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Helmet Vanga Euryceros prevostii



Justification

Justification of Red List Category
This species has a small range, restricted to north-eastern Madagascar, where its lowland forest habitat is being cleared rapidly for subsistence agriculture and timber. Climate change is projected to severely affect this species, therefore, the it has been uplisted to Endangered.

Population justification
The population size is preliminarily estimated 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. However, the population size is now potentially lower (M. Rabenandrasana in litt. 2017).

Trend justification
The population is suspected to be declining in line with the clearance and degradation of lowland rainforest within the range. Modelling the possible effects of climate change have shown that this species's ecological niche may nearly completely disappear due to climate change over the 50 year period from 2000 to 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 (21 years).

Distribution and population

Euryceros prevostii is restricted to the northern part of the humid evergreen forests of eastern Madagascar, from Tsaratanana south to Mantadia in the centre-east (ZICOMA 1999). The species is only known from primary forest, generally below 800 m, where it is uncommon (Langrand 1990) and patchy in distribution.

Ecology

It is a bird of primary, mainly lowland rainforest, occupying the middle stratum in areas with large trees (ZICOMA 1999), often occurring in mixed-species groups with other vangas (Vangidae) (Morris and Hawkins 1998). It feeds on large insects and other invertebrates, sally-gleaning from branches and trunks as well as from the ground (Morris and Hawkins 1998).

Threats

Low-altitude forest in Madagascar is a critically threatened habitat, largely due to clearance for shifting agriculture but also owing to commercial exploitation of timber (Du Puy and Moat 1996). The species's inability to survive outside this habitat puts it at risk, and climate change could cause large declines as it threatens the species's ecological niche (Andriamasimanana and Cameron 2013).

Conservation actions

Conservation Actions Underway
This species is known from the following protected areas: Ambatovaky Special Reserve, Anjanaharibe Classified Forest, Anjanaharibe-South Special Reserve, Betampona Strict Reserve, Bezavona Classified Forest, Haute Rantabe Classified Forest, Mantadia National Park, Marojejy National Park, Masoala National Park, Tsaratanana Strict Reserve and Zahamena National Park (ZICOMA 1999).

Conservation Actions Proposed
Conduct surveys in order to assess the population size. Compare population data from protected and unprotected habitat (M. Rabenandrasana in litt. 2007). Once a baseline population estimate has been obtained, carry out regular surveys to monitor population trends. Compare population trends in protected and unprotected habitat (M. Rabenandrasana in litt. 2007). Monitor rates of forest clearance and degradation. Determine its home-range size and its dispersal capability across deforested areas, in order to clarify the impact of forest fragmentation on its population structure. Improve awareness of conservation and the implications of widespread forest loss among local people.

Identification

28-31 cm. Very distinctive, large, deep-billed vanga. Black, with massive, pale blue bill, and chestnut mantle, rump and central tail feathers. Juvenile is mixture of dark and pale brown with pale brown bill. Similar spp. Difficult to confuse with any other species. Voice Sometimes detected by call, a fluty, descending pepepepewpew. Hints Rather secretive and difficult to find, as often sits immobile in subcanopy for long periods. Most conspicuous when flying at prey.

Acknowledgements

Text account compilers
Evans, M., Starkey, M., Symes, A., Taylor, J., Ekstrom, J., Westrip, J., Robertson, P.

Contributors
Rabenandrasana, M.


Recommended citation
BirdLife International (2022) Species factsheet: Euryceros prevostii. Downloaded from http://www.birdlife.org on 07/12/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 07/12/2022.