Ornithol Sci 13: 67 – 75 (2014)

ORIGINAL ARTICLE Satellite tracking of migrating Whooper Swans Cygnus cygnus wintering in .

Tetsuo SHIMADA1,#, Noriyuki M. YAMAGUCHI2,*, Naoya HIJIKATA2,**, Emiko HIRAOKA2, Jerry W. HUPP3, Paul L. FLINT3, Ken-ichi TOKITA4,***, Go FUJITA2, Kiyoshi UCHIDA5, Fumio SATO6, Masayuki KURECHI7, John M. PEARCE3, Andrew M. RAMEY3 and Hiroyoshi HIGUCHI2,**

1 The Miyagi Prefectural Izunuma-Uchinuma Environmental Foundation, 17–2 Shikimi, Wakayanagi, Kurihara- shi, Miyagi 989–5504, Japan 2 Laboratory of Biodiversity Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1–1–1, Bunkyo-ku, Tokyo 113–8657, Japan 3 U.S. Geological Survey, Alaska Science Center, 4210 University Drive, Anchorage, AK 99508, USA 4 Abiko City Museum of Birds, 234–3 Konoyama, Abiko-shi, Chiba 270–1145, Japan 5 1–11–11 Midori, Abiko-shi, Chiba 270–1153, Japan 6 Yamashina Institute for Ornithology, 115 Konoyama, Abiko-shi, Chiba 270–1145, Japan 7 Japanese Association for Wild Geese Protection, 16 Minami-machi, Wakayanagi, Kurihara-shi, Miyagi 989–5502, Japan

ORNITHOLOGICAL Abstract We satellite-tracked Whooper Swans Cygnus cygnus wintering in north- ern Japan to document their migration routes and timing, and to identify breeding SCIENCE areas. From 47 swans that we marked at Lake Izunuma-Uchinuma, Miyagi Pre- © The Ornithological Society fecture, northeast Honshu, and at , east , we observed 57 of Japan 2014 spring and 33 autumn migrations from 2009–2012. In spring, swans migrated north along Sakhalin Island from eastern Hokkaido using stopovers in Sakhalin, at the mouth of the Amur River and in northern coastal areas of the . They ultimately reached molting/breeding areas along the Indigirka River and the lower Kolyma River in northern Russia. In autumn, the swans basically reversed the spring migration routes. We identified northern Honshu, eastern Hokkaido, coastal areas in Sakhalin, the lower Amur River and northern coastal areas of the Sea of Okhotsk as the most frequent stopover sites, and the middle reaches of the Indigirka and the lower Kolyma River as presumed breeding sites. Our results are helpful in understanding the distribution of the breeding and stopover sites of Whooper Swans wintering in Japan and in identifying their major migration habitats. Our findings contribute to understanding the potential transmission process of avian influenza viruses potentially carried by swans, and provide information necessary to conserve Whooper Swans in East Asia.

Key words Cygnus cygnus, Indigirka River, Kolyma River, Lake Izunuma- Uchinuma, Lake Kussharo, Migration route, Satellite-tracking, Whooper Swan

Whooper Swans Cygnus cygnus breed widely at (Received 13 March 2013; Accepted 22 July 2014) boreal lakes and along rivers of northern Eurasia, # Corresponding author, E-mail: [email protected] from Iceland in the west to easternmost Russia and * Present address: Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Bunkyo-machi even the outer Aleutian Islands in the east (Brazil 1–14, Nagasaki 852–8521, Japan 2003). Their wintering range in East Asia includes ** Present address: Graduate School of Media and Governance, Kamchatka (Gerasimov 2001), Japan, South Korea Keio University SFC, Endo 5322, Fujisawa-shi, Kanagawa and China. Japan supports the largest number of win- 252–0882, Japan *** Present address: Faculty of Agriculture, Iwate University, tering Whooper Swans in East Asia (Cao et al. 2008) 3–18–8 Ueda, Morioka-shi, Iwate 020–8550, Japan with 26,621 counted in January 2013 (Ministry of

