Two New Bird Species Discovered in West Africa

An international team of ornithologists has identified two new, cryptic species of birds — a long-tailed cuckoo and a barbet — living in West Africa.

The yellow-spotted barbet (Buccanodon duchaillui). Image credit: Romain Risso / CC BY-SA 3.0.

Belgian ornithologist Peter Boesman and Professor Nigel Collar of the UK’s Natural History Museum and BirdLife International focused on two bird species that have been well recognized for many years: the dusky long-tailed cuckoo (Cercococcyx mechowi) and the yellow-spotted barbet (Buccanodon duchaillui).

“Western and eastern populations of the dusky long-tailed cuckoo and the yellow-spotted barbet are known to have very different voices,” they said.

“The cuckoo has two song types, a melodious three-note whistle and a plaintive whinnying in West Africa west of the Bakossi Mountains in Cameroon, and a much less melodious, higher-pitched three-note whistle and a much faster whinnying in Central Africa east of the Bakossi Mountains.”

“The barbet has an accelerating song of some 6-11 hoots west of the Dahomey Gap and a rapid rolling purr to the east.”

“It might briefly be imagined that seasonal, age or sex differences could account for a single species possessing more than one vocalization, but the complete geographical separation of vocal types places such a notion beyond plausibility.”

“We therefore investigated the cases of these two species with three questions in mind: (i) are there subtle differences in plumage or morphometrics by which the different-voiced populations can be discriminated? (ii) are these populations sufficiently different in voice to be considered separate species? (iii) can we confirm that the lines separating the different-voiced populations fall for the cuckoo at the Sanaga River in Cameroon and for the barbet at the Dahomey Gap between Ghana and Nigeria.”

A long-tailed cuckoo (Cercococcyx sp.). Image credit: Engel et al, doi: 10.1111/ibi.12145.

In the study, Boesman and Professor Collar examined western and eastern specimens of the dusky long-tailed cuckoo and the yellow-spotted barbet from museums around the world.

They also assembled and analyzed sound-recordings of the songs of the birds.

The results showed that the western and eastern populations are, in fact, completely separate species.

The researchers named the new birds the whistling long-tailed cuckoo (Cercococcyx lemaireae) and the western yellow-spotted barbet (Buccanodon dowsetti).

“The whistling long-tailed cuckoo extends from Sierra Leone east to western Cameroon,” they said.

“The western yellow-spotted barbet ranges from Sierra Leone east to southern Ghana, being wholly absent from Togo and Benin.”

The new species are described in a paper published in the June 2019 issue of the Bulletin of the British Ornithologists’ Club.

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Peter Boesman N.J. Collar. 2019. Two undescribed species of bird from West Africa. Bulletin of the British Ornithologists’ Club 139 (2): 147-159; doi: 10.25226/bboc.v139i2.2019.a7