Status of Wintering Populations of the Baikal Teal (Anas Formosa) In&Nbsp

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Journal of Asia-Paciﬁc Biodiversity 7 (2014) e213ee217

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Original article Status of wintering populations of the baikal teal (Anas formosa) in Geumgang River, Korea

Jae-Pyoung Yu a, Sung-Woo Han b, In-Hwan Paik a, Seon-Deok Jin a, Woon Kee Paek a,*

a National Science Museum, Daejeon, Republic of Korea b Geum Gang Migratory Bird Observatory, Gunsan, Jeollabuk-do, Republic of Korea

article info abstract

Article history: This study investigated the daily changes of individual numbers of the baikal teal migrating in Geumgang Received 19 March 2014 River from November in 2008 to March in 2009 and from November, 2011 to February, 2012. The finding Received in revised form from 2008 to 2009 showed that the highest number of 500,000 individuals (November, 2008) with an 27 March 2014 average of 146,582 123,705 individuals were recorded. The finding from 2011 to 2012 indicated that Accepted 1 April 2014 the highest number of 250,000 individuals (January, 2012) with an average of 61,696 63,407 in- Available online 24 April 2014 dividuals. The baikal teal’s population was increased in the early wintering period was not observed in the mid-wintering period when the Geumgang River became frozen. On the other hand, the population Keywords: Number of individuals tended to increase again in the late wintering period when the river began to thaw. As the baikal teals fl Freezing prefer at water areas without currents, they were mainly observed in the upper stream of Geumgang Geumgang estuary barrage estuary barrage but not in the downstream. Flat water Copyright Ó 2014, National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA). Production and hosting by ELSEVIER. All rights reserved.

Introduction individuals increased to 20,000w40,000 in 1986, the baikal teal had constantly wintered until the early 1990s (Yu and Hahm, 1994). The Baikal Teal (Anas formosa) is a common migratory bird Since the mid-1990s, however, the wintering groups had been wintering in Korea. More than about 95% of its total population decreased in Junam Reservoir. On the other hand, the wintering around the world winters (Won and Kim, 2012). Since the early groups increased in the reclaimed lands and reservoirs in the west 20th century, its number of individuals had been large enough to be coast, such as Cheonsuman Bay, Geumgang estuary, Donglim recorded as the most common duck in East Asia. In the mid-20th Reservoir, and Yeongamho Lake (Kang and Cho, 1996, 1998). century, however, the baikal teal was classified as an endangered Currently, at least 300,000w600,000 individuals of the baikal teal species because the number of this species drastically decreased winter (Ministry of Environment, 2004, 2005, 2006, 2007, 2008, due to reckless hunting and destruction of its habitats (Won and 2009, 2010, 2011, 2012, Won and Kim, 2012). Kim, 2012). The IUCN classified it as VU (Vulnerable) on the IUCN The population of the baikal teal wintering in Korea has been Red List. In 2011, however, it was classified as LC (Least Concern) as reported in ‘Simultaneous Census of Birds in Winter’ which has the number of individuals of the baikal teal has recently been been conducted annually between January and February by the increased (BirdLife International 2013). Ministry of Environment since 1999. In addition, several researches Based on the previous records in Gyeonggi-do areas, Austin on its wintering ecology and behaviors were also carried out (Kang (1948) believed this species as a passage migrant observed in Ko- and Cho, 1996, 1998). Most of the researches investigating the rea in spring and fall; however, in 1984, the large number of wintering populations of the baikal teal in Geumgang River have wintering groups of the baikal teal (5,000 individuals) were firstly been conducted once or twice a month during the wintering period observed at Junam Reservoir in winter. Since the number of its (Lee, 2000, Lee et al., 2001, Kim et al., 2004, Kang et al., 2010), Nevertheless, there has been no research investigating the daily changes of distribution status of the baikal teal during the * þ Corresponding author. Tel.: 82 42 601 7861. wintering period. E-mail address: [email protected] (W.K. Paek). Peer review under responsibility of National Science Museum of Korea (NSMK) and This study, therefore, investigated the changes of population of Korea National Arboretum (KNA). the baikal teal, aiming to provide the fundamental data to be used

