East Asian buntings: Ongoing illegal trade and encouraging conservation responses

The dramatic decline in the once superabundant Yellow‐breasted Bunting Emberiza aureola, a widely distributed Eurasian songbird, triggered worldwide media interest. Five years after the initial publication, we set out to give an update on the status of this critically endangered species, the conservation actions that followed, and the lessons that can be learned from this exceptional case for the conservation of migratory land birds in Asia and beyond. While there are signs of possible population recovery in the Yellow‐breasted Bunting, other migratory songbird species were recently observed to be trapped in huge numbers, which could lead to further declines. We argue that the Yellow‐breasted Bunting can be used as a flagship species to promote the conservation of East Asian land bird migrants.


| INTRODUCTION
The Yellow-breasted Bunting (Emberiza aureola) was once one of the most abundant songbirds of the Palearctic, but declined by 84.3-94.7% between 1980 and 2013, accompanied by a range contraction of 5,000 km (Kamp et al., 2015). The decline was attributed to illegal, widespread, and large-scale hunting in China for human consumption. The rapid decline of such a common species over huge areas was considered unprecedented in human memory, with exception of the well-known fate of the Passenger Pigeon (Ectopistes migratorius) of North America (Bucher, 1992). The publication of the precipitous decline triggered considerable media interest that led to immediate conservation responses on the ground. Five years after the initial publication in Conservation Biology, we here provide an update on the status and conservation of this muchdepleted species, examine the status of related, persecutionprone bunting species, and identify priorities for research on and the conservation of East Asian land birds.

| ONGOING TRAPPING AND TRADE
Since the publication of the magnitude of the decline and its potential main driver (Kamp et al., 2015), information on further incidents of illegal trapping in China surfaced, suggesting ongoing illegal persecution (summarized in Table 1, Figure 1). The trade still seems to be an industrialscale business: Commercial facilities buy Yellow-breasted Buntings from local fowlers, fatten them up with chemical fattening agents, and sell them to buyers from restaurants in South China (Tencent QQ News, 2016).

| CONSERVATION RESPONSE AND LAW ENFORCEMENT
The initial report on the extreme decline resulted in an encouraging response by conservationists, who lobbied for a higher legal protection status (Heredja, 2016 Wang & Ziyi, 2018). Law enforcement has much improved, the police follows up reports of illegal trapping immediately, and poachers caught red-handed are arrested and fined (APWCPP, 2018;Townshend, 2018). Online trade was restricted soon after bunting sales were discovered on China's largest online sales platform, Taobao (Townshend, 2017). Local farm managers have begun to improve stopover habitat for the species (Hong Kong Birdwatching Society, 2017). More recently, China has significantly restricted wildlife trade in the course of the SARS-CoV-2 pandemic, which might further decrease the persecution pressure on Yellow-breasted Buntings (Mallapaty, 2020).

| ONGOING DECLINES BUT POTENTIAL RECENT, LOCAL POPULATION RECOVERY
Additional data were publicized in response to Kamp et al. (2015), describing exclusively declines and local extinctions until 2013, for example, from breeding sites in Central Siberia (Bourski, 2015), from Lake Baikal (Mlikovsky & Styblo, 2016), the Russian Far East (Antonov, 2016) and Hokkaido/Japan (Tamada, Hayama, Umeki, Takada, & Tomizawa, 2017). Declining numbers were also reported from stop-over sites in southern Primorye, Russian Far East (Valchuk et al., 2017) and Korea (Choi, Nam, Kim, Park, & Park, 2020). Interestingly, from ca. 2016 onwards, several sites in Russia were recolonized, and a number of small populations recovered considerably. In European Russia, the species was reported from 20 sites between 2014 and 2018 (Mischenko, 2019), including in an area where it was believed extinct by around 2000 (Kamp et al., 2015). Larger numbers were found around Lake Baikal (Dorzhiev, Badmaeva, & Gulgenov, 2018;Ivushkin, 2017;Popov, 2017) and on Kamchatka (Gerasimov & Lobkov, 2019). It is unclear if these increases indicate a genuine recovery, or mirror an increased observer effort, given the high attention the species currently receives. The fact that abandoned sites were recolonized might at least point to a beginning recovery in some areas, notably in European Russia (Mischenko, 2019).

