• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Justification of Red List category
This species is associated with forest habitat, which is being cleared within its small range. However, this is not yet severely fragmented, and the species not restricted to few locations. For these reasons, the species is classified as Near Threatened.

Population justification
The abundance and habitat associations of this species have been subject to some confusion. It is widely considered uncommon or rare (White and Bruce 1986, del Hoyo et al. 2006, Eaton et al. 2021), and Jones et al. (1995) failed to detect it at all at their point count stations (n=556; although many of these were not positioned in suitable habitat/elevation). However, it has since been observed at no fewer than 13 distinct blocks of forest (eBird 2023) and can therefore be considered likely to occur widely in suitable habitat, albeit at a low density. In total, c.2,000 km² of forest remains on Sumba (per Global Forest Watch 2023), but much of this is so heavily degraded that even a secondary forest-tolerant species such as this occurs in probably only a small percentage of this. Precautionarily, therefore, the species is suspected to number somewhere between 5,000 and 15,000 mature individuals, which assumes a somewhat arbitrary combined density/occupancy rate of  2.5-7.5 mature individuals/km². This estimate is considered to be of poor data quality and in some respects highly precautionary—a more refined estimate (as called for nearly 30 years ago by Jones et al. 1995) should be a key research priority.

Trend justification
The only identified threat to this species is habitat loss and degradation. In the ten years to 2022, forest cover on Sumba declined by c.5% (Global Forest Watch 2023, based on data from Hansen et al. [2013] and methods disclosed therein). Although this species is tolerant of edge habitat and lightly degraded forest (Eaton et al. 2021) this is considered to be the minimum rate of population reduction. This is because (1) habitat loss appears has been greatest in the island's lowlands, where this species is commonest; and (2) habitat degradation is suspected to have nonetheless had some impact. Consequently, Muscicapa segregata is suspected of having declined by 5-10% between 2012 and 2022, and precautionarily the same rate is suspected to occur in the future.

Muscicapa segregata (split from Asian Brown Flycatcher M. dauurica) is restricted to Sumba, Indonesia.

It occupies lowland primary forest, including forest edges bordering cultivation, and secondary forest from sea-level to 500 m (Eaton et al. 2021). It forages on insects in the understoreys of forest and pursues insects in flight. It is usually solitary, spending long periods sat unobtrusively on a perch.

Ongoing habitat clearance through agricultural expansion and subsistence logging represent the main threats to this species, which is suspected of having lost >5% of suitable habitat between 2012 and 2022 (per Global Forest Watch 2023).

Conservation Actions Underway
None targeting this species is known. Projects in 1989 and 1992 assessed population sizes, status and habitat associations of range-restricted species on Sumba (see Jones et al. 1995) but they failed to document this species. It is known (eBird 2023) to occur in Sumba's two terrestrial protected areas documented by UNEP-WCMC and IUCN (2023): Manupeu Tanadaru and Laiwangi Wanggameti. There are efforts (post 2015) to try and reforest some areas of Sumba via agroforestry projects that may benefit this species. For example, the Indigenous Kaliwu Agroforestry System (IKAS) has proven successful locally in planting native species that are congruent with biodiversity conservation objectives and farmers' livelihoods (see Njurumana et al. 2021).

Conservation Actions Proposed
Protect remaining areas of lowland forest. Enforce restrictions on agricultural encroachment and logging within such protected areas. Continue and expand agroforestry schemes and monitor their effectiveness for Muscicapa segregata and other Sumba endemic species. Generate density estimates to inform a revised population estimate for the species. Continue to estimate population trends by calculating rates of forest loss within its range using satellite imagery and remote sensing techniques.

Text account compilers
Berryman, A.

Contributors
Bird, J., Butchart, S. & Khwaja, N.

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Recommended citation
BirdLife International (2024) Species factsheet: Sumba Brown Flycatcher Muscicapa segregata. Downloaded from https://datazone.birdlife.org/species/factsheet/sumba-brown-flycatcher-muscicapa-segregata on 22/12/2024.
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 22/12/2024.