LC
Yunnan Nuthatch Sitta yunnanensis



Justification

Justification of Red List category
This species has a large range, hence it 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 has not been estimated but is unlikely to be very small 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
The population size of this species has not been quantified, but it is described as locally common and eBird (2023) indicate that it is often frequently encountered in relatively large numbers throughout its range. Given the area of forest within its range totals c.25,000 km2 (per Global Forest Watch 2023), it is unlikely to have a small population, even if only a small percentage of this is occupied.

Trend justification
The only identified threat to this species is habitat degradation and clearance, which has been minimal in the last ten years. Between 2011 and 2021, forest extent (>50% canopy cover) reduced by only c.2% (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein), and there is little indication that this rate will accelerate in the future. Menon et al. (2009) considered that the species might lose 40-50% of habitat to 2055 based on climate change impacts. However, this ecological niche modelling approach does not address uncertainties in the adaptability and plasticity of this species' ecology and it is treated with caution in the absence of monitoring data. In any instance, the overall rate of decline in this species is not thought to exceed 10% over ten years, and is suspected here to be declining at an ongoing rate of 1-9%.

Distribution and population

Historically thought to be endemic to China, where this species is recorded from south-east Tibet, southern Sichuan, much of Yunnan and westernmost Guizhou. It has also recently been discovered in Arunachal Pradesh (Bonpo and Kuriakose 2014), India, where it appears to be locally quite common (eBird 2023). Although it is not formally known from there, it almost certainly occurs in adjacent areas of Myanmar, given the lack of biogeographic barrier.

Ecology

This species occurs in open mature pine forest (avoiding other types of coniferous forest) with little undergrowth or scrub, mainly at 2,400-3,400 m. However, in summer (and more rarely winter), it can reach elevations of up to 4,000 m, while in winter it has (exceptionally) been noted as low as 1,200 m (Harrap 2020).

Threats

The majority of this species' habitat lies within rugged, inaccessible areas which appear to be free from threats. Nonetheless, very slow rates of habitat loss and degradation are precautionarily assumed to be impacting it. As a high-elevation species, it may be impacted by climate change. Menon et al. (2009) even suggested that 40-50% of its range could be lost by 2055 because of climate change impacts, however their methods relied on ecological niche modelling without any account for the potential adaptability of this species; more research is needed.

Conservation actions

Conservation Actions Underway
None is known, but the species does not occur in any large formally protected areas (UNEP-WCMC and IUCN 2022).

Conservation Actions Proposed
Conduct repeated surveys within the range to determine current distribution and abundance, as well as assess population trends in response to the apparent threat of climate change. Continue to monitor rates of forest cover loss using remote sensing data. Effectively protect significant areas of suitable forest at key sites.

Identification

12 cm. Small nuthatch with long, broad black mask and narrow white supercilium. Similar spp. Combination of size, supercilium, grey crown and uniform whitish underparts (including undertail-coverts), with only faint pale pinkish-buff wash, rule out other nuthatches in same range. Juveniles have narrower mask and shorter supercilium. Voice Calls include nasal kni, pi, tit and toik notes (former two often repeated) and harsh, scolding schri-schri-schri.., sometimes grading to strident, nasal ziew-ziew-ziew...

Acknowledgements

Text account compilers
Berryman, A.


Recommended citation
BirdLife International (2024) Species factsheet: Sitta yunnanensis. Downloaded from https://datazone.birdlife.org/species/factsheet/yunnan-nuthatch-sitta-yunnanensis on 21/02/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org on 21/02/2024.