Papyrus swamp drainage and the conservation status of their avifauna

Abstract

Papyrus Cyperus papyrus swamps sustain the livelihoods of millions of people, but threats to this habitat have never been quantified formally. Birds are useful indicators of threats that cannot be measured directly. Using satellite imagery classification and habitat associated modelling, we quantify drainage and present International Union for Conservation of Nature (IUCN) Red List assessments for the eight taxa most closely associated with this habitat. We show that, between 1984–1987 and 1999–2001 the areal extent of papyrus declined by 6.7 % from 1,643 to 1,532 km². Papyrus-specialist avifauna has undergone much greater declines, due in part to fragmentation effects and in part to geographical overlap between areas of highest population densities and areas that have experienced greatest habitat loss. Our assessment does not alter the IUCN Red List status of any full species, but it improves current knowledge of the drivers of their extinction risk. Papyrus gonolek Laniarius mufumbiri should remain at least near threatened, but on the basis of population decline rather than a purported small and decreasing range size, and papyrus yellow warbler Chloropeta gracilirostris should remain vulnerable, but again due to declines rather than on the basis of previous under-estimates of population size. Other species should remain listed as least concern. However, taxonomically, likely specifically, distinct populations of papyrus yellow warbler in Zambia and Kenya are highly threatened and should be listed as endangered and critically endangered respectively. We propose several conservation priorities and discuss means of achieving these in a manner consistent with maintaining the livelihoods of people.