Data Zone
Justification of Red List category
This species is estimated to have a small population which is experiencing a continued decline owing to ongoing habitat degradation. It is therefore listed as Endangered.
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%.
Ploceus batesi is a rarely-recorded species from southern and western Cameroon, occurring in a narrow belt from Limbe, at the foot of Mt Cameroon (Taylor 1981) (although the observation at Limbe was not confirmed), east to Moloundou (Collar and Stuart 1985). In recent years, it has only been seen twice near the Dja Faunal Reserve (at Somalomo on the north-west boundary of the Reserve in 1995, and at Shwani, 12 km from Somalomo, in 1996) (R. Fotso in litt. 1999) and remains known from only a few localities, including Mt Kupe (two possible records in 1990, but none since, despite intensive searches). In 1998-2001, surveys in western and south-eastern Cameroon failed to relocate the species (F. Dowsett-Lemaire in litt. 2007).
It occurs in lowland rainforest, although all recent records come from secondary forest and forest edge, particularly degraded forest around villages (R. Fotso in litt. 1999, F. Dowsett-Lemaire in litt. 1999, 2000). It has been recorded on Mt Kupe up to 900 m. In 1979, a single bird was observed moving in a zig-zag manner up a creeper-covered tree-trunk (Taylor 1981), and it has been observed foraging under the canopy (R. Fotso in litt. 1999). It occurs singly and in pairs, and one record was in a mixed-species flock; it appears to use bark-gleaning to forage on insects.
Since it is a bark-gleaning species it may be in competition with Preuss's Weaver P. preussi (F. Dowsett-Lemaire in litt. 1999, 2000). In Cameroon, deforestation occurs due to agricultural expansion, and selective logging (Tchoumbou et al. 2020). A plan for a 70,000 ha palm oil plantation is underway and threatens to significantly fragment large areas of suitable habitat in southwestern Cameroon (Linder et al. 2012).
Conservation Actions Underway
The Dja Faunal Reserve is a protected area.
12-14 cm. Small forest weaver. Male has bright chestnut head with contrasting black throat which extends in band to nape. Small yellow collar separates head from rich olive-green upperparts. Bright golden-yellow underparts except for black on throat. Female very similar but has black, not chestnut, on head and lacks black throat and nape configuration of male. Voice Undescribed.
Text account compilers
Clark, J.
Contributors
Bowden, C., Dowsett-Lemaire, F., Fotso, R., Whytock, R., Dowsett, R.J., Bird, J., Taylor, J., Symes, A., Westrip, J.R.S., Shutes, S., Ekstrom, J. & Butchart, S.
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.