| EAST ASIAN SONGBIRDS UNDER PRESSURE: PRIORITIES FOR RESEARCH AND CONSERVATION
Legal and illegal trapping for food in China and adjacent countries is not restricted to Yellow-breasted Buntings, but affects a whole range of species (Li & Wilcove, 2005). However, in many reports of songbird confiscations, migratory buntings make up the bulk of the birds. This is most likely because they roost communally and can, therefore, be trapped in large numbers. Furthermore, because they are long-distance migrants, they are physiologically able to gain weight quickly, and are therefore breeding migration winter F I G U R E 1 Sites where Yellow-breasted Buntings were traded or confiscated (red dots) or found trapped in mist-nets (red crosses) between 2014 and 2020. Data from Kamp et al. (2015) are plotted for comparison (orange dots). The size of the symbol represents the number of individuals (range: 1-500,000 for dots, 1-100 for crosses). Dashed lines connect a site in Russia where geolocators were fitted to breeding Yellow-breasted Buntings and approximate autumn stopover and wintering positions of these birds (from Heim et al., 2020). The breeding range of the species is marked yellow, the wintering range blue (after BirdLife International, 2020) possible to be fattened-up before selling. With the depletion of Yellow-breasted Bunting stocks, poachers might have already shifted to other, still more abundant species. Photographs and videos from police raids show larger quantities of Chestnut Bunting (Emberiza rutila) and Tristram's Bunting (Emberiza tristrami) (Tencent QQ News, 2016;Weibo News, 2019). Little Buntings (Emberiza pusilla) have been shown to be sold as "rice birds" (a name previously employed only for Yellowbreasted Buntings) in Chinese restaurants by the means of genetic analyses (C. Dingle, pers. comm.). Consumption might therefore also partly explain local declines in further migratory Emberiza species (Choi et al., 2020;Edenius et al., 2017;Valchuk et al., 2017;Yakovleva & Sukhov, 2017). Declines on the East Asian flyway are not limited to buntings, but are shown by a larger number of land birds (Tamada et al., 2017;Tamada, Tomizawa, Umeki, & Takada, 2014). The flyway exhibits the largest number of threatened migratory species, but is also the least studied one globally (Yong et al., 2015). Little is known about further threats that drive declines except persecution. Asia has experienced dramatic land transformations with currently more than 50% of the land area under agriculture (Chen & Han, 2015). Southeast Asia, the main wintering area for Asian land birds, has the highest deforestation rate of any tropical region (Hansen et al., 2013). Forest loss has been suggested as a main driver of decline in migratory bird populations on Hainan (Xu et al., 2017) and in Japan (Yamaura et al., 2009). Pesticide use, which has doubled in East Asia between 1990 and 2010 (FAO, 2019), may affect bird populations indirectly through reduced food availability or directly through poisoning (e.g., Eng, Stutchbury, & Morrissey, 2017). Rice systems, home to many buntings in winter, have been intensified strongly, with accelerated crop rotation and strongly reduced periods of food availability for granivorous birds (Amira, Rinalfi, & Azhar, 2018;Dawe, Pandey, & Nelson, 2010). On top of that, climate change affects bird populations globally, including several endangered East Asian species (Wu & Shi, 2016).
In the light of these multiple threats to songbirds in East Asia, we suggest a number of research and conservation priorities: 1. Continue to develop the Land Bird Monitoring Scheme for Northeast Asia (Wee, 2015) 2. Harness existing data (e.g., eBird) to establish population trends for the region 3. Establish the scale, species involved and geographical patterns of land bird persecution, trade and consumption in East Asia 4. Relate spatial and temporal data on bird occurrences to flyway-wide data on changes in land cover, landuse intensity and climate to identify the main drivers of population declines The Yellow-breasted Bunting might serve as a flagship species (sensu Caro & O'Doherty, 1999) in attempts to intensify the conservation of migratory land birds in East Asia as this appealing and vocal species is now well known in many countries along the flyway and has raised the awareness of a global audience due to its strong decline.

ACKNOWLEDGMENT
Open access funding enabled and organized by Projekt DEAL.