The African barbets are birds in the familyLybiidae. They were usually united with their New World and Asian relatives in the Capitonidae for quite some time, but this has been confirmed to be limited to the main New World lineage. There are 43species ranging from the type genusLybius of forest interior to the tinkerbirds of forest and scrubland. They are found throughout sub-Saharan Africa, with the exception of the far south-west of South Africa. The African terrestrial barbets, Trachyphoninae, range from the southern Sahara to South Africa. Members of one genus, Trachyphonus, they are the most open-country species of barbets. The subfamily Lybiinae contains the African arboreal barbets. There are 37 species of Lybiinae in 6 genera.
Description and ecology
Most African barbets are about long, plump-looking, with large heads, and their heavy bill is fringed with bristles; the tinkerbirds are smaller, ranging down to the red-rumped tinkerbird at and. They are mainly solitary birds, eating insects and fruit. Figs and numerous other species of fruiting tree and bush are visited, an individual barbet may feed on as many as 60 different species in its range. They will also visitplantations and take cultivated fruit and vegetables. Fruit is eaten whole and indigestible material such as seed pits regurgitated later. Regurgitation does not usually happen in the nest, although tinkerbirds do place sticky mistletoe seeds around the entrances of their nests, possibly to deter predators. As the other barbets, they are thought to be important agents in seed dispersal in tropical forests. As well as taking fruit, African barbets also take arthropod prey, gleaned from the branches and trunks of trees. A wide range of insects are taken, including ants, cicadas, dragonflies, crickets, locusts, beetles, moths and mantids. Scorpions and centipedes are also taken, and a few species will take small vertebrates such as lizards, frogs and geckos. The precise nesting details of many African barbets are not yet known, although peculiarly among the Piciformes, some sociable species will nest in riverbanks or termite nests. Like many members of their order, Piciformes, their nests are in holes bored into a tree, and they usually lay between 2 and 4 eggs, incubated for 13–15 days. Nesting duties are shared by both parents. There has been generally little interference by humans. Some of the species which require primary woodland are declining due to deforestation, occasionally to the benefit of close relatives. For example, the loss of highland woods in Kenya has seen the moustached tinkerbird almost disappear and the red-fronted tinkerbird expand its range.
Systematics
Subfamily Lybiinae
Genus Gymnobucco
Genus Stactolaema
Genus Pogoniulus – tinkerbirds
Genus Buccanodon – yellow-spotted barbets
Genus Tricholaema
Genus Lybius
Subfamily Trachyphoninae
Genus Trachyphonus
It is not entirely resolved whether the Early to Middle Miocene genus Capitonides from Europebelongs to this family or the Asian barbets. Indeed, given that the prehistoric birds somewhat resembled a primitive toucan, they might occupy a more basal position among the barbet-toucan clade altogether. On the other hand, they show some similarities to Trachyphonus in particular and have even been placed into this genus, but this move is not widely accepted. "CMC 152", a distalcarpometacarpus similar to that of barbets and found at the MiddleMiocene locality of Grive-Saint-Alban was considered to differ from Capitonides in the initial description, being closer to extant barbets. This fossil is sometimes lumped into Trachyphonus too; in this case it may have more merit. Supposed fossil remains of Late MiocenePogoniulus were found at Kohfidisch but are not yet thoroughly studied. It is not clear whether they belong to the extant genus but given the late date this may well be so.
