Lybiidae

Description and ecology

Most African barbets are about 20–25 cm (7.9–9.8 in) 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 (Pogoniulus atroflavus) at 7 g (0.25 oz) and 9 cm (3.5 in).

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 visit plantations and take cultivated fruit and vegetables. Fruit is eaten whole and indigestible material such as seed pits regurgitated later (often before singing). Regurgitation does not usually happen in the nest (as happens with toucans), although tinkerbirds do place sticky mistletoe seeds around the entrances of their nests, possibly to deter predators. Like 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 (except for the yellow-breasted barbet which lays up to 6), 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

Subfamily Trachyphoninae

It is not entirely resolved whether the Early to Middle Miocene genus Capitonides from Europe belongs to this family or the Asian barbets (now Megalaimidae). Indeed, given that the prehistoric birds somewhat resembled a primitive toucan (without these birds' present autapomorphies), 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 distal carpometacarpus similar to that of barbets and found at the Middle Miocene locality of Grive-Saint-Alban (France) was considered to differ from Capitonides in the initial description, being closer to extant (presumably Old World) barbets. This fossil is sometimes lumped into Trachyphonus too; in this case it may have more merit.

Supposed fossil remains of Late Miocene Pogoniulus were found at Kohfidisch (Austria) 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.

Sources cited

• Ballmann, Peter (1969): Les Oiseaux miocènes de la Grive-Saint-Alban (Isère) [The Miocene birds of Grive-Saint-Alban (Isère)]. Geobios 2: 157–204. [French with English abstract] doi:10.1016/S0016-6995(69)80005-7 (HTML abstract)
• Mlíkovský, Jirí (2002): Cenozoic Birds of the World, Part 1: Europe. Ninox Press, Prague. ISBN 80-901105-3-8 {{isbn}}: ignored ISBN errors (link) PDF fulltext