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Dwarf Ibis

Bostrychia bocagei


The Dwarf Ibis (also known as Dwarf Olive Ibis or São Tomé Ibis) is a small forest dwelling bird found on the island of São Tomé.

It had only been known from historical records and anecdotal evidence until a confirmed sighting in 1989. There have been a number of sightings since, during an ongoing study which hopes to identify the most important areas for the species on the island and develop a population estimate.

Their most suitable habitat is being surrounded and encroached by a very large-scale palm oil plantation, which has already destroyed the secondary forest belt where ibises were previously found, and which acted as a defensive barrier for the core of the population within the primary forest. Hunting, although typically opportunistic, is the biggest threat facing the Dwarf Olive Ibis. This is exacerbated by the fact that the species is tame and easy to spot.

A species action plan has been developed which will hopefully be the impetus for conservation of the species. Research into the species ecology is ongoing and is vital for future conservation measures.

  • Order: Pelecaniformes
  • Family: Threskiornithidae
  • Population: 70-400
  • Trend: decreasing
  • Size: 60-65 cm

EDGE Score

EDGE Score: 5.53 (?)
ED Score: 14.71 (?)
GE / IUCN Red List (?)
Not Evaluated Data Deficient Least Concern Near Threatened Vulnerable Endangered Critically Endangered Extinct in the Wild Extinct


South central region of the island of São Tomé off the coast of West Africa.

Habitat and Ecology

Found in old growth forest up to 500m above sea level. It appears that the species is not limited to primary forest as there have been sightings near palm plantations and secondary forest. There is also evidence that the species prefers areas that have been disturbed by wild pigs or along watercourses. Their ecology is not fully understood due to the limited number of sightings. They forage on the forest floor, feeding on invertebrates, snails and slugs.

Find out more

Conservation Actions

For each key category of conservation action, we calculated a conservation attention score based on expert information. In this graph, a higher score means the action is being carried out more intensively over more of the species range. The colour shows how important each action is considered to be for the conservation of this species.

Engaging stakeholders
Addressing threats
Status of knowledge
Management plan
Capacity building
Behaviour change
Awareness raising
  Score: 100 means the activity occurs at high level across more than 75% of the species range
Very Low

Overall Conservation Attention

We combined all of the expert information on conservation actions to calculate an overall conservation attention score for this species. Please help us to reach our goal of establishing dedicated conservation attention at “High” levels for all EDGE species.

Very Low Low Medium High

More information

Recent studies have grouped all possible conservation activities for any species into nine key categories (Washington et. al 2015). For each action, we asked experts for each species to assess the extent to which that action is being carried out and how much of the species’ range that action occurs in. For each action we used these two pieces of information to calculate the conservation attention score per action. A score of 100 means that the action is being carried out to a high level across at least 75% of the species range. We then combined the scores for all actions into an overall conservation attention score for the species. The experts also judged how important each category was to the conservation of that particular species.

This wordcloud illustrates the threats facing this species. The size of each word indicates the extent of a species range that is affected by that threat (larger size means a greater area is affected). The colour of the word indicates how much that threat impacts the species (darker shades of red mean the threat is more severe).

Crops Roads/Rail Hunting Logging Dams Invasive species

Threat wordcloud key:

Small area affected
Large area affected
Least severe
Most severe
Severity unknown
Source: The IUCN List of Threatened Species. Version 2017.1.
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