Justification of Red List category
This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size has not been quantified, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Population justification
The global population size has not been quantified, but the species is described as fairly common in western and southwestern Madagascar (Morris and Hawkins 1998, Eguchi et al. 2001).
Trend justification
This species is suspected to be declining as a result of habitat loss and degradation. The species' range lost 18% of forest cover over the past three generations (11.55 years), and tree cover loss has been accelerating since 2016 to a rate equivalent to 23% (Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). As the species prefers relatively open habitats, forest cover loss alone is unlikely to drive a rapid population decline and therefore, the rate of decline over the past three generations is tentatively placed in the band 10-19%.
This species is endemic to Madagascar, from the northwest to southwest of the island (Eguchi et al. 2001).
This species occurs in open spiny forest, dry deciduous forests, and local patches of rainforest and mangrove (Eguchi et al. 2001), and is common across a range of primary and degraded habitats (F. Hawkins in litt. 2022). It forages by probing the bill into cracks on trunks and branches of large trees (Nakamura et al. 2004).
Deforestation is the main threat to this species (Eguchi et al. 2001). Tree cover loss has been accelerating since 2016 to a rate equivalent to 23% over three generations (Global Forest Watch 2021, using Hansen et al. [2013] data and methods disclosed therein). The species' habitats have been experiencing slash-and-burn agriculture and charcoal production, with only fragments of forest remaining in many western and southwestern parts of Madagascar (Eguchi et al. 2001).
Conservation Actions Underway
The species occurs in a number of protected areas, including Ankarafantsika National Park.
Conservation Actions Proposed
Survey its population density across its range. Study the species' tolerance to habitat alteration.
Text account compilers
Rotton, H.
Contributors
Butchart, S., Ekstrom, J., Hawkins, F. & Westrip, J.R.S.
Recommended citation
BirdLife International (2024) Species factsheet: Sickle-billed Vanga Falculea palliata. Downloaded from
https://datazone.birdlife.org/species/factsheet/sickle-billed-vanga-falculea-palliata on 22/11/2024.
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 22/11/2024.