67 T. SHIMADA et al. the Environment of Japan 2013), which was about autumn migration was not studied. 44% of the estimated East Asian-Australasian Fly- In order to obtain more detailed information on the way population (Wetlands International 2006). migration patterns of Whooper Swans, we attached Whooper Swans have expanded their breeding satellite transmitters to 47 swans (21 males, 25 range in some regions in Russia (Syroechkovski females, 1 unknown; 39 adults and 8 juveniles) on 2002). In the early 1980s, molting and breeding con- their wintering grounds in northern Japan. Here, we centrations of Whooper Swans were observed along describe their migration routes, the distribution of the lower Indigirka River, and breeding was con- stopovers and potential breeding sites, and the pat- firmed in the forest-tundra at latitudes of 69°–70°N. terns of spring and autumn migrations. Our findings In the 1990s, breeding was also confirmed in arctic contribute to understanding the potential transmission landscapes. The increase in the population and the process of avian influenza viruses through swans, and expansion of its breeding range can be partly attrib- provide information necessary to conserve Whooper uted to conservation efforts in Japan (Albertsen & Swans in East Asia. Kanazawa 2002). However, Koyama et al. (2013) also suggested that rising temperatures in the breed- MATERIAL AND METHODS ing range could also be responsible for the increase seen among Whooper Swans wintering in Japan. To 1) Satellite tracking understand the mechanism underlying the expansion A total of 47 Whooper Swans was captured during of their Russian breeding range and their increas- the 2008–2009 and 2009–2010 winters at two sites ing population size in East Asia, it is necessary to in Japan: Lake Kussharo (43°38′N, 144°22E′), east understand the connection between the breeding and Hokkaido, and Lake Izunuma-Uchinuma (38°43′N, wintering grounds of Whooper Swans at the indi- 141°07′E), Miyagi Prefecture, northeast Honshu (Fig. vidual level. 1). Of these 47, 14 were captured at Lake Kussharo Wild birds, in particular waterfowl, play a role on (19–20 January 2009), with the remaining 33 caught the circulation of influenza A virus. They often carry at Lake Izunuma-Uchinuma (28 on 11–12 February low pathogenic avian influenza (LPAI) viruses (Olsen 2009, and five on 17–19 January 2010). Swans were et al. 2006), and infected individuals may potentially captured by means of flat net traps and by hand. spread LPAI viruses over wide areas, since many The swans were marked with neck collars to which species migrate long distances between their breed- satellite transmitters (platform transmitter terminals; ing and wintering grounds. In Asia, migrating wild PTTs) had been glued. The neck collars were made birds have been suspected of spreading the highly of non-UV resistant plastic, therefore we anticipated pathogenic H5N1 avian influenza virus over long that they would fall off when the collar material dete- distances (Chen et al. 2006). Five Whooper Swans riorated after two or three years. We used solar- and found dead during April and May 2008 in Hokkaido, battery-powered PTTs (North Star Science and Tech- Aomori, and Akita Prefectures, Japan, were infected nology) weighing 12, 20 and 23 g, and solar-pow- with H5N1 avian influenza (Ministry of the - Envi ered PTTs (Microwave) weighing 18 g. The PTTs ronment of Japan 2011). Thus, Whooper Swans are were designed to transmit from 2–5 years, depend- a species of concern with respect to exposure and ing on conditions. The total weight of the collars transmission of avian influenza viruses. with attached PTTs ranged from 47 to 58 g. At the Information on the migration routes and move- time of capture, the body mass of the birds ranged ment patterns of Whooper Swans in East Asia includ- from 8,110–12,300 g, thus the attached collars and ing Japan is limited. Satellite tracking, which can PTTs amounted to less than 0.7% of individual body provide basic information on the movement patterns weights. Special thin plastic neck bands were used of marked individuals, contributes to understanding for this study in order to reduce weight (Yamashina migration. Kanai et al. (1997) satellite-tracked eight Institute for Ornithology, pers. comm.). Whooper Swans on their spring migration from north- The PTT locations were estimated by means of ern Japan via Sakhalin and the lower Amur River, to the Argos system (Argos 1996) and were reported as their potential breeding areas along the lower Amur latitude and longitude (WGS84 datum), with location River, the north coast of the Sea of Okhotsk, the times recorded as Greenwich Meridian Time (GMT). middle reaches of the Indigirka River and the lower Argos classified the location accuracy (location class, Kolyma River. Their sample size was limited and LC) into 3, 2, 1, 0, A, B and Z. The standard devia-

