Justification of Red List Category
This species has been downlisted from Near Threatened because its range is estimated to be larger than previously thought. It is now listed as Least Concern on the basis that it is not thought to approach the thresholds for Vulnerable under any of the Red List criteria.
The global population size has not been quantified, but the species is described as locally common (Clement et al. 1999).
The species's population is assumed to be in decline, owing to the declining extent and quality of its habitat.
Estrilda thomensis was originally described in error as being from the island of São Tomé but is in fact restricted to south-western Angola (Namibe Province, north and east to south-western Huila Province and north to Fazenda do Cuito in Huambo) (Dean 2000) and extreme north-western Namibia (up to 50 km from the lower Cunene or Kunene River) (Harrison et al. 1997, C. Hines in litt. 2005). Overall, it has a large Extent of Occurrence of 95,400 km2. It is rare in Namibia, probably numbering fewer than 2,000 birds in total (Simmons and Brown 2006).
In Angola, it is locally common to frequent in thornbush, scrub, open mopane woodland and riverine Acacia woodland from 200-500 m (Clement et al. 1993, Dean 2000). In Namibia, it is restricted to mopane and riverine woodlands of the Cunene River system and its drainages, being rare in Acacia woodland (Fry and Keith 2004). It is apparently resident in Angola, but subject to substantial local movements in Namibia after rain. It feeds on grass seeds and other small seeds, flowers, insects and possibly nectar. Nest-building in Namibia has been noted in late November to December, after the first rains. Its nest in captivity has been described as a large ball of grass and coconut fibres with a narrow, down-sloping entrance tube. Two clutches of 3-4 eggs may be laid. The incubation period is 12.5-14 days, followed by a fledging period of 17-21 days (Fry and Keith 2004).
The species's habitat is generally threatened by habitat degradation caused by overgrazing and trampling by cattle and goats (C. Hines in litt. 2005, Simmons and Brown 2006), and clearance (often using fire) for subsistence agriculture. More pastoral agriculturalists are likely to be attracted by the permanent water that the proposed dam would produce (Simmons and Brown 2006). Increases in human inhabitation at springs and small tributaries south of Cunene River, with associated wood-cutting, over-grazing and over-utilisation of water, is seen by some as a greater threat than direct habitat destruction by the dam (Fry and Keith 2004). The proposed development of a hydroelectric plant on the Cunene River at Epupa Falls threatened the species's survival in Namibia; covering around half of the species's habitat in the country and - by altering river dynamics - probably changing insect biodiversity relied on by the species during feeding of young (Harrison et al. 1997, Simmons and Brown 2006). The project would also have removed habitat on the Angolan side (R. Simmons in litt. 1999). Opposition to development at this site resulted the original proposal being abandoned in 2008 and led to a new proposal to dam the river c40km downstream of Epupa Falls at Baynes, which was also opposed by local people and was still undergoing consultation in late 2011 (Anon 2011).
Conservation Actions Underway
In Angola the species occurs in Iona National Park and possibly also Chimalavera Regional Nature Park, as well as in proposed protected areas at Chongoroi and Tundavala (Dean 2001).
Text account compilers
O'Brien, A., Pilgrim, J., Robertson, P., Symes, A. & Taylor, J.
Hines, C. & Simmons, R.
BirdLife International (2019) Species factsheet: Estrilda thomensis. Downloaded from http://www.birdlife.org on 15/12/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 15/12/2019.