Data Zone
Justification of Red List category
This species is listed as Endangered owing to its very small range (being currently known from only two confirmed sites). The habitat at both sites is under great pressure, especially from fire.
Population justification
The total population is estimated at 2,272 individuals, thus it may lie at the lower end of the range 2,500-9,999 individuals. This range equates to 1,667-6,666 mature individuals, rounded here to 1,500-7,000 mature individuals. Mizuta et al. (2001) estimate territories of 5-8 ha, non-contiguous separated by c.200m, thus giving a 100m extra buffer around each territory. Hence an 8 ha territory takes up 24 ha. This is equivalent to 4 pairs/km2, or 8 indivs/km2. Habitat area: 20% of 1420 km2 = 284 km2. Total Population: 8 x 284 km2 = 2272 indivs. This estimate may be an optimistic minimum because the Jardin Botanique study site of Mizuta et al. (2001) is likely to have been chosen for ease of study.
Trend justification
The population is suspected to be in decline owing to the ongoing destruction and degradation of its forest habitat (ZICOMA 1999). The likely rate of decline, however, has not been estimated.
Xenopirostris damii is currently known from only two confirmed sites (Ankarafantsika and Analamera) in north-west Madagascar. However, there is much suitable habitat between the two sites that has not been thoroughly surveyed (Morris and Hawkins 1998), which may be able to hold this species (e.g. Long et al. 2012 - although the species is not listed on a further survey of this location Long et al. 2013). It is considered the island's rarest and most threatened vanga (Langrand 1990).
The species is found at low altitude only in, or adjacent to, undisturbed, dry, deciduous forest (Langrand 1990), where it forages for invertebrates in dead wood and leaf clumps (Morris and Hawkins 1998), often joining other vangas (particularly Rufous Vanga Schetba rufa) and other insectivores in mixed-species flocks (Morris and Hawkins 1998). The breeding season starts in October and extends until January at least (Morris and Hawkins 1998, Mizuta et al. 2001). Clutch size at 3-4 is large for a Xenopirostris vanga, with other congeners having two (Langrand 1990). Breeding pairs occupy widely separated, non-contiguous home ranges of 5-8 ha (Mizuta et al. 2001), suggesting approximate densities of 4 pairs/km2.
The species's habitat is declining in both extent and quality, due to the clearing and burning of forest for subsistence maize cultivation, uncontrolled bushfires, commercial logging and exploitation for charcoal and firewood (ZICOMA 1999).
Conservation Actions Underway
Both Ankarafantsika and Analamera are protected areas (National Park and Special Reserve respectively), but their long-term future is not certain (ZICOMA 1999).
23 cm. Large-billed vanga. Males have a glossy black cap and dark grey upperparts, with whitish underparts. Dark grey bill. Females and immatures are similar but cap is less extensive, with pale spots over eyes, and paler upperparts. Underparts of juveniles may be washed buffy. Similar spp. From other vangas and Ashy Cuckoo-shrike Coracina cinerea by very deep and powerful dark bill. Voice Calls tseeang very loudly. Hints Found in mixed-species flocks in dense deciduous forest, where it strips bark from dead branches, opens pupal cases and removes epiphytes with its strong bill. The noise of this debris falling aids the location of the species.
Text account compilers
Ekstrom, J., Westrip, J., Wheatley, H., Shutes, S., Starkey, M., Evans, M., Taylor, J.
Contributors
Hawkins, F., Mizuta, T. & Westrip, J.
Recommended citation
BirdLife International (2024) Species factsheet: Van Dam's Vanga Xenopirostris damii. Downloaded from
https://datazone.birdlife.org/species/factsheet/van-dams-vanga-xenopirostris-damii on 23/11/2024.
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 23/11/2024.