Description of two new Cisticola species endemic to the marshes of the Kilombero floodplain of southwestern Tanzania

The presence of two undescribed cisticola warblers in the marshes of the Kilomberofloodplain in central Tanzania has been known since the 1980s and these putative newspecies have been illustrated infield guides on African birds, although with no formalname. Here we name both species, based on two museum specimens collected in 1961and recently detected in a museum collection. We use these specimens to provide formaldescriptions of each form and, using DNA sequence data extracted from these speci-mens, we place them in a broad phylogenetic framework for the genusCisticola. Thephylogenetic placement indicates that one of the new species is nested within a group ofplain-backed duetting cisticolas and the other within the streak-backed marsh cisticolas.We use our own and public recordings to characterize the vocal repertoire of each ofthese new species and compare song characteristics with other members of their respec-tive clades. Dating of nodes in the molecular phylogeny suggests that both cisticolasendemic to the Kilombero became isolated and diverged from their sister-speciesbetween 2.5 and 3.5 million years ago, long after the formation of the Eastern ArcMountains and the Malawi Rift. We propose that both species should be classified asglobally endangered, owing to immense anthropogenic pressures on thefloodplain, asdocumented in several publications and by a recent Ramsar Advisory Mission.