Data Zone
Justification of Red List category
This species qualifies as Vulnerable because it is thought to have a small population given the limited area of suitable habitat available to it. It has recently been found well above its previously assumed elevational limit and is no longer thought to be restricted to river-edge habitats; however, its distribution appears to be patchy and is still inadequately known. The population is thought to be stable, but evidence of a local decline and potential threats to its habitats necessitate further research and monitoring, and if there is further evidence for declines then the species may warrant uplisting.
Population justification
The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.
Trend justification
The overall population is suspected to be stable, although it is reported that the species has deserted areas of habitat near Bombaim (F. Olmos in litt. 2007), perhaps indicating a local decline. In addition, some illegal logging had taken place recently in areas occupied by the species, with further encroachment a possibility (F. Olmos in litt. 2013).
This species is endemic to São Tomé, São Tomé e Príncipe, where it occurs in the central and southern parts of the island, excluding the central massif around the Pico de São Tomé, from the Formoso Grande and the banks of the Io Grande and Ana Chaves rivers to the valleys of the São Miguel, Xufexufe and Quija rivers (Atkinson et al. 1991, Christy and Clarke 1998). Known from only six records prior to 1928, it was rediscovered in 1990 in the valleys of the Xufexufe and Ana Chaves rivers, with recorded densities of 4.1-6.3 pairs and 5.6 pairs per km of river, respectively (Atkinson et al. 1991). These are regarded as high population densities that may not be representative of the species's range in general (R. Faustino de Lima in litt. 2013). In 1997, it was reported to be seen and heard in almost every forested river basin in the Agua Ribeira near Formoso Grande and around São Miguel (S. d'Assis Lima in litt. 1997). Once thought to be restricted to forest below 600 m, it has since been found to occur at over 1,000 m in the headwaters of the Ana Chaves river (F. Olmos in litt. 2007), and to be fairly common in some montane forests above 1,300 m (Maia and Alberto 2009, Olmos and Turshak 2010). However, overall the species seems to be relatively scarce at higher altitudes (M. Dallimer in litt. 2013); for example, in a systematic survey of primary forest sites spanning lowland, montane and mist forest, the species was only recorded in lowland areas (Dallimer et al. 2009), although it was encountered outside the formal survey periods at higher altitudes (Dallimer et al. 2003). In general, the species is said to be patchy in occurrence (F. Olmos in litt. 2013), as indicated by its apparent absence around Lagoa de Santa Amelia (R. Rocha in litt. 2013). Its population is estimated to number fewer than 1,000 mature individuals, although more investigation is required. The overall population is thought to be stable, although it is reported that the species has deserted areas of habitat near Bombaim (F. Olmos in litt. 2007), perhaps indicating a local decline.
This species appears quite common in humid forest, possibly preferring boulder strewn micro-habitats where it forages for invertebrates on rocks, moss-covered stones and fallen branches (Atkinson et al. 1991, Christy and Clarke 1998). Once thought to be restricted to lowland forest below 600 m, and associated with water, it has since been found to be fairly common in montane forests over 1,300 m, with some records coming from steep terrain, and showing no association with water in either low elevation or montane forest (Olmos and Turshak 2010). Although primarily occurring on the forest floor and lower strata, it has also been observed flying up to the mid-storey in ridgetop forest (N. Borrow in litt. 2003).
Historically, large areas of lowland and mid-altitude forest were cleared for cocoa and coffee plantations. Today, land privatisation is leading to an increase in the number of small farms and the clearance of trees. This does not generally affect primary forest, but may be a threat in the future (Christy and Clarke 1998). Former commercial plantations were ceded to an international oil-palm producing company in 2009, who apparently plan to restore c.2,000 ha of plantations on the south coast, potentially either reducing hunting and other pressures on the forest through creating local employment, or alternatively increasing impacts as people move to the area in search of work (Olmos and Turshak 2010). Recent clearing of secondary growth and abandoned oil-palm plantations to plant new oil-palm has resulted in illegal logging in areas occupied by the species, such as Monte Carmo, with resulting loss of habitat quality and potential for further encroachment (F. Olmos in litt. 2013). The species has apparently abandoned areas of habitat near Bombaim, after the locality began to be heavily used for harvesting palm-wine, resulting in the presence of many people (F. Olmos in litt. 2007). Road developments along the east and west coasts are facilitating access to previously remote areas (A. Gascoigne in litt. 2000). The introduced Black Rat Rattus rattus and weasel Mustela nivalis are potential predators of adults and nests (F. Olmos in litt. 2007). Construction for the country's developing oil industry, including the established idea of building 'free ports' (free economic zones) (M. Melo in litt. 2003), was seen as a potential threat to the species's habitat. However, prospecting on land was unsuccessful, and any construction is likely to be offshore (F. Olmos in litt. 2007).
Conservation Actions Underway
A new law providing for the gazetting of protected areas and the protection of threatened species (A. Gascoigne in litt. 2000, M. Melo in litt. 2003) has been ratified (F. Olmos in litt. 2007). Legislation for the creation of Obo National Park has also been ratified (F. Olmos in litt. 2007) and protection of primary forest as a zona ecologica has been proposed.
10 cm. Small, long-legged, short-tailed, forest bird. Dark brown head with very faint pale stripe behind eye. Pale chin, dark brown back, orange-brown underparts becoming paler on belly and flanks. Dark brown wings with some orange-brown fringing to coverts. Black axillaries. Long, thin, bill. Long, pale flesh-coloured legs. Voice Thin, far-carrying tseeeep whistles and tsuuit contact calls.
Text account compilers
Benstead, P., Shutes, S., Starkey, M., Ekstrom, J., Symes, A., Taylor, J., Westrip, J., Peet, N.
Contributors
Olmos, F., Jones, P., d'Assis Lima, S., Borrow, N., Faustino de Lima, R., Gascoigne, A., Dallimer, M., Melo, M., Rocha, R.
Recommended citation
BirdLife International (2024) Species factsheet: Sao Tome Shorttail Amaurocichla bocagii. Downloaded from
https://datazone.birdlife.org/species/factsheet/sao-tome-shorttail-amaurocichla-bocagii on 23/12/2024.
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 23/12/2024.