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

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	C2a(i)	C2a(i)

Red List history

Year	Category	Criteria
2021	Endangered	C2a(i)
2016	Endangered	C2a(i)
2012	Endangered	C2a(i)
2008	Endangered	C2a(i)
2004	Endangered
2000	Endangered
1996	Vulnerable
1994	Vulnerable
1988	Threatened

Migratory status	not a migrant	Forest dependency	high
Land-mass type	continent	Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	68,800 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	1000-3500 mature individuals	poor	estimated	2021
Population trend	decreasing	poor	inferred	2016-2026
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-15%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-15%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-15%	-	-	-
Generation length	3.46 years	-	-	-
Number of subpopulations	5	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: Based on this species’s apparent rarity, and the scarcity of records, taking the lower quartiles of density estimates of a forest-dwelling congener, the Southern Masked-weaver Ploceus velatus, of 0.59-2 individuals/sqkm (BirdLife Population Density Spreadsheet; Vernon 1985; Dean 1995), and assuming it inhabits 5% of the forest within its range (51,700 sqkm [Global Forest Watch 2021]), the population may fall in the band 1,525-5,170 individuals. This is roughly equivalent to 1,016-3,447 mature individuals rounded here to 1,000-3,500 mature individuals. Furthermore, if it is known from 5 different sites (H. Rainey in litt. 2021), this species may have multiple subpopulations, so it is plausible that there may be <1,000 mature individuals in the largest subpopulation.

Trend justification: This species has a high forest dependency and is therefore inferred to be declining in line with continued habitat loss and degradation (Global Forest Watch 2021; Tchoumbou et al. 2020). During the years 2000-2019, this species's range experienced a 5.2% loss in forest cover (Global Forest Watch 2020). This equates to a loss of 2.9% over 3 generations. Tchoumbou et al. (2020) suggest that overall, the rate of deforestation in Cameroon is higher, at a 1% loss per annum. This would equate to a loss of 10% over 3 generations for this species. During the years 2016-2019, this species's range experienced forest cover loss of 2.2% (Global Forest Watch 2020). Projected forward over 10 years this equates to a loss of 5.7%. If the rate of deforestation suggested by Tchoumbou et al. (2020) continues (at 1% per annum), that would equate to 10% over 10 years. Assuming that the population declines at a similar rate to forest loss, the rate of decline is suspected to fall in the band of 1-15%.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Cameroon	extant	native	yes

Country/Territory	IBA Name
Cameroon	Mount Cameroon and Mokoko-Onge
Cameroon	Mount Kupe

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Altitude	0 - 900 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Agro-industry farming	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Rapid Declines		Low Impact: 5
		Stresses Ecosystem conversion
Agriculture & aquaculture	Annual & perennial non-timber crops - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Species disturbance, Ecosystem degradation, Ecosystem conversion
Invasive and other problematic species, genes & diseases	Problematic native species/diseases	Timing		Scope		Severity		Impact
		Unknown		Majority (50-90%)		Unknown		Unknown
		Stresses Competition
Natural system modifications	Other ecosystem modifications	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Bates's Weaver Ploceus batesi. Downloaded from https://datazone.birdlife.org/species/factsheet/batess-weaver-ploceus-batesi on 22/11/2024.
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 22/11/2024.