Sunday, 1 September 2013

A new site for Grauer’s Swamp Warbler in Uganda confirmed

Grauer’s Rush Warbler (GRW) Bradypterus graueri is restricted to highland swamps in the mountains around Lake Kivu and Edward in the Eastern part of the Democratic Republic of Congo, South -Western Uganda, Rwanda and Northern Burundi. The Grauer’s Swamp Warbler is described as globally endangered by the global Red data list of IUCN.
Grauer's Rush Warbler
The specie is endemic to the Albertine rift and can be identified by its medium sized dark brown plumage with white spots on breast. Its outstanding trill for a song cannot be missed in its swamp habitat. Little is known about their population, size, feeding behaviour, and there is scanty information on breeding biology.

Until recently, the species was only known from Muchuya swamp in Echuya Forest Reserve, Mubwindi Swamp in Bwindi Impenetrable National Park and Kagezi swamp in Mgahinga National Park.

NatureUganda monitors the population in Echuya forest and a survey of the swamp early this year, recorded 65 individual birds in 10 days.

Early this year, Zoreka Keresi one of the field based staff of NatureUganda reported of hearing calls of Warbler from two degraded swamps of Mukinombe and Kinyarushengye along the Kashasha stream that flows from Echuya Forest down to Lake Bunyonyi. Zoreka is conversant with the call and identification of the warbler since he has been working in Echuya Forest for over 15 years.

Swamp degradation
A team from NatureUganda headed by the ED, Mr Achilles Byaruhanga, visited the two remnant swamps on 11th August 2013 to confirm the earlier observation. Twenty eight (28) individual birds were recorded from Mukinombe swamp. This swamp that measures about 5-6 acres is highly degraded with less than two acres of vegetation above 3ft. The birds were easy to see or flush from the vegetation. At several occasions the warbler flew from the swamp into the sorghum gardens that provided better cover. This particular patch is heavily encroached on despite the fact that it is believed to be community owned and protected.

At Kinyarushenge area, the swamp measuring about 3 acres looked more degraded like it had been cultivated before. Although the swamp is dominated by Cyperus species, there was hardly any water. The swamp is partly owned by an individual and a Primary school. Here the birds were even more exposed preferring to hide in marginal bushes between gardens and the wetland. At this swamp 16 individuals were counted.

In both (Mukinombe and Kinyarushenge) swamps, the birds were calling an indication that there was breeding activity and probably explaining the high number of individuals recorded as well as the fact that birds are restricted to a small area. This is probably the highest number of individuals ever to be recorded from one site making these two patches of the swamp globally important and critical for the survival of the species. These new sites could be host to a lot more individuals considering the individuals that were not seen and thus not recorded and that Kashasha river belt continues to join Lake Bunyonyi with wetland pockets of similar habitat to those that were visited.

Until August 2013, this specie was known to occur in pristine swamps and was interesting to observe that Grauer’s Swamp Warbler can survive in such highly degraded and marginal swamps. This may present an opportunity to conserve this population outside protected areas. There has been a lot of swamp attenuation in many parts of the country as a result of drainage for agriculture and the cutting and burning of marsh vegetation. NatureUganda is planning for extensive surveys of the species along the Kashasha stream and other remnant swamp around Echuya Forest and Lake Bunyonyi to locate any other pockets of swamps that may contain other populations. Although working with communities may protect the swamps in the short run, there will be need for a landscape plan to protect the whole catchment of the Echuya Forest and accord these little swamps a high level of protection. These swamps qualify as Important Bird Areas (IBAs) and developing community conservancies through partnerships with community land owners and local governments for the protection of these critical sites for the Grauer’s Swamp warbler is paramount.

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