email a friend
printable version
Location Guinea-Bissau, Biombo,Cacheu
Central coordinates 15o 54.00' West  11o 55.00' North
IBA criteria A1, A3, A4i, A4iii
Area 119,743 ha
Altitude 0 - 10m
Year of IBA assessment 2001

Site description The site comprises much of the estuary, fringing mangrove and woodland of the Rio Mansôa, together with an area of the northern shore of the Canal do Gêba, the estuary of the larger Rio Gêba, immediately to the east. The site includes two large, predominantly mangrove-covered islands—Ilha de Jeta and Ilha de Pexice—as well as several smaller ones in the mouth of the Rio Mansôa. Eastwards the site extends along the shoreline of the Canal do Gêba as far as the Ilhéu dos Pássaros, an islet near the northern shore of the estuary of the Rio Gêba, a little way downstream of the city of Bissau. The banks of the mouth of the Rio Gêba are bordered with mangroves and soft mud, while there are sandbars and mudbanks in the channel. The site includes 175,000 ha of mudflats, 3,000 ha of mangrove and 13,000 ha of marsh.

Key Biodiversity See Box and Table 2 for key species. The Ilhéu dos Pássaros is an important roost-site where over 15,000 birds have been recorded. Counts only exist for the eastern parts of the site, the Rio Gêba area, which alone held over 37,000 wintering waders. A count of 1,500 Phoenicopterus minor were recorded in March 1990.

Non-bird biodiversity: The mammal Trichechus senegalensis (VU) occurs.

Populations of IBA trigger species

Species Season Period Population estimate Quality of estimate IBA Criteria IUCN Category
Lesser Flamingo Phoeniconaias minor winter  1990  1,500 individuals  A1  Near Threatened 
Egretta gularis winter  1988  2,244 individuals  A4i  Not Recognised 
Black Heron Egretta ardesiaca winter  1988  1,354 individuals  A4i  Least Concern 
Charadrius alexandrinus winter  1,500 individuals  A4i  Not Recognised 
Grey Plover Pluvialis squatarola winter  3,200 individuals  A4i  Least Concern 
Common Ringed Plover Charadrius hiaticula winter  7,800 individuals  A4i  Least Concern 
Bar-tailed Godwit Limosa lapponica winter  23,800 individuals  A4i  Near Threatened 
Ruddy Turnstone Arenaria interpres winter  700 individuals  A4i  Least Concern 
Curlew Sandpiper Calidris ferruginea winter  10,000 individuals  A4i  Near Threatened 
Collared Pratincole Glareola pratincola winter  1983  2,500 individuals  A4i  Least Concern 
Senegal Parrot Poicephalus senegalus resident  1997  present  A3  Least Concern 
Blue-bellied Roller Coracias cyanogaster resident  1997  present  A3  Least Concern 
Red-throated Bee-eater Merops bulocki resident  1997  present  A3  Least Concern 
Yellow-billed Shrike Corvinella corvina resident  1997  present  A3  Least Concern 
Piapiac Ptilostomus afer resident  1997  present  A3  Least Concern 
Purple Glossy-starling Lamprotornis purpureus resident  1997  present  A3  Least Concern 
Bronze-tailed Glossy-starling Lamprotornis chalcurus resident  1997  present  A3  Least Concern 
White-fronted Black-chat Myrmecocichla albifrons resident  1997  present  A3  Least Concern 
White-cheeked Oliveback Nesocharis capistrata resident  1997  present  A3  Least Concern 
Lavender Waxbill Estrilda caerulescens resident  1997  present  A3  Least Concern 
A4iii Species group - waterbirds winter  50,000-99,999 individuals  unknown  A4iii   

Protected areas

Protected area Designation Area (ha) Relationship with IBA Overlap with IBA (ha)  
Rio Geba/Rio Mansoa Hunting Reserve 0 protected area contained by site 0  


IUCN habitat Habitat detail Extent (% of site)
Artificial - terrestrial   16%
Shrubland   1%
Savanna   5%
Forest   75%

Land use

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

References Altenburg and van Spanje (1989), Ledant (1985), Zwarts (1988).

Contribute  Please click here to help BirdLife conserve the world's birds - your data for this IBA and others are vital for helping protect the environment.

Recommended citation  BirdLife International (2016) Important Bird and Biodiversity Area factsheet: Rio Mansôa and Gêba estuary. Downloaded from on 23/10/2016

To provide new information to update this factsheet or to correct any errors, please email BirdLife