Kanai, Y., F. Sato, M. Ueta, J. Minton, H. Higuchi, M. Soma, N. Mita, S. Matsui. 1997. The migration routes and important restsites of Whooper Swans satellite-tracked from northern Japan. Strix 15: 1-13. Introduction Whooper Swans Cygnus cygnus are large birds of marshlands and lakes. They migrate long distances and stop over at several rest sites on their way. They need extensive marshes for existence, but their habitats have been decreasing and deteriorating worldwide in recent years. As a result, their population has decreased in East Asia (AWB & IWRB 1994). There is a lack of information on the migration routes of Whooper Swans. Banding work has been conducted in Japan, but only fragmentary data have been collected on migration routes (Yamashina Institute for Ornithology 1991, 1992). There is little information on which to base effective conservation measures for swans. Satellite tracking is an effective way to track moving objects over long distances, and has recently been used to show the migration routes and ecology of birds (Jouventin & Weimerskirch 1990, Nowak et al. 1990, Higuchi et al. 1991, 1992, 1994a, b). Satellite tracking data has been used for conservation of cranes (Higuchi et al. 1996). We initially satellite-tracked Whooper Swans in 1991, but we could not successfully track them from their wintering site to their breeding grounds because all transmitters were broken by the swans (Higuchi et al. 1992). We satellite-tracked Whooper Swans again in 1994-1995 and some of the swans with transmitter were successfully tracked to their breeding grounds in Russia. This paper reports the migration routes and important stopover sites along the routes, and compares the migration routes between Whooper and Whistling C. columbianus Swans. Study area and methods Whooper Swans were captured on the Kominato sea coast (40.94゜N, 140.98゜E), northern Honshu, Japan in 1994 and 1995. Kominato is a well-known wintering site of Whooper Swans, and is designated as a national natural monument because of them. Recently, about 400-500 Whooper Swans winter at Kominato each year. One transmitter was attached to each of 6 swans on February 21, 1994, and each of 9 swans on February 23, 1995. The transmitter was developed by the Nippon Telegraph and Telephone Corporation (NTT) and Toyo Communication Equipment Co., Ltd. (TOYOCOM). The transmitter used in 1994 (T-2050) was 60 x 40 x 30 mm in size with an antenna of 18 cm, and weighed 80 g. The transmitter used in 1995 (T-2050) was 70 x 34 x 23 mm in size with an antenna of 18 cm, and weighed 65 g. The transmitter was attached to the backs of swans with Teflon treated ribbon. The ribbon was put through the holes in the transmitter’s flanges, and crossed at the swan’s breast. Both ends of the ribbon were fixed with rivets. All transmitters in 1994, and 7 of 9 transmitters in 1995, cycled at 6 hours active and 12 hours inactive, and the pulse interval was 60 seconds. The battery life was expected to be 6 months. The two remaining transmitters in 1995 cycled at 6 hours active and 42 hours inactive, and the pulse interval was 60 seconds. The battery life was expected to be one year. Location data were received through computer communications and on disks sent from the CLS/Service Argos in France. Location classes ranged from 0 to 3. The higher the location class, the more accurate the location. Keating et al. (1991) calculated the accuracy of LC 1, 2 and 3 data from PTTs designed for ungulates and wolves. Their one-standard-deviation accuracy results, compared to the accuracies reported by the CNES/Argos (1992) were, respectively, 1,188 m versus 1,000 m for LC 1, 903 m versus 350 m for LC 2, and 361 m versus 150 m for LC 3. In our analyses we assume an accuracy of 1 km for all data of LC 1 and above. Location class 0 data were included to show the general migration route when the locations were considered appropriate from the nearest locations and elapsed time. They were, however, excluded from the analysis when more accurate locations were required. Place names are based on ONC maps of the Defense Mapping Agency Aerospace Center. Results and Discussion Migration Routes 1. 