Justification of Red List Category
This species is classified as Endangered because it has an extremely small population occupying a very small range at only one location around an active volcano. There has been a continuing decline in the area, extent and quality of native habitat at this location, but the species's population appears to be fluctuating, and not in decline.
In 1985, it was estimated that little over 100 individuals existed, but a few more birds have since been found in the south-west (R. Demey in litt. 1999). The estimate of 100 individuals is treated as a minimum, equating to a minimum of 70 mature individuals.
This species's population appears to be always low and fluctuating (M. Louette per C. Marsh in litt. 2007), however the species survives in exotic degraded vegetation and does not appear to be declining (del Hoyo et al. 2009).
Dicrurus fuscipennis has a highly localised distribution around Mt Karthala, Grand Comoro (= Ngazidja), Comoro Islands (Louette et al. 2008), and is rare even there. The majority are thought to occur between 500-1,000 m around Nioumbadjou in the south-west, but birds have also been recorded at lower elevations down to almost sea level on the southwest coast, near Zikaledjou, Singani, the Denga-denga river bridge, Salimani and Mvouvouni. It is also found at Malakoff and Hantsangoma, and around Kourani, Tsinimouachongo, Djoumouachongo, Boboni, Mvouni and Mlima Manda (del Hoyo et al. 2009, Louette et al. 2008). In 1985, the total population was estimated at around 100 individuals, although the true figure may be slightly higher (R. Demey in litt. 1999).
It is primarily found within a 100-1150 m altitudinal zone at the lower edge of Mt Karthala forest, although it has also been found at lower elevations on the south-west coast. It appears to show a preference for forest clearings, forest edge and adjacent areas, such as plantations and fields with a well developed bush layer but few high trees, but has also been recorded in under-planted forest with a tall canopy still present, and in coconut and cacao plantations (C. Marsh in litt. 2007; del Hoyo et al. 2009). It forages singly or in pairs on large flying insects (Louette et al. 1988), and is observed singly, in pairs or in small family groups, perching relatively high in the trees, generally in a very visible post and sallying out to catch prey on the wing (del Hoyo et al. 2009). Analysis of four stomach contents revealed the consumption of beetles, grasshoppers, cockroaches and mantids, and also fruit (del Hoyo et al. 2009). The nest is a neat cup, built on a small fork at the end of an outer branch, with breeding taking place from September-December and possibly beyond (del Hoyo et al. 2009). The reasons for this species's rarity are unknown, but the fact that it occupies now mainly degraded vegetation with exotics suggests that its optimal native habitat may have already disappeared at lower altitudes and that it may now be restricted to marginal habitats (del Hoyo et al. 2009).
Most habitat has already been degraded within the known range of this species (Louette et al. 1988, Safford 2001). Since it can persist in exotic vegetation it might be expected to be abundant, and therefore the main threat to its survival is probably still unknown (R. Safford in litt. 1999, Safford 2001). It has been suggested that some localities from which it is known could be marginal habitats (Louette et al. 1988). The main threats to native forest on Mt Karthala are clearance for agriculture, invasion of exotic plant species and commercial logging on the southwest slopes. 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). Introduced rats are abundant in the forest and may predate nests; civets Viverricula indica and mongoose Herpestes auropunctatus are also potential predators (Safford 2001, del Hoyo et al. 2009).
Conservation Actions Underway
A protected area (national park, biosphere reserve or resource management area) on Mt Karthala has been proposed, but is not yet forthcoming (Louette and Stevens 1992, Safford 2001).
24 cm. Starling-sized, dark bird with long, forked tail. Unglossed brown primaries and tail contrast with otherwise all-black plumage with slightly glossy, deep blue sheen in direct sunlight. Juvenile matt blackish-brown. Black bill and legs. In flight, undersides of primaries reflect light and give false impression of having pale wing-patches. Voice Typical drongo squeaks and sharp clicks and softer wit wit note.
Text account compilers
Ekstrom, J., Pilgrim, J., Shutes, S., Symes, A., Taylor, J., Warren, B. & Westrip, J.
Demey, R., Louette, M., Marsh, C., Rocamora, G. & Safford, R.
BirdLife International (2019) Species factsheet: Dicrurus fuscipennis. Downloaded from http://www.birdlife.org on 18/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 18/11/2019.