68 Satellite tracking of Whooper Swans

over sites, and duration of stay at the stopover sites. A stopover site was defined as an area used after departure from a wintering/terminal site where a PTT recorded adjacent locations for at least 24h within a period where data were continuously obtained over more than five days. We used these criteria to ensure that we had sufficient location data to discern when a bird was truly at a stopover site. A terminal site was defined as a site at the northern end of a spring migration route where a bird stayed for more than three months. We suspect that most terminal sites represented breeding or molting locations. Female Whooper Swans incubate their eggs for 31–42 days (Kear 2005), and males remain with their mates dur- ing that period (Brazil 2003). In addition, the post- breeding flightless period lasts 4–6 weeks from late June to early September during which they shed and re-grow their wing feathers (Brazil 2003). Thus, we considered that swans were at a molting site if they remained for a period of more than four weeks with little movement. Because some PTT data was intermittent, we could not always determine an individual’s exact departure or arrival dates. When the exact date of a migra- tion movement could not be determined, we used the middle date within the range of possible dates (the Fig. 1. Important migration sites of Whooper Swans as indi- possible range is between the date of the last location cated by satellite telemetry. Stars indicate capture sites in obtained at a site and the date of the first location Japan where satellite transmitters were deployed (upper: Lake away from that site). If there were an even number of Kussharo, lower: Lake Izunuma-Uchinuma). White circles show stopover sites and black squares show terminal sites. days in the potential range, we used the later of the two most central dates. We did not estimate arrival or departure dates if the potential range of dates was of tion of positional error on the latitudinal and longi- more than five days. tudinal axes was <150 m for LC 3, 150–350 m for LC 2, 350–1,000 m for LC 1, and >1,000m for LC RESULTS 0; the location accuracy for LCs A, B and Z could not be determined. Since other studies have reported 1) Spring migration that the approximate accuracy of LC 0 is within 10 Because some PTTs transmitted for more than km (Brothers et al. 1998; Britten et al. 1999; Hays et one year, we observed a total of 18 spring migra- al. 2001), the standard deviation may have been less tions from 14 swans marked at Lake Kussharo and than 5 km for LC 0. We used the locations of LCs 39 spring migrations from 33 swans marked at Lake 0 to 3 to determine the migration routes of marked Izunuma-Uchinuma. All data involved swans that swans. Since swans move thousands of kilometers were successfully tracked from wintering sites to ter- during migration, location errors of <10 km can be minal sites during 2009–2012. Some of the PTTs considered negligible when describing migration stopped functioning for unknown reasons shortly routes and the location of stopovers at a large scale. after the birds were released. Most swans from Lake Kussharo migrated first to Aniva Bay in southern 2) Statistical analyses Sakhalin, then to Sakhalin Bay in northern Sakhalin For spring and autumn migration, we determined: and the lower Amur River on the adjacent Asian con- departure and arrival dates at wintering/terminal tinent (Figs. 1, 2). The swans from Lake Izunuma- sites (see below), the number and locations of stop- Uchinuma moved first to eastern Hokkaido via Iwate

69 T. SHIMADA et al. and Aomori Prefectures, except for two birds that from Lake Kussharo (late March to mid May), yet migrated via north Hokkaido in spring 2009. Most the arrival dates at the terminal sites were similar for swans migrated via Sakhalin to the lower Amur River, swans from both wintering sites (Table 1). The mean then subsequently crossed the Sea of Okhotsk, even- number of stopover sites was 1.9–2.5, and the period tually reaching tundra regions in northeastern Russia. of stay at any given stopover site was 13.4–15.7 Some swans stopped over in northern coastal area of days. On average, the swans from Lake Kussharo Russia along the Sea of Okhotsk. One swan moved traveled 3,082.4 km (N=20), and required a mean of to the Kamchatka Peninsula after crossing the Sea 36.9 days (N=14) to complete their migration. The of Okhotsk directly from southern Sakhalin in 2009. mean travel distance and duration for the swans from Stopover sites included the Kitakamigawa River in Lake Izunuma-Uchinuma was 3,794.2 km (N=60) Iwate Prefecture, , Notsuke Peninsula and and 86.3 days (N=38). The distance between the two Lake in eastern Hokkaido, Aniva Bay and capture sites was 610 km. Sakhalin Bay in Sakhalin, the lower Amur River and The potential breeding and molting sites were dis- northern coastal areas of the Sea of Okhotsk. tributed along the middle reaches of the Indigirka The estimated departure dates (mid February to and the lower Kolyma River in northern Russia. mid March) for the swans from Lake Izunuma- The average length of stay in those terminal sites Uchinuma were one or two months earlier than those was 111.1 days (N=14) for the swans from Lake

Fig. 2. Spring migration routes of Whooper Swans marked with satellite transmitters at two wintering sites (Lake Kussharo and Lake Izunuma-Uchinuma) in Japan in 2009–2012.

