The Sichuan basin of central China is a fertile, densely populated region c.500 m above sea-level, and high mountains rise abruptly to several thousand metres (maximum 7,556 m at Gongga Shan) to the west of the basin and to over 3,000 m to the north of it. The mountains adjacent to the basin receive high rainfall and support rich forests. There are distinct subtropical, temperate, subalpine and alpine zones, similar to those on the south-facing Himalayas. This EBA comprises the forest areas of the temperate zone, and is represented on the map by all land between 1,500 and 3,650 m within the known distributions of the restricted-range birds. It spans several provinces: central and northern Sichuan, north-west Guizhou, extreme north-east Yunnan, southern Gansu, southern Shaanxi and extreme western Hubei (and possibly extreme western Henan).

In the high mountains to the west of the basin there is geographical overlap between this EBA and the West Sichuan mountains (EBA 138), but the birds of that EBA occur at higher altitudes in the subalpine zone. South-west of the basin, in the southern part of the Central Sichuan mountains, there is geographical overlap with the Chinese subtropical forests (EBA 140), but the birds of that EBA mainly occur at lower altitudes in the subtropical zone. The present EBA is also adjacent to the Qinghai mountains (EBA 135) and Yunnan mountains (EBA 139), but probably does not overlap geographically with either.

The restricted-range species-which include the monotypic endemic genus Latoucheornis-breed in coniferous, broadleaf and mixed broadleaf-coniferous forest in the temperate zone, mainly at c.1,800-3,650 m, and tend to be associated with areas having an understorey of bamboo or deciduous scrub. Garrulax lunulatus ranges down to 1,500 m, and Aegithalos fuliginosus down to 1,000 m, although there is some evidence that A. fuliginosus moves to these lower altitudes only outside the breeding season (Harrap and Quinn 1996). Garrulax formosus appears to breed mainly in the temperate zone and descend to subtropical forests only outside the breeding season, when it overlaps in range and habitat requirements with the birds of EBA 140.

Several restricted-range species occur widely within the EBA, but some others seem far more localized, although much undoubtedly remains to be learned about their distributions in this poorly known region. Paradoxornis przewalskii and Garrulax sukatschewi are only known from the Min Shan, and Luscinia obscura and L. ruficeps are both recorded from just a handful of breeding localities in the northern half of the EBA. Paradoxornis zappeyi is confined to the southern part of the EBA.

The main threat to this EBA is forest loss. Forest cover has declined rapidly in Sichuan since the late 1960s, because timber quotas have consistently been set above sustainable levels, and forest has been cleared for cultivation and pasture. The province's forest cover is estimated to have declined from 19% to 12.6% between the early 1950s and 1988, mature natural forest being particularly affected (Smil 1984, 1993). Five of the restricted-range bird species are listed as threatened because they have particularly small ranges, and are therefore most likely to be vulnerable to this loss of habitat. A more widespread threatened species which occurs in the EBA is Wood Snipe Gallinago nemoricola (classified as Vulnerable). The only known wild population of Crested Ibis Nipponia nippon (listed as Critical), a species which formerly ranged widely in eastern Asia, is in the foothills of the Qinling Shan.

The location and extent of this EBA closely matches the current distribution of giant panda Ailuropoda melanoleuca (MacKinnon et al. 1989), for, like the restricted-range birds, this mammal occurs in temperate-zone forests with a bamboo understorey. The 13 reserves which have been established for giant panda, and for other large mammals such as takin Budorcas taxicolor and golden monkey Rhinopithecus roxellanae, contain large areas of habitat suitable for the restricted-range birds of this EBA, although their distribution and abundance within these protected areas is poorly known. Omei Shan is protected by its status as one of China's five sacred mountains (Robson 1989), although development for tourism there is causing some localized forest loss (M. J. Crosby pers. obs. 1991).

Recommended citation
BirdLife International (2024) Endemic Bird Area factsheet: Central Sichuan mountains. Downloaded from https://datazone.birdlife.org/eba/factsheet/132 on 22/11/2024.