VU
Loango Weaver Ploceus subpersonatus



Justification

Justification of Red List Category

This is a rare and little-known species. It has very specific habitat requirements, and its habitats are experiencing a continued loss and degradation. Its population size is estimated to be small, hence this species is classified as Vulnerable.

Population justification

As this species is described as uncommon to rare, taking the lower quartiles of density estimates of eight congeners, including the Southern Masked-weaver Ploceus velatus of 2-3 individuals/sqkm (BirdLife Population Density Spreadsheet; Vernon 1985; Dean 1995; Monadjem 2002), and assuming it inhabits 10% of the forest within its range (17,300 sqkm [Global Forest Watch 2021]), the population is estimated to fall in the band 3,460-5,190 individuals. This is roughly equivalent to 2,306-3,460 mature individuals rounded here to 2,300-3,500 mature individuals. 

Trend justification
This species is inferred to be declining due to the ongoing loss and degradation of its mangrove and forest habitats (Okanga-Guay et al. 2019; Global Forest Watch 2021). Between 2000-2019, this species experienced forest cover loss of 5.3% (Global Forest Watch 2021), which equates to a rate of loss of 2.8% over 10 years. Adjonina et al. (2014) report that during the last 2 decades prior to 2014, mangroves in West and Central Africa were degraded or reduced by 20-30% due to pollution and over-exploitation. Assuming that this is still occurring at the same rate, the rate of decline may be 10-16% over 10 years. This species is not entirely dependent on mangrove forests, so the past rate of decline is suspected to fall in the band of 1-19%. Between 2016-2019, this species experienced forest cover loss of 1.6% throughout its range (Global Forest Watch 2021). This would equate to a loss of 4% when projected forward 10 years from 2016. The suspected future decline is therefore placed in the 1-10% band.

Distribution and population

Ploceus subpersonatus is known from the coastal strip from Gabon, Congo and the Democratic Republic of Congo into Cabinda (Angola). It has only recently been discovered in the Congo at two small coastal swamps, including one on the edge of Pointe-Noire (Bulens and Dowsett 2001). Throughout its range it is rare and occurs at low densities (P. Christy in litt. 1999, Dean 2000).

Ecology

In coastal Cabinda, it is found in rank grass in clearings in secondary forest and at the edge of marshes (Dean 2000). It inhabits mangrove forests (Craig and Juana 2020). In Gabon, it appears to be confined to coastal savanna, between coastal mangrove forest and forest inland, nesting in palms Phoenix reclinata or Caesalpinia bonduc and has apparently adapted to secondary habitat, including vegetation surrounding small coastal villages (P. Christy in litt. 1999). It is generally found within 3 km of the coast (Fry and Keith 2004) but is recorded further inland along major rivers such as Boma in Cabinda, 75 km up the Congo River. There is evidence that this species can breed in suburban areas: a nest was found under construction in July, juveniles have been observed in October, and a pair were seen leaving another nest in December (Passavy 2011). 

Threats

In Gabon, coastal bush around Port Gentil and Cap Lopez is being converted into allotments. There is potential danger from oil-spills from offshore rigs (W. R. J. Dean in litt. 1999) which may be set to increase due to new oil interests in the area, particularly from US companies (J. Ekstrom in litt. 2003). Adjonina et al. (2014) report that during the last two decades prior to 2014, mangroves in West and Central Africa were degraded or reduced by 20-30% due to pollution and over-exploitation. 

Conservation actions

Conservation Actions Underway
Its habitat is protected in the south of Gabon (P. Christy in litt. 1999). A proposal to protect the mangroves north-east of Libreville (Akanda area) would safeguard the colonies found there (P. Christy in litt. 1999). Habitat along the Cabinda coast is well protected (W. R. J. Dean in litt. 1999).

Conservation Actions Proposed
Conduct surveys to determine the distribution of the species (for example, at Conkouati, Congo, where habitat is suitable) and assess its numbers. Study the species's habitat requirements using data from population and distribution surveys. Monitor the destruction of suitable habitat within its range. Assess the threat from oil-spills and employ measures to mitigate such an event. Increase the area of suitable habitat that has protected status, including mangroves north-east of Libreville.

Identification

12 cm. Small weaver. Male has black mask which extends onto throat and upper breast in a point. Rich golden-yellow nape, sides of neck and breast with warm, orangey-brown tinges on breast and belly. Olive-yellow mantle and wings and olive-brown tail. Female similar orangey-brown below with more yellow on forehead. Voice Normal weaver-like squizzles and chipping notes.

Acknowledgements

Text account compilers
Clark, J.

Contributors
Alexander-Marrack, P.D., Benstead, P., Christy, P., Dean, R., Dowsett, R.J., Dowsett-Lemaire, F., Ekstrom, J., Pilgrim, J., Sargeant, D.E., Shutes, S., Symes, A., Taylor, J. & Westrip, J.R.S.


Recommended citation
BirdLife International (2022) Species factsheet: Ploceus subpersonatus. Downloaded from http://www.birdlife.org on 25/01/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/01/2022.