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Location Tanzania, Mbeya
Central coordinates 34o 15.00' East  8o 30.00' South
IBA criteria A1, A3, A4i
Area 300,000 ha
Altitude 1,000 - 1,060m
Year of IBA assessment 2001





Site description This seasonally inundated flood-plain lies to the north of the Chimala Escarpment along the northern edge of the Kipengire mountains. To the west the Mbeya mountains extend north beyond Chunya and to the north and east lie gently rising hills cloaked in miombo woodland. Several major rivers flow from these highland areas to form the Ruaha river that meanders north-eastwards through the flood-plain before becoming the southern border of Ruaha National Park (TZ007). The natural vegetation of the Usangu varies from small areas of permanent swamp and waterside vegetation in numerous oxbow lakes, through open grassland (much of this is now permanent bare ground due to overgrazing) and thickets of Acacia seyal and Acacia kirkii thorn-bush. On slightly higher ground Commiphora and Combretum woodlands dominate (depending on soil characteristics) and these mix with miombo woodland towards the hills. In the more open, rocky areas baobabs are characteristic.The Great North Road runs along the base of the Chimala Escarpment and from this access point two commercial rice-schemes penetrate into the Usangu. These rice-schemes hold permanent water and are an important habitat for many birds, especially during the dry season (June–October). A new rice-scheme at Madibira will also become important to wetland birds, especially when permanent vegetation develops.

Key Biodiversity See Box and Table 3 for key species. Some 418 species have been recorded from the site. Most records of waterbirds are from a tiny area around the Mbarali and Kapunga rice-schemes and numbers of waterbirds in the whole site are likely to be larger than given. Most information is qualitative; ‘acres’ of Dendrocygna bicolor, for example. Balearica regulorum certainly occurred until recently in thousands and the population of Plectropterus gambensis may number tens of thousands. Among species likely to meet 1% thresholds are Egretta garzetta, Ardeola ralloides, Ardeola rufiventris, Mycteria ibis, Anastomus lamelligerus, Plegadis falcinellus, Dendrocygna bicolor, Plectropterus gambensis, Himantopus himantopus, Charadrius asiaticus and Vanellus albiceps. This is the only regular site known in East Africa for significant numbers of Glareola nordmanni. Grus carunculatus occurs at the Mbarali rice-scheme; 12 in January 1995. Acrocephalus griseldis is only known from a single record in 1995, but it may winter in reasonable numbers. Falco naumanni (passage) and Gallinago media (winter visitor) have been recorded in small numbers and there are several recent records of Circus macrourus.The Usangu is the only known locality in Tanzania that holds populations of four species of coucal; Centropus cupreicaudus, C. superciliosus, C. senegalensis and C. grillii all breed at Mbarali and the first three are likely to be resident there. Burned grassland is utilized by a small population of Ardeotis denhami that are probably cold-season altitudinal migrants from the nearby Kitulo plateau (TZ073). The Usangu basin represents the southernmost extension of the Somali–Masai arid corridor. This is reflected in the avifauna which includes two Tanzanian endemics, Cosmopsarus unicolor and Agapornis personatus.

Non-bird biodiversity: Large mammals listed for the site include Loxodonta africana (EN) and Panthera leo (VU). Lycaon pictus (EN) are likely to occur, but Diceros bicornis (CR) were extirpated during the late 1970s. There is a large selection of antelope including Hippotragus equinus (LR/cd) and H. niger (LR/cd).