1994 tracking A total of 1,823 locations were obtained from February 21 to August 21. Of the 6 Whooper Swans, 3 were successfully tracked to their breeding grounds in Russia (Fig. 1). They migrated from Kominato to their breeding sites via southeastern Hokkaido, northeastern Hokkaido, Sakhalin and the lower Amur River. Two individuals spent the summer on the lower Amur River, and an individual spent the summer on middle reaches of the Indigirka River. Their migration routes are described as follows. ID 1288 was tracked from February 21 to June 12, and we received 368 locations. It was located for the last time in Kominato on March 15. Next, the swan was located at Oikamanae-numa Lake (42.57゜-42.58゜N, 143.46゜-143.50゜E) on the morning of March 17. The night of March 17, it arrived on the Tokachi River (42.74゜-42.90゜N, 143.41゜-143.61゜E) where it rested for 25 days, before being located at Abashiri Lake (43.88゜- 43.93゜N, 144.13゜-144.18゜E) on the morning of April 11. It was located north of Svobodnoye (46.91゜N, 143.37゜E), southern Sakhalin on April 13, and at central Aniva Bay (46.70゜-46.78゜N, 142.65゜-142.77゜E) on the morning of 14th, where it rested for 16 days. The night of May 1, it stayed at Buruny (48.08゜-48.11゜N, 142.55゜-142.58゜E), and N. Pogibi City (52.41゜-52.44゜N, 141.73゜-141.78゜E), central Sakhalin, on the night of the 5th. The swan left there and traveled to the lower Amur River (52.47゜-52.53゜N, 140.66゜-140.80゜E) on the night of May 9, where it was located until its PTT quit on June 13. ID 21416 was tracked from February 23 to August 21, and we received 765 locations. It was located for the last time in Kominato on March 30. Next, the swan was located at the Oikamanae-numa Lake (42.61゜N, 143.52゜E) on the night of March 31. The afternoon of April 1, it stayed on the Tokachi River (42.79゜-42.82゜N, 143.51゜- 143.60゜E), and rested there for 10 days. The swan was located at Saroma Lake (44.10゜N, 143.93゜E) on the morning of April 12. It was located in central Aniva Bay (46.71゜-46.74゜N, 142.71゜-142.75゜E), southern Sakhalin, on the night of 12th, and moved to eastern Aniva Bay (46.51゜-46.54゜N, 143.29゜-143.34゜E) on the night of the 18th. The swan rested there for 13 days, and then flew to Aynskoye Lake (48.49゜-48.56゜N, 142.00゜-142.05゜E) on the afternoon of May 1, where it rested for 6 days. The swan was located at the Tatarskiy Strait (51.53゜-51.54゜N, 141.41゜-141.42゜E) on the afternoon of May 7, and at Uarke (52.48゜N, 141.10゜E) on the morning of the 9th. That day it flew to the lower Amur River (52.19゜N, 140.24゜E), where it rested for 20 days within the marsh (52.25゜-52.29゜N, 140.31゜-140.40゜E; and 53.13゜-53.17゜N, 140.41゜-140.50゜E; 53.06゜-53.20゜N, 139.50゜-139.67゜E). It was located at N. Okhotsk City (59.97゜-60.02゜N, 144.00゜-144.16゜E) on the night of May 30, and stayed there for 8 days before being located at the upper reaches of Indigirka River (62.84゜-62.88゜N, 144.33゜-144.45゜E) on June 6. Next, the swan was located at several places along the upper Indigirka River at (64.79゜- 64.81゜N, 144.84゜-144.91゜E) on June 9, (65.71゜-65.76゜N, 146.12゜-146.26゜E) on June 12, and a near Tyugyuren City (67.23゜-67.33゜N, 142.55゜-142.56゜E), middle reaches of Indigirka River, on June 14. The swan traveled to wetlands along that river (67.85゜-67.92゜N, 143.25゜-143.52゜E) on June 18, and the swan was located there until its PTT quit on July 25. ID 21417 was tracked from February 24 to August 7, and we received 238 locations. It was located for the last time in Kominato on March 29. Next, the swan was located at the Oikamanae-numa Lake (42.56゜-42.57゜N, 143.49゜E) on the morning of March 31. The afternoon of April 1 it arrived at the Tokachi River (42.81゜-42.92゜N, 143.40゜-143.53゜E), and rested there for 25 days before being located at Saroma Lake (44.19゜N, 143.58゜E) on the morning of April 26. It was located in eastern Aniva Bay (46.53゜-46.54゜N, 143.28゜-143.32゜E), southern Sakhalin, on the morning of April 28. On May 1 the swan was located in Buruny (48.06゜-48.11゜N, 142.54゜-142.58゜E), and west of Poronaysk (49.13゜N, 143.04゜E), central Sakhalin, on the morning of the 9th. The swan moved to the lower Amur River (52.91゜-53.03゜N, 139.46゜-139.62゜E) on May 10 where it was located until its PTT quit on June 23. 2. 1995 tracking A total of 1,433 locations were obtained from February 23 to August 9. Of the 9 Whooper Swans, 5 were successfully tracked to their breeding grounds in Russia (Fig. 2). They migrated from Kominato to their breeding sites via southeastern Hokkaido, northeastern Hokkaido and Sakhalin. Two individuals summered on the north coast of the Okhotsk Sea, two individuals spent the summer on middle reaches of the Indigirka River, and an individual spent the summer on lower Kolyma River. Their migration routes are described as follows. ID 22907 was tracked from February 23 to May 24, and we received 122 locations. It was located for the last time in Kominato on March 26. Next, the swan was located at Shizunai (42.40゜-42.41゜ N, 142.37゜-142.44゜E) on the night of March 27, and