Justification of Red List category
Tree cover loss through conversion of forest to agriculture (particularly for oil palm plantations) is estimated at 15–18% over the past ten years, and with further impacts from degradation the the species is suspected to be undergoing a moderately rapid population reduction. The majority of the loss has taken place within the lowlands, within the preferred elevational range of the species. Overall, the population is suspected to have undergone a rapid recent reduction approaching 30% over ten years, hence is assessed as Near Threatened. This reduction will continue unless there is a significant reduction in both the rate of habitat conversion within the range of the species, or until the majority of the population becomes restricted to more secure protected areas.
Population justification
The global population size has not been quantified but is believed to be large given the range and frequency of records in suitable habitat. It is a forest-dependent species and appears to occur only in primary or lightly logged forest (Peh et al. 2005). Within its range, the rate of forest conversion to plantations, primarily oil palm, has been very rapid over the past few decades (per Global Forest Watch 2022). There are recent records from remaining forested areas across the range, however the extent of suitable habitat is now considerably smaller than three generations ago. Where habitat is secure the species continues to be regularly observed (eBird 2022), though observing the species away from protected areas is becoming increasingly difficult. In Thailand, there are no post-2010 records, despite the species once occurring as far north as Krabi (eBird 2022). If the species does persist in Thailand, the population must now be very small. In Malaysia, there are post-2000 records from only Perak, Pahang and Johor, despite historical records from Kelantan, Terengganu, Selangor and Negeri Sembilan (MNS Bird Conservation Council 2021). Almost all records in Malaysia now come from protected areas or forest concessions, and the population is thought to be declining rapidly in lowland Indonesia, although here (especially in Kalimantan), there are large tracts of suitable habitat remaining. Forest loss is much lower in Brunei, where impacts on the species may be much less severe and much of the forest here is likely to be suitable for this species.
Trend justification
This species only occurs in good-quality forest (Peh et al. 2005, Eaton et al. 2021, eBird 2022). Consequently the population impact of forest cover loss is expected to be equal to or greater than the rate of loss. In the ten years to 2021, forest cover in this species' range was reduced by 15–18%, depending on the forest cover thresholds set (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). This value does not account for the impact of forest degradation, hence the population rate of reduction from habitat loss is likely to be greater than this. Similarly, since the species is most regularly encountered in low-lying forest (eBird 2022), where losses are greater, the overall rate of population reduction is suspected to be equivalent to c.15–29% over the last ten years. This rate is also precautionarily projected over the next ten years, although beyond that rates of loss may slow as the percentage area of forest outside protected areas diminishes.
Kenopia striata is restricted to the Sundaic lowlands, occurring in peninsular Thailand; Sabah, Sarawak and peninsular Malaysia; Kalimantan and Sumatra, Indonesia, and Brunei. It is now extirpated in Singapore (see Chasen 1923). Although widespread, it is generally uncommon throughout this range, occurring at low densities even in suitable habitats.
This species is found on the ground and in the lower storey of broadleaved evergreen forest, including lightly-logged areas, swamp forest and heath forest, up to 1,500 m (but usually below 650 m).
Forest destruction in the Sundaic lowlands of Indonesia and Malaysia has been extensive, for timber and conversion to agriculture. In particular the rapid expansion of oil palm has driven the conversion of the majority of remaining lowland forest in the region. Between 2011 and 2021, tree cover was reduced in its range by 15–18% (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). Most of this loss has occurred within the lowlands, where the highest densities of the species would be expected. Moreover, the impact of forest degradation will have added to rates of decline. Associated with the forest loss has been an increase in fire frequency, extent and severity, particularly during strong El Nino events (as in 1998). While the species can use secondary growth and higher elevations, the extent of the threats is such that this species' population is likely to be declining rapidly.
Conservation Actions Underway
None is known, however this species occurs in a number of protected areas throughout its range.
Conservation Actions Proposed
Determine population densities within different habitats and use these to assess the impacts of forest loss, differentiating where possible between primary and secondary forest types. Continue to protect significant areas of suitable forest at key sites, in both strictly protected areas and community-led multiple use areas.
Text account compilers
Berryman, A.
Contributors
Gilroy, J., Khwaja, N. & Benstead, P.
Recommended citation
BirdLife International (2024) Species factsheet: Striped Wren-babbler Kenopia striata. Downloaded from
https://datazone.birdlife.org/species/factsheet/striped-wren-babbler-kenopia-striata on 23/12/2024.
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 23/12/2024.