http://dx.doi.org/10.1016/j.japb.2014.04.005 2287-884X/Copyright Ó 2014, National Science Museum of Korea (NSMK) and Korea National Arboretum (KNA). Production and hosting by ELSEVIER. All rights reserved. e214 JP Yu et al. / Journal of Asia-Pacific Biodiversity 7 (2014) e213ee217 for protecting and preserving the baikal teal representing Geum- Result and discussion gang estuary as a migratory bird sanctuary. The wintering status of the baikal teal (Anas formosa) in the Geumgang River Materials and methods The findings below present the daily changes of individual Study area numbers of the baikal teals migrating in Geumgangho Lake from November in 2008 to March in 2009 (excluding January in 2009) The Geumgang River originates in Subun-ri, Jangsu-eup, Jangsu- and from November in 2011 to February in 2012. The finding from gun, Jeollabuk-do. It flows in Daecheong Dam after passing through 2008 to 2009 showed that the highest number of 500,000 in- Okcheon-gun, Chungcheongbuk-do. Then, it flows in Jeollabuk-do dividuals (21 November, 2008) with an average of before meeting the Mihocheon stream again. Finally, it empties 146,582 123,705 individuals were recorded. The finding from into the west sea after flowing through Geumgang estuary barrage. 2011 to 2012 indicated that the highest number of 250,000 in- As the construction of the Geumgang estuary barrage was dividuals (31 January, 2012) with an average of 61,696 63,407 completed in 1990, the Geumgangho Lake was formed because the individuals. In the survey between 2011 and 2012, the highest inflow of river water and seawater to the estuary became blocked number of individuals was decreased by 50%, compared to that in off. Since it has small alluvial bars and reed beds, the Geumgangho the survey between 2008 and 2009. The average number of in- Lake is a popular migratory bird sanctuary in which waterbirds dividuals was also decreased by about 40%. Moreover, the number such as the baikal teals. Moreover, wide farmland areas formed of the baikal teals migrating to the Geumgang River during the early around the Geumgangho Lake are good feeding places for winter wintering period from November to December was decreased more migratory birds (Figure 1). drastically in 2011 than in 2008. After the end of January, however, the numbers of individuals in 2009 and 2012 showed similar re- Study methods sults around 60,000 (Table 1). When it comes to the changes of temperatures during the survey period, the average temperature in This study investigated the survey points and the individual November 2008 (8.79 C) was about 2.56 C lower than that in 2011 numbers of the baikal teal (Anas formosa) migrating in Geumgang (11.35 C). In December, on the other hand, the average temperature estuary on a daily basis from November in 2008 to March in 2009 (4 in 2008 was about 2.01 C higher than that in 2011. This result months; excluding January in 2009) and from November in 2011 to showed that the temperature difference in 2011 was relatively very February in 2012 (4 months). Point census method was used to large, compared to that in 2008. Additionally, the average tem- investigate the total number of individuals from the major survey peratures between January and March in 2012 were lower than points where the baikal teal was concentrated (Bibby et al., 1992), those in 2009. The overall temperature in average between Binoculars (10 25, Nikon) and telescopes (15w45, Nikon) were November and March in following year showed that the overall used to classify the species and to calculate the individual numbers. average between 2011 and 2012 (3.03 5.83 C) was about 1.29 C In addition, in order to investigate the current status of distri- lower than that between 2008 and 2009 (4.32 4.86 C) (Table 1). bution of the baikal teals wintering in Korea, this study analyzed The significant changes of temperature during the early wintering the data from ‘Simultaneous Census of Birds in Winter’ which has period in 2008 and 2011 might result from the fact that the changes been conducted annually in January or February for 14 years of surrounding environment, such as Saemangeum constructions, (1999w2012) by the Ministry of Environment. influenced the fluctuating numbers of wintering the baikal teals.

Figure 1. Map showing the survey points (C) and distribution areas (G) of the baikal teals at Geumgang River, Korea. JP Yu et al. / Journal of Asia-Paciﬁc Biodiversity 7 (2014) e213ee217 e215

Table 1 Monthly average number of individuals and temperature of the baikal teals at Geumgang River.

Years Items Nov. Dec. Jan. Feb. Mar. Overall average

NI Avg. 265,007 202,677 e 48,210 72,374 146,582 w 2008 2009 STD 120,277 93,578 e 67,917 51,864 123,705

T(C) Avg. 8.79 3.02 0.08 3.50 6.41 4.32 STD 3.93 4.21 3.43 3.30 4.12 4.86

NI Avg. 95,500 36,884 52,903 62,649 e 61,696 w 2011 2012 STD 28,748 40,787 89,413 63,515 e 63,407

T(C) Avg. 11.35 1.01 1.08 0.75 4.65 3.03 STD 4.81 3.54 2.84 3.78 2.68 5.83

NI.: number of individuals, T: temperature, Avg.: average, STD: standard deviation.

