LC
Swinhoe's Rail Coturnicops exquisitus



Justification

Justification of Red List category
This species has a large range, and hence does not approach the thresholds for Vulnerable under 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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is not known, and hence does not approach the thresholds for Vulnerable under 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 the species is evaluated as Least Concern.

Population justification
Previously, this species was thought to be very rare, with some sources (e.g. Brazil 2009) suggesting that the population probably numbered only hundreds of pairs. However, confirmation of the species' vocalisations (see Wulf et al. 2017) has allowed surveys to determine that it is likely much more numerous. Published densities suggest the species is locally common, with values of 3-5 birds/km2 recorded in Russia (Antonov and Parilov 2009) and, in Japan, up to 15 birds have been heard vocalising at a single wetland site only 1 km2 in size (Senzaki et al. 2021). Applying these values to form a population estimate is difficult due to uncertainties with the breeding range and the extent of suitable habitat. Historically, the species was mapped as breeding in two highly disjunct regions in Transbaikalia (Russia) and the Primorye area, especially near Khanka Lake, in the very south-east of Russia, however there are recent records from intervening areas (Heim et al. 2018, eBird 2022) as well as northern Japan (Senzaki et al. 2021) suggesting a much broader distribution than previously supposed. In the absence of data from which to derive an estimate of suitable habitat extent, the population size is therefore considered unknown, although it is suspected that it is not very small.

Trend justification
There are no data available to calculate a rate of population reduction in this species, although it is not thought to be declining especially rapidly. Nonetheless, slow declines are suspected because of ongoing conversion of wetland habitats across its range (BirdLife International 2001, Senzaki et al. 2021).

Distribution and population

Formerly known from only a handful of sites (BirdLife International 2001) but now known to be more widespread. Recently confirmed on the shores of Lake Baikal (see Anisimova et al. 2019) and likely occurs east near contiguously through south-east Russia and north-east China. In Mongolia, at least a passage migrant, although perhaps breeds (Ganbold et al. 2017, eBird 2022), and recently the species has been confirmed in the breeding season in at least three wetlands in northern Japan (Miya et al. 2005, Senzaki et al. 2021). When not vocalising, it is highly elusive hence its non-breeding grounds are inadequately known. It has been recorded on passage and in winter in Mongolia, North Korea, South Korea, Japan (including the Nansei Shoto Islands) and southern and eastern China.

Ecology

Recorded in wet, grassy meadows and tussock-swamps in the lowlands, reed-swamps, grassy swamps near rivers, rice-fields and around streams and pools with thick cover. At one breeding site in Russia, all observations were made in "wet, low-growing sedge meadows with rich litter" and the species was entirely absent from wetland areas that had been burnt in the spring of the survey year (Heim et al. 2019).

Threats

The main population stress is thought to be from the destruction and modification of wetlands in both its breeding and wintering ranges owing to a number of threatening processes. Habitat in south-eastern Russia is being reduced as a result of drainage and ploughing for conversion of wetlands to agriculture. In China, the Zhalong National Nature Reserve is threatened by agricultural encroachment, reed-harvesting, hunting and water extraction for agriculture. The Poyang Hu Nature Reserve is threatened by vegetation cutting and reclamation for agriculture. The over-use of pesticides may affect it. Ultimately, however, the extent to which these threats are driving declines in C. exquisitus is largely unknown.

Conservation actions

Conservation Actions Underway
It is legally protected in China, South Korea and Japan. It occurs in a number of protected areas including Khanakiski (Khanka) and Khinganski State Reserves (Russia), Mongol Daguur Nature Reserve (single record) (Mongolia), and Xingkai Hu (Lake Khanka), Zhalong National Nature Reserve and Poyang Hu Nature Reserve (China). No specific actions for this species are known.

Conservation Actions Proposed
Refine population estimates. Elucidate the extent of its breeding range using playback experiments. Research its ecological requirements and identify key threats. Improve protection of its habitat in Russia and in protected areas in China, as well as on the wintering grounds.

Identification

13 cm. Tiny, compact, buffish rail. Blackish top of head and upperparts. Conspicuous cinnamon stripes and thin white bars from mantle to tail. Greyish-brown face. White underparts with tawny-ochre barring on foreneck, upper breast, flanks and undertail-coverts. White secondaries. Similar spp. White secondaries and white barring on upperparts separate it from all sympatric rails.

Acknowledgements

Text account compilers
Berryman, A.

Contributors
Chan, S., He, F., Heim, W., North, A., Benstead, P., Peet, N., Crosby, M., Taylor, J., Martin, R. & Bird, J.


Recommended citation
BirdLife International (2024) Species factsheet: Swinhoe's Rail Coturnicops exquisitus. Downloaded from https://datazone.birdlife.org/species/factsheet/swinhoes-rail-coturnicops-exquisitus 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.