• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Justification of Red List category
Despite being described as common, this species potentially has a small population size. It is associated mostly with agroforests and non-forested areas, which might make it vulnerable to agricultural intensification. There is no strong evidence to support declines though, and so the species is listed here as Near Threatened. Further evidence regarding population trends and size could though mean that the species warrants re-categorising in the future.

Population justification
The species has been described as common across the island (Fry and Keith 2004; Craig 2018). Yet, a recent survey found the species at only 268 out of 3,056 point counts (Soares 2017). Using population densities estimates for congeners (although these are for continental species), the population size may fall in the range 1,000-2,499 mature individuals. However, this species is gregarious, so multiple individuals can be found at a single point count (Jones and Tye 2006), and island species often occur at higher densities (R. F. de Lima in litt. 2018). Therefore, the population size is very tentatively placed here in the range 2,500-9,999 mature individuals.

Trend justification
The species is tolerant of degraded habitats, so habitat degradation is unlikely to impact this species. However, its tolerance of degraded habitats may bring it into contact with introduced predators such as House Rats (Rattus rattus), but it is highly uncertain whether such predators are having an impact on the species at all. The species is very precautionarily suspected to be declining, but further information could show the species to be stable or even increasing.

Ploceus grandis is endemic to the island of São Tomé, São Tomé and Príncipe (Craig 2018). It is patchily common, most frequently found in agroforests and in non-forested areas. It is estimated to exist in an area of 777 km² of suitable habitat (Soares et al. 2020).

This species occurs in a range of habitat types up to 1,500 m, but it prefers agroforest and non-forested areas (Soares et al. 2020). It feeds on fruits and invertebrates, and can be locally abundant. It breeds in loose colonies but little is known about its breeding ecology (Jones and Tye 2006).

This species prefers habitats with an intermediate level of disturbance (Soares et al. 2020). While the species could therefore not be as severely impacted by forest loss as other species endemic to the island, this could mean that population core of this species relies on anthropogenic environments, which may be prone to the impact of human activities such as agricultural activities (Oyono et al. 2014). Several introduced mammals such as Black Rat Rattus rattus, African Civet Civettictis civetta, feral cats Felis catus, and Mona Monkey Cercopithecus mona are potential predators of adults and nests (Dutton 1994).

Conservation Actions Underway
This species is considered protected by law 11/1999, and a small part of its range falls within the São Tomé Obo Natural Park. Hunting this species is forbidden. There are several ongoing projects supporting forest conservation, for example the ECOFAC6 intiative 2018-2022, however this might overlook species that are less reliant on forests.

Conservation Actions Proposed
Research the ecological requirements, particularly breeding, feeding and detailed habitat requirements. Establish threats, population size and trends. Ensure the implementation of existing environmental laws. Maintain suitable land-use regimes to provide habitat with intermediate levels of disturbance.

Text account compilers
Clark, J.

Contributors
Butchart, S., Deffontaines, J., Ekstrom, J., Westrip, J.R.S. & de Lima, R.F.

---

Recommended citation
BirdLife International (2024) Species factsheet: Giant Weaver Ploceus grandis. Downloaded from https://datazone.birdlife.org/species/factsheet/giant-weaver-ploceus-grandis on 23/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 23/12/2024.