The population of the baikal teal migrating to Geumgang The status of the baikal teal (Anas formosa) wintering in Korea River tended to move northwards after wintering from November to March in the next year. The population of the According to the data from the ‘Simultaneous Census of Birds in baikal teal of which number increased in the early wintering Winter’ conducted by the Ministry of Environment, the baikal teal period was not observed in the mid-wintering period when has been observed more than once in 78 areas all over the country. Geumgang River became frozen (more than 50% frozen for about The number of individuals of the baikal teals wintering in Korea 27 days: 27 December, 2011w 17 January, 2012; 24w28 January, showed the highest number of 1,063,280 individuals in 2009 and 2012). On the other hand, the population tended to increase the lowest number of 185,838 individuals in 2001 with the annual again in the late wintering period when the river began to thaw average of 440,806 259,131.65 individuals (Figure 3). About (Figure 2). The baikal teals sleep or rest in flocks at safe reser- 200,000w450,000 individuals wintered from 1999 to 2006, voirs or swampy places during the daytime, whereas they begin whereas the number was rapidly increased over 800,000 in- to move at sunset and generally feed at nearby farmlands at dividuals in 2007. It has been increased up to about night (Won, 1981, Allport et al., 1990). As the river becomes 600,000w1,000,000 individuals until 2010, exceeding the annual frozen from the late December and January because of the average number of individuals. Since then, it tended to decrease decreased temperature, the Geumgang River is not an appro- again below the annual average until 2012 (Figure 3). priate place for the baikal teals to sleep and rest. In this sense, it Of the 78 areas where the baikal teal has been observed in Korea, is speculated that the baikal teals migrate to other places which Chungcheongnam-do has the most number of areas (22 areas), fol- are not frozen (Kang and Cho, 1996, Won and Kim, 2012). lowed by Jeollanam-do (18 areas) and Daegu and Gyeongsangbuk-do Moreover, the baikal teal is considered to prefer flat water areas (12 areas) (Table 2). Moreover, the baikal teals have been observed in without currents, in that it was mainly observed in the upper 52 areas (approximately 66% of the total) located in the west coast stream of Geumgang estuary barrage but not in the down- areas including Seoul and Gyeonggi-do, Chungcheongnam-do, stream. This might be because their energy consumption while Jeollabuk-do, and Jeollanam-do (Table 2). Regionally observed resting at flat water is less than at retarding basins. An number of individuals of the baikal teal showed that Jeollabuk-do increasing number of land reclamation projects concentrated including Geumgang River recorded the largest average number of around the west coast result in the increase of nearby farmlands individuals (256,385.6 individuals) and the highest number of and flat water such as artificial reservoirs and lakes. As a result, 740,005 individuals (recorded on 20 January, 2007), followed by this change can provide appropriate habitats to wintering ducks Jeollanam-do (163,327.8 individuals in average; the highest number including the baikal teals. Therefore, it is speculated that it can of 565,002 individuals, recorded on 23 January, 2010) and be one of the factors to the increasing number of wintering Chungcheongnam-do (18,336.5 individuals in average; the highest ducks including the baikal teals in the west coast areas (Kang number of 130,277 individuals, recorded on 13 January, 2009). 99% of and Cho, 1996, Lee, 2000, Choi et al., 2007). the total number of wintering the baikal teal individuals was mainly

Figure 3. Yearly changes in the number of individuals of the baikal teals in Korea (The Figure 2. Daily changes in the number of individuals of the baikal teals at Geumgang red line is the average value). (For interpretation of the references to color in this ﬁgure River. legend, the reader is referred to the web version of this article.) e216 JP Yu et al. / Journal of Asia-Paciﬁc Biodiversity 7 (2014) e213ee217

Table 2 The number of individuals of the baikal teals by each province.

Year SGG CN JB JN BGN DGB GW JJ Total

1999 150 485 11,940 200,000 505 213,080 2000 11,204 110,000 90,000 250 11 211,465 2001 2 3,598 178,412 100 3,529 197 185,838 2002 11,425 272,750 3,026 19 287,220 2003 9 303,144 2 303,155 2004 3,528 331,402 120,066 172 455,168 2005 5 8,720 90,411 238,103 201 148 337,588 2006 129 269,200 9 1,271 225 270,834 2007 70,864 740,005 8,400 57 819,326 2008 289 500,712 115,508 10,090 8 3 626,610 2009 30 130,277 400,097 525,734 7,133 5 1 1,063,277 2010 7 161 75,370 565,002 1,868 210 642,618 2011 582 2,955 431,976 498 161 10 1 436,183 2012 10 15,440 303,000 91 2 4 4 318,551 NA 5 22 7 18 10 12 3 1 78