Table 1. Capture sites, range and median dates of departure dates from capture or terminal sites, arrival dates at terminal or capture sites, mean duration (±SD) of staying at stopover sites, and mean number (±SD) of stopover sites. The methods of calculating each statistic are described in the Methods section. Numbers in parentheses indicate sample sizes.

Departure date from Arrival date at Duration at Number of Season Capture site capture/terminal sites terminal/capture sites stopover sites (days) stopover sites Lake Kussharo 3/22–5/14, 4/21 (14) 5/5–6/30, 5/20 (16) 13.4± 8.6 (25) 1.9±0.8 (13) Spring Lake Izunuma-Uchinuma 2/14–3/14, 2/25 (23) 5/2–6/10, 5/16 (33) 15.7±11.6 (84) 2.5±1.6 (33) Lake Kussharo 9/7–10/6, 9/28 (11) 10/8–12/23, 10/30 (7) 17.1±12.1 (9) 1.5±0.5 (6) Autumn Lake Izunuma-Uchinuma 9/15–10/12, 10/5 (20) 10/23–1/14, 12/18 (7) 22.9±24.7 (13) 1.9±0.6 (7)

70 Satellite tracking of Whooper Swans

Kussharo and 135.2 days (N=28) for the swans from those wintering at Lake Izunuma-Uchinuma. The Lake Izunuma-Uchinuma. mean number of stopover sites was 1.5–1.9, and the period of stay at any given stopover site was 17.1– 2) Autumn migration 22.9 days. The swans wintering at Lake Kussharo We tracked a total of 12 autumn migrations of moved an average of 2,984.1 km (N=12), and took 14 swans marked at Lake Kussharo and 21 autumn 39.7 days (N=7) to arrive. For the swans wintering migrations of 33 swans marked at Lake Izunuma- at Lake Izunuma-Uchinuma, the mean travel distance Uchinuma during 2009–2012. Fourteen swans were was 3,454.5 km (N=22) taking 53.8 days (N=6). tracked during both spring and autumn migration Whooper Swans were found to utilize similar within a year. Of those 14, one was tracked succes- migration routes in both spring and autumn (Figs. 2, sively for two years and the other for four years. 3), although the distribution of stopover sites differed In autumn, the swans essentially retraced their somewhat between seasons. They stopped over in spring migration routes, reaching Sakhalin Bay in both southern and northern coastal areas of Sakhalin northern Sakhalin and the lower Amur River after in spring, but bypassed the southern coastal areas crossing the Sea of Okhotsk (Figs. 1, 3). Some birds in autumn. Also, in autumn, many swans bound for stopped over in northern coastal areas of the Sea Lake Izunuma-Uchinuma moved directly to Miyagi of Okhotsk. After departing their Russian stopover Prefecture without stopping in eastern Hokkaido, sites, the swans from Lake Kussharo returned to despite having visited there in spring. Neither the eastern Hokkaido, while many swans wintering at migration routes nor the distribution of stopover sites Lake Izunuma-Uchinuma, in Miyagi Prefecture, flew and potential breeding sites of the swans differed their directly without stopping in Hokkaido. Stopover between years; however, the number of swans being sites were widely distributed across Sakhalin Bay, the tracked rapidly decreased from 56 in 2009 to 5 in lower Amur River, and northern coastal areas of the 2012 as transmitters failed (Figs. 2, 3). Sea of Okhotsk. Although the Whooper Swans wintering at Lake DISCUSSION Kussharo and Lake Izunuma-Uchinuma shared sim- ilar estimated departure dates from their potential 1) Spring migration breeding sites in Russia (Table 1), those wintering at After departing Japan, the Whooper Swans Lake Kussharo arrived there one month earlier than migrated north via coastal areas of Sakhalin to the

Fig. 3. Autumn migration routes of Whooper Swans marked with satellite transmitters at two wintering sites (Lake Kussharo and Lake Izunuma-Uchinuma) in Japan in 2009–2012.

