Justification of Red List Category
This recently split species is tentatively classified as Near Threatened, as it is suspected to have a small, declining population, approaching the threshold for Vulnerable. However, uncertainties about this species still remain, and urgent research into its ecology and status are required.
No population estimates are available for this poorly known species, but it is regularly seen and known from multiple locations. It is tentatively placed in the band of 10,000-19,999 mature individuals (equating roughly to 15,000-30,000 individuals in total). However, the true population size might be much lower.
The population is most likely patchily distributed and suspected to be in decline owing to ongoing habitat destruction and fragmentation.
Micromacronus sordidus is endemic to the island of Mindanao, the Philippines. It was previously considered conspecific with the Visayan Miniature-babbler M. leytensis, and although it is slightly better known than that species, there are few recent records. However, it is tiny and unobtrusive, and therefore may be more common than currently thought. However, the evident paucity or even lack of records from seemingly suitable sites (e.g. Pasonaca, Mt Mantalingahan, Mt Kitanglad, Mt Hilong-Hilong, Mt Talomo, Mt Tagubud) might suggest that the species is rarer and more restricted than suspected by the extent of forest cover (P. Simpson in litt. 2017, R. Hutchinson in litt. 2018). Recent sightings near Sitio Siete found the species to be locally common there, though further surveys throughout its potential range are required to confirm whether it is only locally common in this area and rare elsewhere (R. Hutchinson in litt. 2008).
The species occurs in the undergrowth and canopy of montane broadleaf evergreen forest and forest edge. It has been recorded in small, active, noisy groups; often associating with other species. The altitudinal range of the species is 600–1,670 m with most records above 1,000 m.
Within the elevation range of the species, the area of forest cover has declined only slightly within the last 10 years. After rapid forest loss during the 1990s, rates of forest loss on Mindanao slowed considerably in the 2000s, and the area of primary forest has been roughly maintained on Mindanao since 2005. Should the species be declining, as has been assumed, it is currently likely to be only at a slow or negligible rate.
Conservation Actions Underway
It is known from Mount Apo and Mount Kitanglad National Parks.
Identification. Dark, olive crown; feathers indistinctly edged with black; back, wings, and tail olive green; elongated feathers on lower back and sides white broadly edged with grey with distal half of feathers without webs. Lores yellowish-white; throat white; centre of breast and belly pale yellow; flanks olive. Bill dark horn, lower mandible lighter; eyes red; legs green-grey; toes yellow. Similar species. Lovely Sunbird Aethopyga shelleyi
which differs in having a long decurved bill and lacks long erectile feathers. Voice. Not recorded.
Text account compilers
Hermes, C., Taylor, J., Mahood, S., Westrip, J., Martin, R.
Simpson, P., Hutchinson, R.
BirdLife International (2020) Species factsheet: Micromacronus sordidus. Downloaded from http://www.birdlife.org on 16/02/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/02/2020.