Justification of Red List Category
This species is listed as Near Threatened as it is likely to be declining moderately rapidly throughout its range as a result of habitat loss. Although it is restricted to lowland areas in which rates of deforestation are highest, it is also tolerant of secondary habitats, and is therefore likely to be at reduced risk.
The global population size has not been quantified, but the species is described as generally fairly common to common although uncommon in Sumatra and rare in Singapore (del Hoyo et al. 2007).
Declines are suspected to be occurring in response to rapid and widespread deforestation across many parts of the range. This species's tolerance of secondary and logged habitats suggests that these declines may not be severe at present.
Trichastoma rostratum is known from the Sundaic lowlands, in south Tenasserim, Myanmar; peninsular Thailand; Singapore (rare); Sabah, Sarawak and peninsular Malaysia; Kalimantan (including northern islands) and Sumatra (including offshore islands), Indonesia, and Brunei. It is fairly common, though localised, throughout this range.
This species is found near water in lowland evergreen forest and secondary growth, as well as mangroves and peatswamp forest, up to 500 m. It has also been recorded in overgrown plantations, beach-strand scrub and stunted forest on islands. It is often regarded as a riverine forest specialist.
Rates of forest loss in the Sundaic lowlands have been extremely rapid, owing partly to the escalation of illegal logging and land conversion, with deliberate targeting of all remaining stands of valuable timber including those inside protected areas. Forest fires have also had a damaging effect (particularly in 1997-1998). The magnitude of these threats may be allayed by this species's tolerance of secondary growth and logged forest.
Conservation Actions Underway
Conservation Actions Proposed
Conduct repeated surveys within the range to assess its current distribution and abundance, as well as identify population trends and rates of habitat loss. Conduct ecological studies to improve understanding of its precise habitat requirements, tolerance of secondary habitats and response to fragmentation. Protect significant areas of suitable forest at key sites, in both strictly protected areas and community-led multiple use areas.
Text account compilers
Butchart, S., Gilroy, J., Khwaja, N., Mahood, S.
BirdLife International (2019) Species factsheet: Trichastoma rostratum. Downloaded from http://www.birdlife.org on 17/02/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 17/02/2019.