, woodland and savanna. Their flight is weak, but they run quickly through the tree canopy. They feed mostly on fruits and to a lesser extent on leaves, buds, and flowers, occasionally taking small insects, snails, and slugs. Contrary to what the names might suggest, they generally do not eat bananas or plantains and indeed wild-living musophagids do not seem to use Musa as food at all.
They are gregarious birds that do not migrate. Many species are noisy, with the go-away-birds being especially noted for their piercing alarm calls, which alert other fauna to the presence of predators or hunters; their common name refers to this. Musophagids build large stick nests in trees, and lay 2 or 3 eggs. The young are born with thick down and open, or nearly-open, eyes.[3]
The Go-away-birds and plantain-eaters are mainly grey and white. The turacos on the other hand are brightly coloured birds, usually blue, green or purple. The green color in turacos comes from turacoverdin, the only true green pigment in birds known to date. Other "greens" in bird colors result from a yellow pigment such as some carotenoid, combined with the prismatic physical structure of the feather itself which scatters the light in a particular way and giving a blue color. Turaco wings contain the red pigment turacin, unlike in other birds where red color is due to carotenoids. Both pigments are derived from porphyrins and only known from the Musophagidae at present, but especially the little-researched turacoverdin might have relatives in other birds.
The fossil genus Veflintornis is known from the Middle Miocene of Grive-Saint-Alban (France). It was established as Apopempsis by Pierce Brodkorb in 1971, but this is preoccupied by Schenkling's 1903 use of the name for some beetles. "Apopempsis" africanus (Early Miocene of Kenya) might also belong there.[4]
Further fossil material of putative musophagids was found in Egypt as well as in Late Oligocene deposits at Gaimersheim (Germany) and Middle Miocene deposits at Grive-Saint-Alban[5] and Vieux-Collonges (both France).[4] While it is not entirely certain that these fossils indeed are of turacos, it nonetheless appears as if the family evolved in the Oligocene of central Europe or perhaps northern Africa, and later on shifted its distribution southwards. The climate of those European regions during the late Paleogene was not too dissimilar to that of (sub)tropical Africa today; the Saharan desert was not yet present and the distance across the Mediterranean was not much more than what it is today. Thus such a move south may well have been a very slow and gradual shifting of a large and continuous range.
The Early Eocene Promusophaga was initially believed to be the oldest record of the turacos; it was eventually reconsidered a distant relative of the ostrich and is now in the ratite family Lithornithidae. Filholornis from the Late Eocene or Early Oligocene of France is occasionally considered a musophagid, but its relationships have always been disputed. It is not often considered a turaco anymore in more recent times and has been synonymized with the presumed gruiform Talantatos, though it is not certain whether this will become widely accepted.[4]
The living species of Musophagidae, arranged in taxonomic sequence, are:
FAMILY MUSOPHAGIDAE
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