Grauer’s scrub-warbler

Description

Despite being locally common,this species has a very small and severely fragmented area of occupancy within its small overall range.Many sites are being converted to cultivation or pasture.Thus the species's area of occupancy is declining and,by inference,so is the number of mature individuals.It is therefore classified as Endangered.Bradypterus graueri is found in Rwanda,Burundi,eastern Democratic Republic of Congo (DRC) and south-western Uganda.In Rwanda,it occurs in Rugezi Swamp (Vande Weghe 1983) (probably the largest subpopulation),in the marshes between the Virunga volcanos (Vande Weghe 1983),and in Nyungwe (Rugege) Forest (Vande Weghe 1983,Dowsett-Lemaire 1990).In Burundi,in 1984,the national population was estimated at only c.10 pairs,however at least 30 singing birds were estimated from Mwokora,Kibira National Park,in 2011 (Anon.2011).In the DRC,it is known from at least six locations west of Lakes Edward and Kivu (Chapin 1953,Friedmann and Williams 1968,T.Butynski in litt.1999).In Uganda,it occurs in Echuya Forest Reserve (the 700 ha Muchuya swamp formerly thought to hold large numbers,but c.50 pairs estimated here by Ellison [2009]) and Bwindi-Impenetrable National Park (c.400 birds) (Davenport et al.1996,T.Butynski in litt.1999).The density at Kamiranzovu Swamp,Nyungwe,is about 13 birds per ha based on surveys of singing birds (A.Plumptre in litt.2007).The swamp is c.25 km2,resulting in an estimate of 33,000 birds at this site alone (A.Plumptre in litt.2007).The species's total area of occupancy is probably c.200-250 km2 (Arinaitwe 1996,Mwambu 1999)