The São Tomé ibis, also known as the dwarf olive ibis or the dwarf ibis, is a critically endangered bird that is endemic to São Tomé off the western coast of Central Africa in the Gulf of Guinea. Discovered in the 1800s by Francisco Newton, it was once thought to be a subspecies of the larger olive ibis, but is now classified as a distinct species.
Region
Gulf of Guinea (São Tomé Island)
Typical Environment
Occurs in primary and mature secondary rainforest, especially in rugged, humid interior mountains with dense understory. Prefers steep ravines, stream gullies, and areas with thick leaf litter where invertebrates are abundant. It avoids heavily disturbed lowland habitats and plantations, persisting mostly in relatively intact forest tracts. Roosting typically occurs in tall forest trees, often near watercourses.
Altitude Range
600–1400 m
Climate Zone
Tropical
Ease of Keeping
Beginner friendly: 1/5
Also called the dwarf olive ibis, this elusive forest ibis is confined to São Tomé Island in the Gulf of Guinea. It forages quietly on the shaded forest floor and is most active at dawn and dusk. Ongoing habitat loss and disturbance are its main threats, and it is one of Africa’s rarest birds. Conservation actions focus on safeguarding primary montane rainforest within Obô Natural Park.
The island of São Tomé off the coast of Africa
Overall population increases in São Tomé and Príncipe. The increase in population has increased the demand for resources which has consequently limited the available habitat for the dwarf ibis. Population of São Tomé (in thousands) is shown on the y-axis and time is on the x-axis.
Oil palm plantation
The entrance to Obô National Park in São Tomé.
Temperament
shy and elusive
Flight Pattern
short rapid wingbeats through forest gaps; low, direct flights between roosts and foraging sites
Social Behavior
Usually encountered singly, in pairs, or small family groups. Nests are placed in tall forest trees, often over ravines or near streams. Territorial during breeding, with discreet movements and low-profile behavior in dense vegetation.
Migratory Pattern
Resident
Song Description
Vocalizations are low, gruff grunts and croaks, often given at dawn or dusk. Calls carry poorly through dense forest, adding to the species’ secretive reputation.
