Data Zone
Justification of Red List category
This species has a very small range that is under severe pressure from deforestation and forest degradation. These threats are increasing, deforestation is accelerating and much of its remaining habitat could be cleared in the near future. The species is therefore listed as Vulnerable.
Population justification
The world population was thought to be in the range of c.2,500-5,000 mature individuals, however in 2005 the species was discovered on Mt Mabu in Mozambique, where the population is conservatively suspected to number c.2000 mature individuals (1,000-1,500 pairs [Spottiswoode et al. 2008, Dowsett-Lemaire and Dowsett 2009, Bayliss et al. 2014]), and there are other areas of this country that could hold the species. Thus on the basis that further exploration is required before a reliable estimate of the total population can be made, the overall population is placed in the range bracket 2,500-9,999 mature individuals.
Trend justification
The population is suspected to be declining very rapidly in Malawi in line with the extensive clearance and degradation of highland forests there, and to a lesser degree in Mozambique, with a substantial proportion of the known population occurring on Mt Mabu where there is currently relatively low pressure on the forest. However, deforestation analysis by Tracewski et al. (2016) estimated an annual decline in forest cover within this species’s range to be c.0.2% between 2000 and 2012, which would roughly equate to a decline of 4.5% over three generations (c.20 years). Further substantial populations may occur in intact forests in unsurveyed areas of Mozambique (Spottiswoode et al. 2008), which, if found to be the case, would have a bearing on the overall proportion of the population that is decreasing and thus the overall rate of decline. Therefore, the overall rate of decline is uncertain.
Chamaetylas choloensis is known from 16 areas of forest, 13 of them in south-eastern Malawi (east of the Shire river), plus four in adjacent Mozambique (Mts Namuli [Keith et al. 1992], Chiperone [Keith et al. 1992, Spottiswoode et al. 2008], Mabu [Spottiswoode et al. 2008], and Inago [Bayliss et al. 2010, Fishpool and Bayliss 2010]). Tracewski et al. (2016) estimated the maximum Area of Occupancy (calculated as the remaining tree area within the species’s range) to be c.1,360 km2. The species probably occurs on mountains between Mts Namuli and Mabu (F. Dowsett-Lemaire in litt. 2008). Its world population was thought to be in the range of c.2,500-5,000 mature individuals. However, in 2005, the species was discovered on Mt Mabu, where the population is described as common above 1,200 m and conservatively suspected to number c.2,000 individuals, or possibly 1,000-1,500 pairs (Spottiswoode et al. 2008, Dowsett-Lemaire and Dowsett 2009, Dowsett-Lemaire 2010, Bayliss et al. 2014).
In Malawi, there were c.1,500 pairs in 1983, mostly on Mt Mulanje (1,000 pairs) and Mt Thyolo (200 pairs) (Dowsett-Lemaire 1989), but the population has almost certainly decreased since then (F. Dowsett-Lemaire in litt. 1997, 2000, P. Kaliba and L. Luhanga in litt. 2003). Recent reports (2003) suggest that the Malawi population is now confined to five areas and that two historical sites (including Thyolo) have been lost to encroachment by agriculturalists (P. Kaliba and L. Luhanga in litt. 2003, Spottiswoode et al. 2008). The most important remaining populations in Malawi are likely to be in the wet forest on Chikala Hill in Liwonde forest reserve, the wet forest on the summit of Mangochi Mountain forest reserve, and in the Ruo and Chisongeli forests on Mt Mulanje (F. Dowsett-Lemaire per Spottiswoode et al. 2008, J. Bayliss in litt. 2016). Although c.1,000 pairs were estimated on Mt Namuli in 1998 (Ryan et al. 1999) these figures may be far too high, and Dowsett-Lemaire (2010) estimated <50 pairs for Namuli, excluding the unexplored plateau south of the Malema River. In November 2007, the species was recorded as reasonably common in Ukalini Forest (Mt Namuli), at c.2 pairs/10 ha (Dowsett-Lemaire 2010). The population in Manho Forest (Mt Namuli) was estimated at 'a few dozen pairs' in 2007 (F. Dowsett-Lemaire in litt. 2008). On Mt Chiperone, the population is conservatively suspected to number c.800 individuals (Spottiswoode et al. 2008). On Mt. Inago the situation is very serious with widespread deforestation; and there are only an estimated <50 pairs (J. Bayliss in litt. 2016).
It is a terrestrial bird of submontane evergreen forest, and breeds at mid-altitudes (mainly above 1,200 m, but some as low as 950 m on Mabu), but can occur lower in the non-breeding season (March-October) (Dowsett-Lemaire 1989). Its population density is closely tied to the presence of ant nests. Pairs can persist in forest patches as small as 0.5 ha if there is an ant nest, but the density is usually much lower (F. Dowsett-Lemaire in litt. 1997, 2000).
