EPOW - Ecology Picture of the Week

Barbet With the Black Throat

Black-throated Barbet (Tricholaema melanocephala stigmatothorax)
Family Capitonidae (sometimes Lybiidae)
Lake Baringo, Rift Valley, Kenya

Explanation:  This week and next, we are exploring the biota of one of the expansive lakes of the Rift Valley of east Africa, here in southern Kenya.  In the arid upland Acacia thorn scrub that rings the lake reside many interesting birds.  This week we have a good look at a Black-throated Barbet.

What makes a bird a barbet?  Barbets typically are chunky-bodied birds with large heads and thick bills.  At the base of the bill, and sometimes on the chin, grow modified feathers called bristles.  These are particularly evident in this week's photo.  

The function of bristles is unclear (Short and Horne 2001).  At times, the bristles can be flattened against the bill, perhaps to avoid damage or as a social signal although this is unstudied.  In an example of what may be evolutionary convergence, New World flycatchers (family Tytonidae) also sport facial bristles.  Perhaps bristles also serve as a sensory organ helping the birds catch insects or other prey, but again this is little studied.  

African barbets are usually placed in the taxonomic family Capitonidae with other Old World barbets of Asia, but some authors place them in their own family Lybiidae.

Black-throated Barbets occur only in east Africa.  They are typically found dashing quickly among low trees, making it most difficult to secure a nice photo portrait.   

Oh, and Black-throated Barbets are really brown (and white).  Go figure.

Information:
     Short, L., and J. Horne.  2001.  Toucans, barbets and honeyguides.  Oxford University Press.