116 The status of Ferruginous Duck Aythya nyroca breeding and wintering in China ZHAO XUMAO1,2 & ROLLER MAMING1* 1Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, Xinjiang 830011, P.R. China. 2University of Chinese Academy of Sciences, Beijing 100049, P.R. China. *Correspondence author. E-mail: [email protected] Abstract Analysis of data published in the China Bird Report (CBR) and other literature between 1979 and 2013, along with our own field observations, found that the Ferruginous Duck Aythya nyroca now occurs throughout most of China. This contrasts with the situation in 1979, when the species was restricted to a few areas in the west of the country. Ferruginous Duck is predominately a winter visitor to China; up to 850 birds have been counted in Yunnan Province, 4,000 in Sichuan Province, and the wintering population is estimated at 6,000–8,000 individuals. In summer, the breeding population is estimated at 3,000–4,000 individuals (1,500–2,000 pairs), with highest concentrations in Xinjiang (c. 900–1,700 individuals) and Inner Mongolia (750–1,400 individuals). In China, females lay 6–11 eggs, which hatch in early June. The present population in China is likely to have spread from neighbouring central Asia (Kazakhstan, Kyrgyzstan or Mongolia). Since 1980, the climate had gradually changed from warm-dry conditions to a wetter climate in northwest China, making it a more suitable breeding area for this species and providing corridors for their expansion to the east. If the present trend continues, southern China could in the near future become an important wintering area for a duck species that is now increasingly common elsewhere in China. Key words: Aythya nyroca, breeding, distribution, Ferruginous Duck, habitat, population size, range expansion, Xinjiang. The Ferruginous Duck Aythya nyroca AEWA) (BirdLife International 2012). is listed as “Near Threatened” on the There have been international concerns IUCN Red List and is also a priority about population declines and range species on three prominent international contraction in the western Palearctic, and an conservation treaties: the European Union international species action plan has been Birds Directive, the Bern Convention and developed to help to conserve the species the Bonn Convention (under the African- (Robinson & Hughes 2006). Eurasian Migratory Waterbird Agreement; The Ferruginous Duck breeds principally ©Wildfowl & Wetlands Trust Wildfowl (2014) 64: 116–125 Ferruginous Duck in China 117 in southwest Asia (from the west to China perhaps into the tens of thousands, in Asia and the south to Pakistan and India), central (Li et al. 2009). In China, it was known to be and eastern Europe, and North Africa a summer visitor to the northwest and a (Callaghan 1999; Vinicombe 2000; Kear migrant through the central provinces, with 2005). Four populations are currently winter records from the middle reaches of recognised by Wetlands International and the Yangtze floodplain reported during the one encompassing China is described as the mid–late 20th century (Cheng 1987). More “S, E and SE Asia” population. The recently, Ferruginous Duck accounted for c. wintering range of the East European 0.13% of all wildfowl recorded as taken by population partly overlaps with the breeding hunters between 2009–2012 (MaMing et al. range and extends to the Middle East, 2012), though recent photos of ducks northeast and west Africa (mainly Mali and recovered from hunters suggest that this Nigeria) and southeast Asia (Kear 2005). proportion could be higher at around 5–10% Currently the global population is estimated (Fig. 1). There is much suitable habitat in the at c. 177,400–252,600 individuals (Wetlands country, and this species is now thought to be International 2014). The duck has undergone common in China, although quantitative data declines in its population size and changes in are lacking. This study is the first review of distribution over the past few decades (Ali & the available data to assess the population, Ripley 1978; Perennou et al. 1994; Lopez distribution and breeding ecology of this & Mundkur 1997; Grimmett et al. 1999). species in China. Primary reasons for its decline are thought to be unsustainable levels of hunting, habitat Methods degradation and loss (Callaghan 1997). In order to assess breeding and wintering Recent surveys have found high numbers, abundance and distribution, and to describe Figure 1. Eighty six Ferruginous Duck in c. 580 wild duck seized from poachers by the Xinjiang police on 9th July 2014. (Photograph by Roller MaMing). ©Wildfowl & Wetlands Trust Wildfowl (2014) 64: 116–125 118 Ferruginous Duck in China the breeding ecology of the Ferruginous The distribution of sites where Duck in China, we reviewed about ten