Deforestation at its sites in Malawi is intense; between the 1970s and early 1990s, at least three of its localities were completely cleared, e.g. the 40 km2 Chisongeli Forest (Mt Mulanje) (Dowsett-Lemaire 1989, F. Dowsett-Lemaire in litt. 1997, 2000). Deforestation of Chisongeli Forest had stabilised at c.1,600 m in 2007, with nearly all forest cleared below this altitude, and only c.20 km2 remaining between 1,600 and 2,000 m (F. Dowsett-Lemaire in litt. 2008). During 1995-1996, severe fires destroyed much of its habitat at Lisau (Mt Chiradzulu) as well as parts on Zomba (F. Dowsett-Lemaire in litt. 1997, 2000) which hold the second largest population of this species (J. Haugaard in litt. 2003). Over the period 1999-2003, Thyolo Forest Reserve was completely cleared for subsistence agriculture, reducing forest on the mountain to a single small fragment on private land (Spottiswoode et al. 2008). Soche Mountain has lost 30-40% of its remaining mist-belt forest (J. Haugaard in litt. 2003, P. Kaliba and L. Luhanga in litt. 2003) and forest at Ndirande was completely cleared in the 1990s (F. Dowsett-Lemaire in litt. 2006). During the late 1990s, selective logging started at Mt Namuli, and a road passing close to the summit was being built, which was expected lead to large-scale forest exploitation from the densely-populated lower slopes (V. Parker in litt. 1998), however, this road has since become impassable (J. Timberlake in litt. 2016). In November 2007, it was noted that the extent of mid-altitude forest on the eastern slopes of Mt Namuli was in decline and that suitable habitat for the species was almost gone (F. Dowsett-Lemaire in litt. 2008). The threats on Mt Namuli include fires and encroachment by settlements. Limited encroachment (c.5 ha in November 2007) of Ukalini Forest has taken place, small areas of Manho Forest have been cleared for cultivation, and both Ukalini and Manho Forests are threatened by the extraction of Faurea wentzeliana for the trade in construction material. The gaps left by such extraction are detrimental to the species, as it requires a shaded understorey (F. Dowsett-Lemaire in litt. 2008). Encroachment by subsistence farmers expected to occur on Mt Chiperone in the near future (V. Parker in litt. 1998, J. Timberlake in litt. 2016), although this may slow at higher altitudes because of steep terrain and local spiritual beliefs (Spottiswoode et al. 2008). At Mt Mabu, commercial tea farming was reported to resume on abandoned tea estates at low altitudes, and this could have led to a human population influx (Spottiswoode et al. 2008, Bayliss et al. 2014), however the forest is currently under much less pressure than at Namuli (Dowsett-Lemaire 2010), and tea farming has not yet resumed (J. Timberlake in litt. 2016). There will soon be very little habitat remaining for the species across its range (F. Dowsett-Lemaire in litt. 1997, 2000, J. Haugaard in litt. 2003, P. Kaliba and L. Luhanga in litt. 2003), with the situation at Mt Inago being serious, as forest patches are estimated at <10km2 (Bayliss et al. 2010, Fishpool and Bayliss 2010).
Conservation Actions Underway
Several sites in Malawi are Forest Reserves, but in reality this provides negligible protection. Forest on Mt Namuli, Mt Inago and Mt Chiperone is not protected, although efforts were underway in early 2008 to protect some of this habitat (F. Dowsett-Lemaire in litt. 2008).There are some conservation initiatives on Mt Mabu but they are not getting much traction yet (J. Timberlake in litt. 2016). If access to Mt Namuli improves, it is a potential site for ecotourism-based conservation (K. Barnes in litt. 1998), and it may be recognised as some kind of protected area in the future (J. Timberlake in litt. 2016). The main stronghold in Malawi of this near-endemic is undoubtedly Mulanje Mountain, which is now the centre of a major GEF programme which will hopefully ensure the survival of the mist-belt forests circling the mountain (J. Haugaard in litt. 2003).
16 cm. Small, thrush-like bird of forest undergrowth. Warm rusty upperparts. White underparts, with grey wash on sides of face and neck. White tips to outer tail-feathers. Long, flesh-coloured legs and toes. Similar spp. White-chested Alethe A. fuelleborni lacks white tail-spots and does not occur near this species. Voice Soft trrrp alarm call. Soft, melodic song. Hints Hops on leaf-litter. It usually feeds at ant-swarms, catching small arthropods flushed by ants (Dowsett-Lemaire 1989). The only documented nest was 4 m up in the fork of a tree (Keith et al. 1992). Inferred egg-laying dates range from September to January (Keith et al. 1992).
Text account compilers
Ekstrom, J., Shutes, S., Benstead, P., Starkey, M., Symes, A., Taylor, J., Westrip, J., Evans, M.
Contributors
Kaliba, P., Bayliss, J., Timberlake, J., Barnes, K., Luhanga, L., Dyer, M., Parker, V., Dowsett-Lemaire, F., Haugaard, J.
Recommended citation
BirdLife International (2024) Species factsheet: Thyolo Alethe Chamaetylas choloensis. Downloaded from
https://datazone.birdlife.org/species/factsheet/thyolo-alethe-chamaetylas-choloensis 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.