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Trachyphonus darnaudii resident  2000  present  A3  Not Recognised 
Eastern Chanting-goshawk Melierax poliopterus resident  2000  present  A3  Least Concern 
Buff-crested Bustard Lophotis gindiana resident  2000  present  A3  Least Concern 
Wattled Crane Bugeranus carunculatus non-breeding  1995  12 individuals  A1  Vulnerable 
Collared Pratincole Glareola pratincola non-breeding  1995  1,500 individuals  A4i  Least Concern 
Black-winged Pratincole Glareola nordmanni winter  150 individuals  A1, A4i  Near Threatened 
Black-faced Sandgrouse Pterocles decoratus resident  2000  present  A3  Least Concern 
Yellow-collared Lovebird Agapornis personatus resident  2000  present  A3  Least Concern 
White-bellied Go-away-bird Criniferoides leucogaster resident  2000  present  A3  Least Concern 
Coppery-tailed Coucal Centropus cupreicaudus resident  2000  present  A3  Least Concern 
Racquet-tailed Roller Coracias spatulatus resident  2000  present  A3  Least Concern 
Abyssinian Scimitarbill Rhinopomastus minor resident  2000  present  A3  Least Concern 
Von der Decken's Hornbill Tockus deckeni resident  2000  present  A3  Least Concern 
Long-tailed Fiscal Lanius cabanisi resident  2000  present  A3  Least Concern 
Tabora Cisticola Cisticola angusticauda resident  2000  present  A3  Least Concern 
Grey Wren-warbler Camaroptera simplex resident  2000  present  A3  Least Concern 
Miombo Wren-warbler Camaroptera undosa resident  2000  present  A3  Least Concern 
Banded Warbler Sylvia boehmi resident  2000  present  A3  Least Concern 
Ashy Starling Cosmopsarus unicolor resident  2000  present  A3  Least Concern 
Kurrichane Thrush Turdus libonyanus resident  2000  present  A3  Least Concern 
White-headed Black-chat Myrmecocichla arnoti resident  2000  present  A3  Least Concern 
Miombo Rock-thrush Monticola angolensis resident  2000  present  A3  Least Concern 
African Grey Flycatcher Bradornis microrhynchus resident  2000  present  A3  Least Concern 
Kenya Violet-backed Sunbird Anthreptes orientalis resident  2000  present  A3  Least Concern 
Miombo Double-collared Sunbird Nectarinia manoensis resident  2000  present  A3  Least Concern 
Shelley's Sunbird Nectarinia shelleyi resident  2000  present  A3  Least Concern 
Swahili Sparrow Passer suahelicus resident  2000  present  A3  Least Concern 
White-headed Buffalo-weaver Dinemellia dinemelli resident  2000  present  A3  Least Concern 
Blue-capped Cordonbleu Uraeginthus cyanocephalus resident  2000  present  A3  Least Concern 
Purple Grenadier Uraeginthus ianthinogaster resident  2000  present  A3  Least Concern 
Red-rumped Waxbill Estrilda charmosyna resident  2000  present  A3  Least Concern 
Grey-headed Silverbill Lonchura griseicapilla resident  2000  present  A3  Least Concern 
Steel-blue Whydah Vidua hypocherina resident  2000  present  A3  Least Concern 
Broad-tailed Paradise-whydah Vidua obtusa resident  2000  present  A3  Least Concern 

IBA Monitoring

2009 very high unfavourable low
Habitat
Good - based on reliable and complete / representative data

Agricultural expansion and intensification annual & perennial non-timber crops - agro-industry farming happening now whole area/population (>90%) very rapid to severe deterioration very high
Agricultural expansion and intensification annual & perennial non-timber crops - small-holder farming happening now majority/most of area/population (50-90%) very rapid to severe deterioration very high
Agricultural expansion and intensification livestock farming and ranching (includes forest grazing) - small-holder grazing, ranching or farming happening now majority/most of area/population (50-90%) moderate to rapid deterioration high
Climate change and severe weather drought happening now some of area/population (10-49%) slow but significant deterioration medium
Human intrusions and disturbance work and other activities happening now majority/most of area/population (50-90%) moderate to rapid deterioration high
Invasive and other problematic species and genes invasive non-native/alien species/diseases - named species happening now whole area/population (>90%) moderate to rapid deterioration very high
Natural system modifications dams & water management/use - abstraction of surface water (agricultural use) happening now majority/most of area/population (50-90%) slow but significant deterioration high
Over-exploitation, persecution and control of species hunting & collecting terrestrial animals - intentional use (species being assessed is the target) happening now some of area/population (10-49%) slow but significant deterioration medium
Pollution agricultural & forestry effluents - herbicides and pesticides happening now some of area/population (10-49%) slow but significant deterioration medium
Pollution agricultural & forestry effluents - nutrient loads happening now some of area/population (10-49%) slow but significant deterioration medium
Residential and commercial development housing and urban areas happening now some of area/population (10-49%) slow but significant deterioration medium
Transportation and service corridors roads and railroads happening now small area/few individuals (<10%) slow but significant deterioration low

Grassland   0 0 moderate (70-90%) moderate (70-90%) unfavourable

Some of site covered (10-49%)  A management plan exists but it is out of date or not comprehensive  Substantive conservation measures are being implemented but these are not comprehensive and are limited by resources and capacity  low 

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Usangu Game Reserve 409,740 protected area contained by site 0  

Local conservation groups The local conservation group below is working to support conservation at this IBA.

Name Year formed
Usangu Site Support Group 1999

Habitats

IUCN habitat Habitat detail Extent (% of site)
Artificial - terrestrial   37%
Shrubland   10%
Grassland   49%
Forest   2%

Land use

Land-use Extent (% of site)
agriculture -
hunting -
nature conservation and research -

References Baker (1997), Elliott (1983), Ministry of Water (2000), Moirana and Nahonyo (1996), Procter (1968), Wright (1968).

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Recommended citation  BirdLife International (2014) Important Bird Areas factsheet: Usangu flats. Downloaded from http://www.birdlife.org on 28/12/2014

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