Justification of Red List category
This species is classified as Vulnerable since it has a restricted range, occurring at only one location, an active volcano. The species may be driven towards extinction in a very short time if plans to build a road to Mt Karthala's crater are resurrected.
Population justification
The population size is suspected to fall into the band 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.
Trend justification
The population is suspected to be slowly declining owing to on-going habitat loss and degradation and the effects of introduced species (Safford & Hawkins 2013). Deforestation rates have been low over the past 10 years, amounting to 1.7% (Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). Given that the species can tolerate open and shrubby areas, any population decline is likely to be slower than this. The effects of introduced taxa may further contribute to declines, but the overall decline is suspected to not exceed 10% over 10 years.
Humblotia flavirostris occurs only on the slopes of Mt Karthala, an active volcano, on Grand Comoro (= Ngazidja) in the Comoro Islands.
This insectivorous species is present throughout forest on Mt Karthala over a wide altitudinal range (Louette and Stevens 1992, Louette 2004, Louette et al. 2008). It is limited to areas with remaining tall trees but seems tolerant of shrubby, cultivated or open areas in the forest - it has even been observed in pure Philippia tree-heath above the forest belt (Louette and Stevens 1992). The nest is a cup in the upper branches of a 12-15 m high tree in pioneer woodland with at least two young (Herremans et al. 1991). Breeding was observed from October to December (Herremans et al. 1991, Louette 2004).
With this island's large, increasing human population (Herremans et al. 1991), the major threat to this species is the clearance of forest for agriculture. Since 1983, intact forest may have declined by over 25% as agriculture has advanced steadily up the slopes of Mt Karthala. However, remote sensing data indicate a loss of just 1.7% of forest in the last 10 years (Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). Secondary forest in the agricultural belt is dominated by exotic plants, particularly strawberry guava Psidium cattleianum, which could spread into and degrade remaining native forest. Commercial logging occurs in a 50 km2 concession on the south-west slopes. The tree-heath zone is threatened by browsing cattle and by fire used to stimulate growth of palatable shoots. Introduced rats and Common Myna Acridotheres tristis may act as nest predators. If plans to build a road to Mt Karthala's crater are resurrected, exploitation and fragmentation of the forest, and the spread of exotic species, could be accelerated (Safford 2001).
Conservation Actions Underway
A protected area (national park, biosphere reserve or resource management area) on Mt Karthala has been proposed, but has not yet materialised (Louette et al. 1988, Safford 2001).
14 cm. Small, dark-capped and streaked forest flycatcher. Upperparts brownish with white edgings to secondary coverts. Crown heavily striped and appears as dark cap in the field. Underparts buffy, heavily overlaid with dark brown streaking. Yellowish-orange bill and legs. Voice Soft, sharp trill. Hints It flycatches from the lowest branches of small trees or bushes, often feeding in small parties of two or three, but has never been seen in mixed-species flocks (Louette and Stevens 1992).
Text account compilers
Haskell, L.
Contributors
Ekstrom, J., Louette, M., Pilgrim, J., Safford, R., Shutes, S., Symes, A., Taylor, J., Warren, B. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Humblot's Flycatcher Humblotia flavirostris. Downloaded from
https://datazone.birdlife.org/species/factsheet/humblots-flycatcher-humblotia-flavirostris on 10/12/2024.
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 10/12/2024.