years Ferruginous Duck have been recorded in of data published in the China Bird Report China since 1979 is shown in Fig. 2. (CBR, checking c. 438 reports from across Information on the location of each site was the country) along with reference literature derived from the site forms submitted by from 1979 to 2013, including international observers. Although it was not feasible to waterbird census (IWC) data collated by check the accuracy of all information Wetlands International and previously by recorded, an attempt was made to check the International Waterfowl & Wetlands the location of all sites known to be Research Bureau and the Asian Wetland important for the species. Some sites where Bureau (Cheng 1979; Lopez & Mundkur only local names were recorded and 1997; Delany & Scott 2002; National numbers were relatively low could not be Forestry Bureau, NFB 2009; Li et al. 2009; located precisely; sites illustrated in Fig. 2 Ma 2011; Zhao et al. 2013). CBR data are therefore account for only c. 60% of all collected by volunteers who differ in levels records of Ferruginous Duck sites from the of skill in identifying species and making review. counts; therefore it is likely that, although Ferruginous Duck are relatively easy to Results identify in the field, there are some errors in Population size the data, and an increased interest in ornithology within China has biased towards From published winter count data (Rose & increased reporting rates in more recent Scott 1994; China Bird Report 2001–2013; years. In collating records, we have attempted Delany & Scott 2002; National Forestry to verify the data received from coordinators Bureau, NFB 2009; Li et al. 2009; Ma 2011) and observers, and have checked with we estimated that there is a non-breeding coordinators the validity of some of the population of 6,000–8,000 Ferruginous information. No information has been Duck in China (Table 1). In general, provided to the China Bird Report for Hong the species occurs at elevations ranging Kong and Taiwan, so literature searches and from 0–3,900 m above sea level, but is information from key researchers provided mostly found at 600–1,500 m. Maximum the best overview of the status of numbers occurred in January (about Ferruginous Duck in these two regions. 6,000 individuals), although significant In addition, from 2011–2013 inclusive, numbers (between 3,300–5,400) are also we carried out field surveys of the breeding reported in February, November and ecology, number of breeding pairs and December, with smaller numbers (380– migration of Ferruginous Duck in the 1,700) in March–October (Fig. 3). From Xinjiang Uygur Autonomous Region of these data it appears that Ferruginous Duck China, using fixed route surveys, direct is mainly a wintering species in southern counts and interview surveys (Zhao et al. China, where it occurs from early October 2013). to March. ©Wildfowl & Wetlands Trust Wildfowl (2014) 64: 116–125 Ferruginous Duck in China 119 Figure 2. Distribution of Ferruginous Duck in China from 1979 to 2013. Note: ○ = wintering concentrations (recorded in the last ten years); ● = summer concentrations (recorded in the last ten years); ▲ = historical records (pre-1979); ↓ = migration route; ? = vagrant. The species also breeds in northern and Xinjiang, at Wuliangsuhai Lake in Inner northwest China. In spring (early March to Mongolia, and in southern Tibet. During late April) the species migrates to northern migration, it was found at a few places such China and only small numbers remain in the as Gansu, southern Shaanxi, northern wintering areas to which they return Sichuan, Yunnan and southwest Guangxi. In between late October and mid-November. winter it was occasionally reported from Shandong and Hunan provinces and less Distribution frequently elsewhere (Cheng 1979). More The range of this species appears to have recently, the ornithological literature and the changed considerably over the last 40 years, CBR indicate that ducks have extended their although the extent to which it has done so range to most of China, and the species has is difficult to ascertain, as observer coverage been recorded in c. 94% of all provinces and reporting has increased with the recent over the past decade, including Xinjiang, development of the CBR and bird-watching Tibet, Qinghai, Gansu, Inner Mongolia, societies in China. In the 1970s, the species Liaoning, Hebei, Beijing, Tianjin, Ningxia, bred principally in northern and western Shanxi, Shaanxi, Shandong, Jiangsu, Anhui, ©Wildfowl & Wetlands Trust Wildfowl (2014) 64: 116–125 120 inChina Ferruginous Duck ©Wildfowl Trust &Wetlands Table 1. Maximum numbers of Ferruginous Duck recorded in various parts of China in a single year between 1979 and 2012, broken down by season.