Black-billed Barbet (Lybius guifsobalito)
The Lybius genus belongs to the order Piciformes, which contains 8 families, including the woodpecker family. A couple of decades ago, all barbets were thought to be of one family, but studies of mitochondrial DNA and DNA hybridization in the early 1990s have led to barbets being split into three families: Asian barbets (Megalaimidae), African barbets (Lybiidae), and American barbets (Capitonidae). The Lybiidae family has a total of 42 species that occur throughout the continent of Africa from the tip of the Cape Peninsula to the fringes of the Sahara desert. Out of the 42 species in this family, the Lybius genus contains 12 barbet species. These 12 species are the most frequently encountered group of African barbets.
The Lybius species are usually about 20–25 cm (7.9–9.8 in) long, plump-looking, with large heads, and their heavy bill is fringed with bristles. Almost all species in this genus are characterized by their red feathers on the head or around the eyes, but there is a great variety of morphology in this genus. There are barbets like the white-headed barbet that have no red on the head at all, and species like the double-toothed barbet with all red feathers on the ventral side of the body and head, but with only black on the dorsal side.
Most of the Lybius species use duetting as a way to mark one's territory and to find a mate. Mates must have coordinating duets in order to be a proper match for each other, which means lone singers are very uncommon in the duetting barbet species. Duet songs are species-specific, and only paired duetting barbets can hold a territory, which is why lone singers are rarely seen. There are four known duetting species in this genus: Lybius vieilloti, Lybius leucocephalus, Lybius rubrifacies, and Lybius torquatus. The duetting of Lybius chaplini and Lybius undatus is unknown. The behavioral significance of duetting probably involves sex recognition and the maintenance of a pair bond.
Generally, the barbets in the duet will bow ceremoniously to each other while singing. In addition to bowing, certain African barbet species, like Lybius vieilloti and Lybius torquatus, will incorporate a snarl into their duet. The snarl might actually be how the duets are initiated in this species. When duetting, each bird will pick up the song from where the other bird left off. The time interval between when one bird ends the duet and when the other bird begins the song again is called the "auditory response time". Basically, the auditory response time is the minimum time required for the barbet to hear the notes and respond to them.
It contains the following species:
Double-toothed Barbet (Shaw, 1798) (Lybius bidentatus) Chaplin's Barbet (Clarke, 1920) (Lybius chaplini) Bearded Barbet (Gmelin, 1788) (Lybius dubius) Black-billed Barbet (Hermann, 1783) (Lybius guifsobalito) White-headed Barbet (De Filippi, 1853) (Lybius leucocephalus) Brown-breasted Barbet (Peters, 1854) (Lybius melanopterus) Black-backed Barbet (Cuvier, 1816) (Lybius minor) Black-breasted Barbet (De Filippi, 1853) (Lybius rolleti) Red-faced Barbet (Reichenow, 1892) (Lybius rubrifacies) Black-collared Barbet (Dumont, 1816) (Lybius torquatus) Banded Barbet (Rüppell, 1837) (Lybius undatus) Vieillot's Barbet (Leach, 1815) (Lybius vieilloti)