Lybiidae Explained

Lybiidae is a family of birds also known as the African barbets. There are 42 species ranging from the type genus Lybius of forest interior to the tinkerbirds (Pogoniulus) 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, 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.

Taxonomy

The phylogenetic relationship between the African barbets and the eight other families in the order Piciformes is shown in the cladogram below.[1] [2] The number of species in each family is taken from the list maintained by Frank Gill, Pamela C. Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC).[3]

Description and ecology

Most African barbets are about 20cm–25cmcm (10inches–10inchescm) 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 7g and 9cm (04inches).

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

Image Genus Living Species
Gymnobucco
Stactolaema
Pogoniulus – tinkerbirds
Buccanodon – yellow-spotted barbets
Tricholaema
Lybius
Pogonornis

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,[4] 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.[5] 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)[4] 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.

References

Notes and References

  1. Kuhl . H. . Frankl-Vilches . C. . Bakker . A. . Mayr . G. . Nikolaus . G. . Boerno . S.T. . Klages . S. . Timmermann . B. . Gahr . M. . 2021 . An unbiased molecular approach using 3′-UTRs resolves the avian family-level tree of life . Molecular Biology and Evolution . 38 . 1 . 108-127 . 10.1093/molbev/msaa191 . free . 21.11116/0000-0007-B72A-C . free .
  2. Stiller . J. . etal . 2024 . Complexity of avian evolution revealed by family-level genomes . Nature . 629 . 851-860 . 10.1038/s41586-024-07323-1 . free . 11111414 .
  3. Web site: Gill . Frank . Frank Gill (ornithologist) . Donsker . David . Rasmussen . Pamela . Pamela C. Rasmussen . December 2023 . IOC World Bird List Version 14.1 . International Ornithologists' Union . 17 June 2024 .
  4. Mlíkovský (2002)
  5. Ballmann (1969)