NT
Tanimbar Flycatcher Ficedula riedeli



Justification

Justification of Red List category
This species has a small range and extent of occurrence, within which there is evidence of a continuing decline in area of occupancy, habitat extent and quality, and, because of forest loss on the periphery of its range, extent of occurrence. Increasingly habitat losses in interior forests are being lost and degraded, especially on Yamdena. For now there is no evidence that the species is confined to a limited number of locations, and hence approaches, but does not meet, the thresholds for threatened under Criterion B. Accordingly is is assessed as Near Threatened. For now there is no evidence that the species is declining very rapidly, nor that it has a small population size, although both factors should be monitored closely.

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. 2,600 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 F. dumetoria, which has been recorded at densities of c. 30 individuals/km2 (Fogden 1976); applying this density to the present species, and assuming approximately 50-100% of forest is occupied, the population is estimated at c. 39,000-78,000 individuals, or c. 25,000-50,000 mature individuals. These numbers, however, require confirmation with species-specific data.

Trend justification
Data on population trends are lacking but moderate declines are suspected on the basis of ongoing forest loss. 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 c. 7%. This species is considered forest dependent (Haryoko et al. 2021), and these forest losses are suspected of having had a broadly similar (5-12%) reduction in the species' population size, with degradation also a potential additive risk for this species given its preference for darker areas of forest. Forest cover loss appears to be ongoing and the same rate is therefore projected into the future.

Distribution and population

Ficedula riedeli is confined to the Banda Sea Islands Endemic Bird Area, Indonesia, where it occurs in the Tanimbar Islands.

Ecology

This species inhabits primary and secondary forest in the lowlands (Eaton et al. 2021, Haryoko et al. 2021).

Threats

Habitat loss and degradation is the key threat to this species and is suspected of causing slow but significant declines. Across its range, forest cover extent reduced by 7% in the ten years to 2022 (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). Of particular concern, in the north-centre of Yamdena, are logging tracks that now infiltrate into the interior of the island (Google Earth 2022). Most of these losses are suspected to refer to small-holder farming and agricultural incursions, but logging tracks could indicate larger-scale, plantation-style incursions in the future.

Conservation actions

Conservation Actions Underway
No targeted conservation action is known for this species, although some of its habitat is protected.

Conservation Actions Proposed
Estimate the species' population size and the rate at which it is declining. Monitor populations and habitat trends on occupied islands. Conduct ecological studies to improve understanding of its precise habitat requirements, tolerance of secondary habitats and response to fragmentation. As a precaution, protect significant areas of suitable forest, in both strictly protected areas and community-led multiple use areas.

Acknowledgements

Text account compilers
Berryman, A.

Contributors
Martin, R., Khwaja, N., Butchart, S., Westrip, J.R.S. & Bird, J.


Recommended citation
BirdLife International (2024) Species factsheet: Tanimbar Flycatcher Ficedula riedeli. Downloaded from https://datazone.birdlife.org/species/factsheet/tanimbar-flycatcher-ficedula-riedeli 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.