Investigation of the status of the enigmatic White-chested Tinkerbird Pogoniulus makawai using molecular analysis of the type specimen

Following the discovery of a uniquely plumaged Pogoniulus tinkerbird in Cryptosepalum forest in northwest Zambia in 1964 and its subsequent description in 1965 as a distinct species, White-chested Tinkerbird Pogoniulus makawai, there has long raged a debate regarding its taxonomic status. The failure to find further individuals in spite of numerous attempts has led several taxonomists to question its status as a distinct species. Using DNA from the P.makawai type specimen we performed a molecular phylogenetic analysis including samples from other tinkerbird species and, in particular, several subspecies of Yellow-rumped Tinkerbird Pogoniulus bilineatus, of which several observers considered the P.makawai specimen an aberrant individual. Phylogenetic analyses of both mitochondrial and nuclear DNA recovered P.makawai as being nested within a clade of Yellow-rumped Tinkerbirds. Our results suggest that White-chested Tinkerbird is not a distinct species but either a distinct subspecies or an aberrant form of Yellow-rumped Tinkerbird; in either case a genetic basis for plumage differences cannot be ruled out. At present our limited nuclear DNA data do not suggest hybridization with another tinkerbird species. Finally, we suggest that further surveys are needed to determine the extent to which loci that may underpin the makawai phenotype' may persist in the region, as well as to ascertain the extent to which the P.makawai form itself, or the entire regional population of Yellow-rumped Tinkerbirds, warrants subspecific status.