71 T. SHIMADA et al. lower Amur River and subsequently across the Sea (Yamashina Institute for Ornithology 2002). Of the of Okhotsk to northeastern Russia. Our data from 10 recovery sites recorded in Russia, six were located 47 birds validate Kanai et al.’s (1997) previous con- in Sakhalin, two in Khabarovsk and two in Yakutia. clusions, based on a much smaller sample of eight All recovery sites, except for those of two birds from marked birds, with regards to the route of the spring Yakutia, were distributed along the migration routes migration. revealed by our study. In addition to the birds we tracked by satellite, Autumn stopover sites were in northern coastal three of our study birds were recovered dead in areas of the Sea of Okhotsk in Sakhalin Bay, and Russia, all were from among those marked at Lake along the lower Amur River. The distribution of Izunuma-Uchinuma (Yamashina Institute for Orni- the stopover sites differed slightly between seasons. thology, pers. comm.). One adult male was collected The marked swans bypassed southern coastal areas at Lankovaya River, Magadan, on 23 May 2012, and of Sakhalin that they had used in spring, and some one at Marekan Cape, Khabarovsk, on 15 May 2012. also bypassed eastern Hokkaido on their way to Lake One adult female was found at Pobedino, Sakhalin, Izunuma-Uchinuma in Miyagi Prefecture. on 9 May 2011. These recovery sites were distributed It is possible that seasonal climatic conditions along the spring migration route confirmed by this result in the differences in the stopover locations study. used between spring and autumn. Whooper Swans Based on our satellite tracking data and results wintering in Japan have been frequently observed from Kanai et al. (1997), we conclude that the to forage for aquatic plants, especially the rhizomes Kitakamigawa River in northern Honshu, Lake of Zizania latifolia, and rice grains in paddy fields Furen, Notsuke Peninsula and in (Shimada 2007; Watanabe et al. 2008). Ice and snow eastern Hokkaido, Aniva Bay in southern Sakhalin, cover make foraging for these foods difficult (Ueta and Sakhalin Bay in northern Sakhalin, the lower 2007). The swans from Lake Izunuma-Uchinuma Amur River, and northern coastal areas of the Sea of appeared to migrate north gradually as the spring Okhotsk are the main stopover sites of the Whooper thaw progressed, while that constraint did not exist Swans that winter in Japan. These stopover sites were in autumn. Perhaps for this reason the swans bypass located at wetlands and lakes, in coastal areas, at certain stopover sites in autumn. the mouths of rivers, and in various bays. We found Newman et al. (2009) satellite-tracked the migra- that marked swans migrated more than 3,000 km and tion of 10 Whooper Swans from molting sites in used a relatively small number of stopover sites. northeastern Mongolia in autumn 2006. Five of them The potential breeding sites were distributed along were tracked throughout their migration; four moved the middle reaches of the Indigirka and the lower southeast to winter along the Korean Peninsula, and Kolyma River in the forest-tundra zone. Kanai et one used a more westerly route to the Shandong al. (1997) suggested that breeding sites were distrib- Peninsula, China, showing that at least some of the uted along the lower Amur River, the north coast of swans summering in northeastern Mongolia winter the Sea of Okhotsk, along the middle reaches of the on the Korean and Shandong Peninsulas. It seems, Indigirka River, and the lower Kolyma River. More- therefore, that the migration routes, stopover sites, over, of the 10 recovery sites recorded in Russia, and breeding areas differ between the swans win- two were in Yakutia (Yamashina Institute for Orni- tering in Japan and on the Korean Peninsula and thology 2002), i.e. within the potential breeding area in China. By collecting more information based on suggested by our study. These data strongly suggest satellite tracking, we expect to improve our under- that the middle reaches of the Indigirka River and standing of the migration routes and patterns of the the lower Kolyma River in the northern tundra are Whooper Swans wintering in East Asia and hence of also breeding sites for Whooper Swans that winter the potential transmission process of avian influenza in Japan. viruses by swans. The migration routes, and the distribution of stop- 2) Autumn migration over sites and potential breeding sites were found Satellite tracking of Whooper Swans indicated that not to differ greatly among individual Whooper they utilized similar migration routes in autumn as Swans. Conversely, ducks such as Mallard Anas in spring and our data coincided with band-recov- platyrhynchos and Northern Pintail A. acuta that also ery data from swans marked in Japan since 1961 winter widely in Japan originate from breeding areas

