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

Justification of Red List category
Although this species has a small range and a relatively small population size, there are no threats acting in its range thought to be causing declines in population size, occurrence/occupancy, or habitat area. It therefore does not meet or approach either 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), the population trend criterion (>30% decline over ten years or three generations), or 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 it is assessed as Least Concern.

Population justification
The population size of this species has not been formally estimated. It was described as uncommon by Eaton et al. (2021) but inside forest in optimal habitat with a bamboo understorey, pairs can be spaced only c.200 m apart (J. Eaton in litt. 2022). Assuming this description translates to a maximum density of c.50 mature individuals/km², c.20-40% of forest within its elevational range (totalling 1,000 km²) is occupied, the population is estimated here to number 10,000-20,000 mature individuals

Trend justification
The population is suspected to be stable in the absence of evidence for any declines or substantial threats. Remote sensing data (Global Forest Watch 2022, using data from Hansen et al. [2013] and methods disclosed therein) indicate minimal (<1%) forest loss in this species' elevational range.

The species is endemic to Seram, Indonesia.

The species inhabits the undergrowth of montane forest, principally above 1,100 m, but occasionally down to 850 m (Eaton et al. 2021, J. Eaton in litt. 2022).

The only plausible threat to this species is forest loss, although this is currently occurring at a rate so slow that declines cannot be assumed. This species' preference for remote montane forests buffers it from the most extreme forest loss.

Conservation Actions Underway
None specific to this species, but occurs in Manusela National Park.

Conservation Actions Proposed
Continue to monitor forest loss data.

Text account compilers
Berryman, A.

Contributors
Eaton, J.

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Recommended citation
BirdLife International (2024) Species factsheet: Seram Grasshopper-warbler Locustella musculus. Downloaded from https://datazone.birdlife.org/species/factsheet/seram-grasshopper-warbler-locustella-musculus on 05/12/2024.
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 05/12/2024.