• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Justification of Red List category
This range-restricted bunting was formerly assessed as Vulnerable, however the most recent information indicates that the species does not meet or approach the thresholds for listing as threatened. While a significant population reduction was suspected to have taken place during the 20th century, both occupancy information from national atlases and indirect evidence from banding studies of migrants indicate the population is likely stable or increasing. The previous population estimate is considered to have been too low and the population is considered very likely to currently exceed 10,000 mature individuals. There remains the potential threat from indiscriminate trapping of small birds for food and for the cage bird trade, however there is no evidence that these have affected this species in recent decades, in contrast to some congeners with partly overlapping ranges. 

Population justification
The global population had previously been roughly estimated to be in the band c.2,500-9,999 mature individuals (BirdLife International 2001). This appears to have been a considerable underestimate of the true population size, with Brazil (2009) considering that there were c. 100,000 breeding pairs. Without more certain information, the current population size is uncertain. The observation that at the northern edge of the range the species breeds down to near sea level may also indicate that the overall population size was likely to be considerably higher than previously suspected (Kaneko 2020). Densities had not significantly changed in 40 years at locations where habitat associations were studied: in 1977 densities were 30 individuals per km² while in 2014 densities were 50 individuals per km² (Deguchi et al. 2017). These high densities strongly indicates that the population size is not as small as previously suggested, and it is very likely to exceed thresholds for listing as threatened.
In the previous century the population is thought to have been greatly reduced from historical high abundance (Brazil 1991), however there was a small increase in breeding squares detected between the 1974-78 and the 1997-2004 Japanese Bird Atlas (Ministry of the Environment Biodiversity Center of Japan 2004), which has continued in the 2016-2021 atlas (Breeding Bird Distribution Survey 2021). Despite fears that the species may be impacted in a similar way to other migratory bunting species along the East Asian flyway, there is no evidence of a reduction in the numbers recorded during migration through Korea (Choi et al. 2020). Numbers of this species banded increased between the two periods investigated (1950s-1980s and 1990s-2010s), although numbers involved were small (Choi et al. 2020).

Trend justification
The species was reported to have suffered a dramatic reduction in abundance during the 20th century (Brazil 1991). Pesticide use appears to be correlated with this decline, though habitat degradation and loss to agriculture more generally are considered to have been the main drivers, potentially with an additional impact from bird trapping (Copete 2020).
An indirect study of comparative abundance trends in buntings in Korea (Choi et al. 2020) found more individuals had been banded in the 1990s-2010s versus the 1950s-1980s, and the Japan bird atlas indicates an increase in the number of confirmed or likely breeding grid squares from 89 in 1974-1978 to 126 in 2016-2021 (Breeding Bird Distribution Survey Committee 2021). As such the population is assessed as stable or possibly increasing.

Emberiza sulphurata breeds in northern Honshu, Japan, between April and August before individuals migrate either through North Korea and South Korea [including records from Marado island (Kim et al. 2014)] and coastal mainland China, or along the chain of islands southwest from Honshu through Shikoku and Kyushu, to winter in Taiwan, China (eBird 2021, GBIF.org 2021) and south to Luzon (Philippines) (with most records from Ilocos Norte in the far northwest [D. Allen in litt. 2012]).
There are several mid-winter records from the southern coast of mainland China (Fujian, Guangdong) and Hong Kong (China), and at least formerly some individuals remained in southern Japan or wintered in the Ryukyu Islands (Copete 2020).
It has been described as generally uncommon in its restricted breeding range in Japan, and is believed to have declined significantly during the 20th century. In the past half century, the population and breeding distribution appears to have initially stabilised (Ministry of the Environment Biodiversity Center of Japan 2004) and subsequently increased (Breeding Bird Distribution Survey Committee 2021).

It breeds from near sea level in the north of the range to 1,500 m (Kaneko 2020) but typically from c. 600 m to 1,500 m, in deciduous and mixed forests, on wooded slopes and in high valleys, around woodland edges and in park-like areas with shrubs and thickets. It nests in bushes or on the ground. Paddyfield abandonment was found to have no effect on the species, although may provide additional marginal habitat (Deguchi et al. 2017). On migration, it occurs in shrubby clearings in open woodland, in low secondary growth and open cultivated land with bushes and thickets, and sometimes in open grasslands. In its wintering range, it is found in grasslands, scrub, pine forest and cultivated areas, up to 1,500 m. 

Historic declines have been attributed to trapping for the cage bird trade in passage areas in southern China and degradation and loss of habitat to agricultural intensification, especially in wintering areas (Copete 2020). The reduction in abundance during the last century is thought to have correlated with pesticide use, though there is no direct evidence for this impact (Copete 2020). Recent increases suggest that these threats are no longer sufficient to be causing declines.

Conservation Actions Underway
It is legally protected in Japan, North Korea and Hong Kong. It occurs in some National Wildlife Protection Areas in central Honshu, Japan, including Asama (Gunma and Nagano prefectures), the North Alps (Toyama, Nagano and Gifu prefectures) and Katano Duck Pond (Ishikawa prefecture). Some of its breeding and staging grounds are also protected as prefecture protection areas, such as Nikko (Tochigi prefecture), Myoko-san (Niigata prefecture), Nojiri-ko (Nagano prefecture), Matsunaga-wan (Hiroshima prefecture) and Kakara-jima (Saga prefecture).

Conservation Actions Proposed
Research the status of its breeding population and carry out surveys to establish its main wintering area. Coordinate a study of the decline and conservation requirements of migratory passerines in Asia. Study its habitat requirements during winter and make land management recommendations (D. Allen in litt. 2012). Assess the level of threat posed by nocturnal trapping during migration (D. Allen in litt. 2012). Ensure it is legally protected across its entire range.

14 cm. Olive-green and yellow bunting. Black lores. Greenish-yellow crown, sides of head and hindneck. Olive-green mantle streaked with black. Olive-grey lower back, rump and uppertail-coverts. Lemon-yellow underparts becoming paler on belly and green and streaked on flanks. White tips to median and greater coverts form double wing-bar.

Text account compilers
Martin, R.

Contributors
Allen, D., Benstead, P., Brusland, S., Everest, J., Gilroy, J., North, A. & Taylor, J.

---

Recommended citation
BirdLife International (2024) Species factsheet: Yellow Bunting Emberiza sulphurata. Downloaded from https://datazone.birdlife.org/species/factsheet/yellow-bunting-emberiza-sulphurata 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.