72 Satellite tracking of Whooper Swans that are widely distributed across eastern Asia, and ever their breeding grounds were presumed to be they follow diverse migration routes (Yamaguchi et located farther north than those of Whooper Swans al. 2008; Hupp et al. 2011). Such differences in the (Higuchi et al. 1991). migration routes linking breeding and wintering areas These combined results for the two swan species between ducks and swans may reflect the effects of that winter in Japan indicate the overall importance social learning on migration strategies (Mueller et of the lower Amur River, coastal areas of Sakhalin, al. 2013). Whooper Swans migrate in autumn and and northern coastal areas of the Sea of Okhotsk as spring in family groups that consist of mated pairs key stopover sites for East Asian waterfowl. Indus- and their offspring, facilitating learning of migration trial development, proposed for some of these stag- routes (Brazil 2003). In contrast, male ducks abandon ing areas, presents potentially wide-ranging conse- their mates during early incubation (Austin & Miller quences for their populations. The swans marked in 1995) and there is little family cohesion during either this study used only a relatively small number of migration. The strength of the social relationships stopover sites, and those areas may be the subject of between individuals in a family may thus promote industrial development. Our study provides informa- the tendency for swans to migrate along more clearly tion on areas that may be of concern. defined migration routes. By determining the important habitats along a The number of tracked swans decreased through species’ flyway, we can assess the roles and- rela time as transmitters failed or collars were lost. For tive importance of different sites used by a species example, one broken collar with its attached trans- through distribution and population trends along mitter was found on a field near Lake Izunuma- their flyway, and explore suitable habitat manage- Uchinuma in 2010–2011. ment methods through a combination of nationwide monitoring surveys and local-scale studies at each of 3) Conservation of swans in East Asia the important sites (Higuchi 2012). We identified northern Honshu, eastern Hokkaido, Five Whooper Swans found dead in northern coastal areas of Sakhalin, the lower Amur River and Japan in 2008 were infected with H5N1 avian influ- northern coastal areas of the Sea of Okhotsk as stop- enza (Ministry of the Environment of Japan 2011). over sites, and the middle reaches of the Indigirka The swans are considered a species of concern with and the lower Kolyma River as presumed breed- respect to exposure and transmission of such viruses. ing sites for Whooper Swans wintering in Japan. The spring and autumn migration routes described in The migration routes and staging areas of Whooper this study provide essential information to infer the Swans at least partially overlapped with those of potential patterns of transmission of avian influenza Tundra Swans C. columbianus. In Japan, four Tundra viruses by the Whooper Swans wintering in Japan. Swans were tracked from Lake Kuccharo, Hokkaido We revealed that several stopover sites are important (45°10′N, 142°20′E) in 1990 (Higuchi et al. 1991). areas for the swans we satellite-tracked. To evaluate They moved north over Sakhalin stopping in north- the potential for virus transmission among the swans ern Sakhalin or near the mouth of the Amur River. from different wintering sites, we plan to examine They finally reached the area around the mouth of the detailed spatial distribution of stopover sites, and the Kolyma River. Eight Tundra Swans wintering whether (and how) swans from differing wintering at Lake , Tottori and Shimane Prefectures sites share those areas spatio-temporally. (133°06′N, 35°10′E) in southwestern Japan, followed at least two spring migration routes: one followed ACKNOWLEDGMENTS the Japanese islands whereas the other crossed the Sea of Japan. Two of three swans that crossed the We thank Y. Abe, E. Morishita, S. Moriguchi, S. Kasahara, Sea of Japan staged at the mouth of the Amur River S. Konno, M. Konno, S. Mori, F. Nakayama, A. Ogawara, K. (Kamiya & Ozaki 2002). Tundra swans from both Takagi, K. Takano, and K. Tamada for help with capturing swans. This research was funded by the Ministry of the Envi- Lake Kuccharo and Lake Nakaumi staged at the ronment of Japan, the Ministry of Education, Culture, Sport, mouth of the Amur River and along east and west Science and Technology of Japan, the U.S. Geological Survey coasts of Sakhalin, indicative of their importance as Alaska Science Center and the U.S. Fish and Wildlife Service. stopover sites for Tundra Swans wintering in Japan. Any use of trade name is for descriptive purposes only and Tundra Swans wintering in Japan followed similar does not imply endorsement by the U.S. Government. migratory routes in spring as Whooper Swans, how-

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