Conclusions and Recommendations

 


Guinea-Congo Biome in Tanzania

 

Minziro Forest Reserve is one of three protected areas in Tanzania where Guinea-Congo species are known to occur. The other two areas are Mahale Mountains National Park and Rubondo Island National Park. Due to the data collected by four ornithological studies over the past 14 years, Minziro is the best studied (in ornithological terms) of these areas. From what little biological knowledge we have, it is clear that Minziro Forest Reserve is of great importance to the overall biodiversity of Tanzania. Of the 58 species of birds recorded in Tanzania which are restricted to the Guinea – Congo Biome, 56 are known only from Minziro. In national terms, from a total of 1107 species of birds so far recorded in Tanzania (January 2001 figure), 5% (n=56) of the country’s total avifaunal diversity may occur at only this locality. If Minziro provides the habitat for so many predominately west African bird species, it is likely that this will also be mirrored by other fauna.

 

Importance of the Kagera River eco-system to Minziro Forest Reserve

 


The Kagera River forms the border between Rwanda and Tanzania for a distance of 210 km (Hughes & Hughes, 1992), before flowing east along the Ugandan border south and east of Minziro and into lake Victoria. The river rises and floods following rains over the catchment areas in Rwanda and Burundi. In total about 35,000 ha of papyrus dominated wetland are situated in Tanzania (Hughes & Hughes, 1992). Minziro, a swamp forest by definition, is greatly affected by the Kagera River and seasonal flooding often results in several feet of water covering the forest floor. This is especially obvious where the river forms the eastern boundary of the reserve near Nyakabanga. Here seasonal flooding totally alters the conditions within the forest and effects much of the ground dwelling flora and fauna. The resident flora and fauna that occur in Minziro are thus comprised of unique assemblages of species which are tolerant of such conditions.

 

The papyrus beds that fringe the 37.5 km (measured figure from 1:50,000 map) of river within, and bordering the reserve, provide an important habitat for bird species. The Kagera River eco-system is an important area for both humans and wildlife. Although Hippopotamus amphibius is now rare (Hughes & Hughes, 1992), other fauna such as crocodiles, otters and monitor lizards occur. With the degazettement of 70.7 % of protected area in the Kagera Region, Rwanda, further losses of biodiversity are expected in Acacia Kirkii gallery forest along the Kagera River (Williams and Ntayombya, 1999). This degazettement includes 66% of the Kagera National Park (Rodgers pers comm) resulting in the Kagera river eco-system having very little protection. The large number of people and habitat damage observed along Lake Rushwa, South of Rumanyika Game Reserve would indicate a wider threat to this wetland eco-system. Hughes & Hughes (1992) state that the river and associated swamps and lakes are subject to intensive hunting and fishing. It is unknown how these developments may effect the long term maintainance of Minziro Forest Reserve.

 

Importance of Minziro Forest Reserve for Bird Conservation

 


The initial ornithological work which began with a brief visit in 1984 and was then followed by a ringing expedition to Minziro in 1987, already represents one of the longest running ringing and re-capture sights within Tanzania. Previous studies on birds within this biome have been by Brosset, A. and Erard, C. who carried out mist-netting over a period of 8 years in Gabon. The seven re-captured birds, first ringed in Minziro, July 1987, have provided valuable data on species longevity and ecology. The proof that some of these afro-tropical forest species are sedentary is extremely useful in conservation planning. It is generally thought that some of these sedentary forest species find a habitat and remain there for life, becoming totally familiar with their home range thus increasing their chance of survival and breeding success (Oatley, T pers comm). It is almost certain that when the habitat within species home range is degraded, the birds do not and often cannot move out of the area to more suitable habitat. This results in a decline in breeding success and thus the health of the overall population in question. 

It must be noted however that in a global or afro-tropical sense, there are only two species for which the habitats within this reserve are internationally important. Blue Swallow H. atrocaerulea, current status; vulnerable (10% chance of extinction in 100 years) is likely to be upgraded to endangered (20% chance of extinction in 20 years) in Threatened birds of the World, due to be published by BirdLife International in the near future. Minziro Forest Reserve represents the only viable habitat in Tanzania which at present has any degree of protected status (see species of special interest).

 

Papyrus Gonolek L. mufumbiri, the second globally threatened species thought to occur in Minziro, is endemic to papyrus in swamps and river edge within Lake Victoria Basin (species of special interest). Although its actual numbers within the area are unknown, it is again important to note that Minziro is one of the few areas within this species range that may have some form of official protection[1].

 

Due to the presence of these two species, Minziro forest reserve meets the criteria for an important bird area (IBA. Fishpool, 1997). Map 2 shows the proposed boundary of the IBA within and outside of the reserve. This aims to concentrate attention onto the habitat for both of these globally threatened species.

 


[1] At present we are unsure whether the boundary of the forest reserve actually meets the river edge, or if it extends into the centre of the river.