NA: number of areas, SGG: Seoul and Gyeonggi-do, CN: Chungcheongnam-do, JB: Jeollabuk-do, JN: Jeollanam-do, BKN: Busan and Gyeongsangnam-do, DKB: Daegu & Gyeongsangbuk-do, GW: Gangwon-do, JJ:Jeju-do. concentrated in the west coast areas such as Jeollabuk-do, Jeolla- increased. Thus, it seems that the imbalance of taxonomic number nam-do, and Chungcheongnam-do (Table 2, Figure 4). of individuals will presumably be exacerbated. If wild birds Until the early 1990s, Junam Reservoir showed the highest including the baikal teals, which gather in large flocks, are number of 20,000w40,000 individuals (Yu and Hahm, 1994); concentrated in certain areas, they will be highly likely to be however, the number had been decreased since then. In Geumgang exposed to infectious diseases such as avian influenza (AI) and fowl estuary, the highest number of 300,000w450,000 individuals were cholera, which can lead to the mass mortality. Therefore, it is observed, which indicates that its wintering population has been suggested that measures to disperse the population of wild birds increasing (Kang et al., 2010). After the mid-1990s, the population should be prepared to make them not concentrated in certain areas. of the baikal teals started to increase along the west coast areas. Currently, more than 99% of its population is concentrated in the Acknowledgments west coast areas. This result implies that the areas which are suit- able for wintering ducks such as the baikal teals have been This study is supported and funded by National Science Museum increased because of the loss of mud flats but the increase of arti- of Korea, Gunsan City (The study on the changes of birds in ficial reservoirs and lakes, which result from an increasing number Geumgang River and Saemangeum areas), and the Ministry of of land reclamation projects concentrated around the west coast Science, ICT and Future Planning (NRF-2008-2004707). Many (Kang and Cho, 1996, Lee, 2000, Choi et al., 2007). The increase of thanks to the Gunsan branch of the Korean Association for Bird land reclamation projects results in the rapidly decreasing number Protection for the assistance and cooperation throughout the site of individuals of shorebirds as their habitats and feeding sources survey in this study. have been reduced by the loss of mud flats (Kang et al., 2011). On the other hand, the number of individuals of wintering ducks References receiving appropriate habitat environment has constantly Allport GA, Poole CM, Cho SR, Eldridge MI, Park EM. 1990. The feeding ecology, requirements and distribution of Baikal Teal Anas formosa in the Republic of Korea. Wildfowl 42:98e107. Austin OL. 1948. The birds of Korea. Bulletin of the Museum of Comparative Zoology at Harvard College 101:61. Bibby CJ, Burgess ND, Hill DA. 1992. Bird census technique. London: Academic press limited. 237 pp. BirdLife International. 2013. Anas formosa. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. Available at: www.iucnredlist.org/details/22680317/ 0 [Date accessed: 18 March 2014]. Choi YB, Kim IK, Jung SH, Yoo SH, Kang TH, Lee HS, Paek WK, Choi CG. 2007. A study on the use of wintering habitats of water birds arriving at Coastal Wetlands in Jeollanam Province, Korea. Korean Journal of Environment and Ecology 21 (3): 197e206. Kang HY, Cho SR. 1996. Wintering ecology of the Bilkal Teal Anas formosa and carrying capacity of their habitats. Korean Journal of Ornithology 3 (1):33e41. Kang HY, Cho SR. 1998. Study on wintering behavioral patterns of Baikal Teal Anas formosa at Nonsan and Kum-gang Lake, Korea. Korean Journal of Ornithology 5 (1):57e62. Kang TH, Kim SH, Han SW, Lee SW, Paek WK. 2010. A study on the community characteristics and habitat use of wintering waterbirds in Geumgang River, Korea. Korean Journal of Ornithology 17 (1):1e10. Kang TH, Yoo SH, Yu JP, Lee HS, Kim IK. 2011. A study on the community of wintering waterbirds in Seamangeum. Korean Journal of Environment and Ecology 25 (1):81e90. Kim JH, Park JY, Yi JY, Yoo BH, Lee MH. 2004. The migration route and monitoring on the migratory birds in Korea. Incheon: National Institute of Environmental Research. 138 pp. Lee KS. 2000. Current status and population fluctuations of waterbirds on the west Figure 4. Yearly changes in the number of individuals of the baikal teals by each coast of Korea. Ph. D. thesis. Seoul: University of Kyunghee. 211 pp. province (SGG: Seoul and Gyeonggi-do, CN: Chungcheongnam-do, JB: Jeollabuk-do, JN: Lee WS, Park CR, Rhim SJ, Hur WH. 2001. Characteristics, protection and manage- Jeollanam-do, BKN: Busan & Gyeongsangnam-do, DKB: Daegu & Gyeongsangbuk-do, ment of bird community in Geumgang River Estuary. Korean Journal of Ecology GW: Gangwon-do, JJ:Jeju-do). 24 (3):181e189. JP Yu et al. / Journal of Asia-Pacific Biodiversity 7 (2014) e213ee217 e217

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