Data Zone
Justification of Red List category
This species is threatened on the basis of suspected continuing declines in both its small population and its small range, owing to the destruction and severe fragmentation of its lowland rainforest habitat, mainly as a result of subsistence agriculture. Climate change is also projected to greatly impact this species's ecological niche in the future, and so this species is uplisted to Endangered.
Population justification
The population is estimated to number 2,500-9,999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 3,750-14,999 individuals, rounded here to 3,500-15,000 individuals.
Trend justification
The population is suspected to be in decline owing to the clearance and degradation of forest within its range. Modelling the possible effects of climate change have shown that this species's ecological niche may completely disappear by 2050 (Andriamasimanana and Cameron 2013). Depending on when climate change begins to noticeably impact the species's habitat, this could equate to a decline in its ecological niche in the range of 50-79% over its next 3 generations (c.21 years).
Oriolia bernieri is known from many sites between Marojejy in the north and Zahamena in the centre-east of Madagascar. There is a single, as yet unconfirmed, record from Vondrozo. It is scarce and patchily distributed throughout its range.
This species is restricted to undisturbed, primary tracts of humid evergreen forest. Studies in 1988 in Marojejy found it to be remarkably localised, but fairly common in the south-west area of the reserve (Evans et al. 1992). It is found either in isolated pairs or in mixed-species flocks made up principally of vangas (Langrand 1990). It forages by searching the leaves and rooting around in the leaf-bases of pandanus Pandanus, ravenala Ravenala madagascariensis and palms, also levering rotten bark and moss off large tree-branches with its wedge-like bill, in search of large invertebrates, e.g. beetles, crickets and spiders (Langrand 1990, Evans et al. 1992).
The principal threat to the species's habitat in the primary, lowland rainforest is posed by subsistence slash-and-burn cultivation, which results in progressively more degraded regrowth and leads eventually to bracken-covered areas or grassland (Du Puy and Moat 1996). Much of the eastern coastal plain has either already been cleared or is covered by highly degraded forest (Jenkins 1987), remaining habitat is under pressure from the increasing human population (Jenkins 1987), and commercial logging is an additional threat in some areas (ZICOMA 1999). If present trends continue, the remaining forest (especially at lower altitudes) will disappear within decades (Du Puy and Moat 1996). Climate change may also prove to be an key threat in the future, as modelling has shown that this species's ecological niche may decline by 100% due to climate change over the 50 year period from 2000 to 2050 (Andriamasimanana and Cameron 2013). Assuming a linear decrease, this would equate to a c.63% decline in its ecological niche over its next 3 generations.
Conservation Actions Underway
The species is known from Ambatovaky Special Reserve, Anjanaharibe Classified Forest, Anjanaharibe-South Special Reserve, Betampona Strict Reserve, Bezavona Classified Forest, Haute Rantabe Classified Forest, Mangerivola Special Reserve, Marojejy National Park, Masoala National Park and Zahamena National Park (ZICOMA 1999). The three National Parks are particularly important for this species, as they still contain significant areas of suitable habitat (Thorstrom and Watson 1997, ZICOMA 1999).
23 cm. Medium-sized vanga. Male is glossy black all over, with a white iris and a striking, pale blue bill. Female is bright rufescent, with narrow black barring all over. Similar spp. Female is unmistakable. Male could possibly be confused with Crested Drongo Dicrurus forficatus but has pale iris and bill, and completely different behaviour. Voice Loud call, schrip-schrip-schrip, is characteristic.
Text account compilers
Shutes, S., Evans, M., Starkey, M., Symes, A., Taylor, J., Ekstrom, J., Westrip, J.
Contributors
Andriamasimanana, R., Hawkins, F.
Recommended citation
BirdLife International (2024) Species factsheet: Bernier's Vanga Oriolia bernieri. Downloaded from
https://datazone.birdlife.org/species/factsheet/berniers-vanga-oriolia-bernieri 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.