Data Zone
Justification of Red List category
Although this species has a small range, it is believed to occur at high densities within it and have a relatively large population size. Moreover, despite some evidence of habitat loss and degradation, O. decipiens appears to be tolerant of these habitat modifications, and there is no indication that it is currently declining. For these reasons it is listed as Least Concern.
Population justification
The global population size has not previously been quantified, but the species is described as moderately common (Coates and Bishop 1997; Eaton et al. 2016, 2021). Within this species' range, c.2,700 km2 of forest remains (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). This species was formerly considered conspecific with O. bouroensis of Buru, which has been recorded at densities of c.92-193 individuals/km2 (Poulsen 1998); applying this density to the present species, and assuming approximately 50% of forest is occupied, the population is estimated at c.125,000-250,000 individuals, or 83,000-166,000 mature individuals, rounded here to 75,000-150,000.
Trend justification
Data on population trends are lacking. Remote sensing data (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein) indicate that in the three generations to 2022, forest cover in the species' range reduced by 3-5%. However, it is described as very common 'even in heavily degraded [forest], forest edge habitat' and is reportedly one of the most regularly encountered Tanimbar endemics (J. Eaton in litt. 2023), thus habitat losses on this scale are not thought to be causing population declines. In the absence of other threats, the trend is suspected to be stable.
Oriolus decipiens is confined to the Banda Sea Islands Endemic Bird Area, Indonesia, where it occurs in the Tanimbar Islands.
This species inhabits primary and secondary forest in the lowlands, where it is is tolerant of highly modified habitats (Eaton et al. 2021, Haryoko et al. 2021, J. Eaton in litt. 2023).
Habitat loss and degradation are the key threats to this species, but these appear to be occurring at a rate too slow to cause declines in this degradation-tolerant species.
Conservation Actions Underway
No targeted conservation action is known for this species, although some of its habitat is protected.
Conservation Actions Proposed
Monitor populations and habitat trends on occupied islands.
Text account compilers
Berryman, A.
Contributors
Butchart, S., Eaton, J., Ekstrom, J. & Symes, A.
Recommended citation
BirdLife International (2024) Species factsheet: Tanimbar Oriole Oriolus decipiens. Downloaded from
https://datazone.birdlife.org/species/factsheet/tanimbar-oriole-oriolus-decipiens on 19/12/2024.
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 19/12/2024.