Data Zone
Justification of Red List category
This species is experiencing an ongoing decline in population size, due to the loss, fragmentation and degradation of its forest habitat from agricultural encroachment and logging activities. The rate of this decline is suspected to have been rapid over the past three generations and continue thus in the near future, and therefore the species has been assessed as Vulnerable.
Population justification
The population size of this species has not been quantified, but it is thought to be rather small; it is considered patchily distributed and quite common to scarce where it is present within its range (Schulenberg 2013, Yamagishi and Nakamura 2020). Considering this patchy distribution and its suspected sedentary nature (Yamagishi and Nakamura 2020), several subpopulations are likely present, although further study is needed to confirm this.
Trend justification
Although this species may occur in degraded or secondary forest, it only does so when these habitats are adjacent to primary intact forest (Langrand 1990, Schulenberg 2013). It is therefore considered to be highly dependent on the latter habitat, which is decreasing within its range at a rapid rate (Yamagishi and Nakamura 2020, Global Forest Watch 2024). It is therefore suspected to be decreasing, with a rate of decline which is suspected to be rapid and in step with the loss of its habitat.
Forest cover within the species’ range reduced in extent by 32-34% over the past three generations, and is projected to decrease by approximately 34-36% between 2016 and 2027 (setting 2016 as the start year on account of the fact it was the year of most rapid loss) and, based on the average annual rate of loss over the past 5 years (2018-2023) approximately 28-29% over the next three generations (Global Forest Watch 2024, using Hansen et al. [2013] data and methods disclosed therein). It is suspected that the rate of population reduction is similar to rates of forest cover loss, but the former may be greater because of the additive impacts of habitat fragmentation and degradation (this is supported by findings that show it is sensitive to habitat fragmentation, with its density decreasing in line with the size of habitat parcels (Benjara et al. 2021)). The suspected rate of decline of the population size is therefore placed in the band of 30-40% decline over the past three generations, and 35-45% between 2016 and 2027 and 25-35% over the next three generations.
This species is patchily distributed in primary humid evergreen forest throughout eastern Madagascar. It is fairly common between Andohahela and Ranomafana, from sea-level to 1,950 m, but seems to be much scarcer in the northern half of its range (Goodman et al. 1997, Hawkins and Goodman 1999). Recently, studies in northeastern Madagascar have recorded the presence of the species in Benamevika and in nearby Mahimborondro (Benjara et al. 2021, Mittermeier et al. 2021).
This species occupies the middle and upper levels of undisturbed rainforest (Langrand 1990). It may occur in secondary and degraded forest, but always near to primary forest (Schulenberg 2013). It is usually in family groups, but it often joins other large vangas in mixed-species flocks, foraging for invertebrates (e.g. caterpillars, insects and spiders) on dead wood, especially under dead bark and in twigs (Langrand 1990, Morris and Hawkins 1998, Schulenberg 2013). Nesting has been observed in October-December, and its clutch-size is two eggs.
The species' forest habitat being lost at a currently rapid rate (Global Forest Watch 2024), due to encroachment from slash-and-burn cultivation for subsistence farming and commercial logging, causing habitat degradation and fragmentation as well as loss (A. F. A. Hawkins in litt. 1995, Du Puy and Moat 1996). If these trends continue, much of the remaining forest, especially at lower altitudes, will disappear within decades (Du Puy and Moat 1996, Yamagishi and Nakamura 2020).
Conservation Actions Underway
No direct conservation action is known for this species. The species occurs in some protected areas, including the East Malagasy Wet Forests EBA, Benamevika Protected Area and Mahimborondro Protected Area (Yamagishi and Nakamura 2020, Benjara et al. 2021, Mittermeier et al. 2021)
A solid, thick-billed vanga. Males are black-hooded, with the upper breast in addition black; the underparts are whitish and the back grey. The bill is pale blue. Females are similar but the hood covers only the head and the breast is pink- or orange-tinged. Similar spp. Males are distinguished from Ashy Cuckoo-shrike Coracina cinerea and females from Tylas Vanga Tylas eduardi by the conspicuous deep pale blue bill. Hints Rather scarce, apparently most common in mid- and high-altitudes in southern Malagasy rainforest, where it may be found stripping moss off branches in mixed-species flocks. This and the next species share the characteristic Xenopirostris whistle, a loud tseeang.
Text account compilers
Rutherford, C.A.
Contributors
Evans, M., Hawkins, F., Langrand, O., Symes, A., Taylor, J. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Pollen's Vanga Xenopirostris polleni. Downloaded from
https://datazone.birdlife.org/species/factsheet/pollens-vanga-xenopirostris-polleni 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.