rested there for 18-24 days. The night of April 20, it stayed on the Tokachi River (42.81゜-42.82゜N, 143.52゜-143.54゜E), and rested there for 11-17 days before being located at the Nevskoye Lake (49.62゜N, 143.48゜E), central Sakhalin, on the night of May 2. It was located in N. Pogibi (52.58゜-52.63゜N, 141.83゜-141.84゜E), northern Sakhalin, on the morning of May 6, and rested there for 11 days. The swan traveled to N.W. Motykleyka (59.81゜-59.83゜N, 147.74゜-147.83゜E) on May 18, and was located there until its PTT quit on May 24. ID 22908 was tracked from February 23 to May 27, and we received 297 locations. It was located for the last time in Kominato on March 8. Next, the swan was located at the Lake Obuchi-numa (40.96゜-40.97゜N, 141.37゜-141.39゜E) on the night of March 9, and rested there for 5 days. It was located at Furen Lake (43.32゜N, 145.35゜E) on the night of March 14. It was located at Notsuke Peninsula (43.59゜-43.65゜N, 145.05゜-145.32゜E) on the night of the 18th, and stayed there for 23-26 days. On April 11, the swan was located at Abashiri Lake (43.91゜-43.93゜N, 144.14゜-144.19゜E), and rested there for 15-16 days. It was located near Polonysk City on the afternoon of April 28, S. Pogibi City (51.82゜N, 141.82゜E) on the 29th, and the northern end of Sakhalin (54.52゜-54.53゜N, 142.59゜-142.62゜E) on the 30th. Next, the swan was located in W. Motykleyka (59.57゜-59.60゜N, 146.49゜-146.53゜E) on May 3, and rested there for 8 days. On the morning of May 13, it reached the upper Indigirka River (65.20゜-65.37゜N, 146.70゜-146.85゜E), and stayed there for 6 days. The swan traveled to wetlands along that river (67.91゜-61.94゜N, 145.58゜-145.72゜E) on May 21, and was located there until its PTT quit on May 27. ID 23393 was tracked from February 25 to June 21, and we received 135 locations. It was located for the last time in Kominato on April 8. Next, the swan was located on the Tokachi River (42.74゜-42.84゜ N, 143.49゜-143.65゜E) on the night of April 10, and rested there for 18-22 days. The swan was located in N. Polonysk City (49.57゜N, 143.11゜E) on the night of May 2, and located in Pil’tun Lake (52.83゜N, 143.32゜E) on the night of the 6th. On May 8, the swan was located on the upper Kolyma River (64.71゜-64.72゜N, 151.61゜-151.70゜E), and rested there for 2-4 days. It was located in wetlands along the Indigirka River (69.39゜-69.79゜N, 147.32゜-147.96゜E) on the afternoon of May 12, and was located there until its PTT quit on June 21. ID 23394 was tracked from February 25 to June 17, and we received 60 locations. It was located for the last time in Kominato on March 29. Next, the swan was located in eastern Aniva Bay (46.53゜-46.57゜N, 142.24゜-142.32゜E) on the night of April 8, and rested there for 22-34 days. The swan was located in N.W. Polonysk City (49.55゜N, 142.96゜E) on the night of May 6, and in the lower Amur River (52.85゜-52.95゜N, 139.53゜-139.72゜E) on the afternoon of the 8th. The swan rested there for 32-34 days, and flew to the Amur River mouth on the afternoon of June 11 (53.08゜N, 141.27゜E). On June 17, the swan was located near Okhotsk City (59.24゜-59.26゜N, 142.60゜-142.67゜E), and the transmitter quit that night. ID 23395 was tracked from February 23 to August 8, and we received 515 locations. It was located for the last time in Kominato on April 7. On the afternoon of April 9, the swan was located at Akkeshi Lake (42.99゜-43.08゜N, 144.86゜-144.95゜E), and flew to Furen Lake (43.32゜N, 145.24゜E) on the morning of April 11, and to Tokotan River (43.43゜N, 145.24゜E) that night. It was located in central Aniva Bay (46.60゜-46.77゜N, 142.69゜-142.74゜E) on the night of April 14, and moved to eastern Aniva Bay (46.66゜-46.77゜N, 143.31゜-143.38゜E) on the night of the 25th. The swan rested in Aniva Bay for 21 days, and flew to Starodubskoye (47.43゜N, 142.73゜E) on the afternoon of May 4. On the night of May 5, the swan was located at Molodezhnoye (51.04゜N, 142.60゜-142.62゜E), and moved to Udyl Lake, lower Amur River (51.62゜-51.92゜N, 139.53゜-139.80゜E) on the morning of the 7th. The swan rested there for 22 days, and flew to the Amur River mouth (53.33゜N, 141.21゜E) on the morning of the 29th. It flew to N.E. Inya City (61.44゜N, 146.90゜E) on the night of May 30, and to the upper reaches of the Kolyma River (65.66゜-65.75゜N, 150.52゜-150.73゜E) on the night of the 31st. The swan stayed there for 7 days before being located on the middle reaches of Kolyma River (67.45゜N, 152.02゜E) on the morning of June 9. On the morning of June 10, the swan was located in wetlands along the Kolyma River (69.34゜-69.44゜N, 152.38゜-152.76゜E), where it was located until its PTT quit on August 9. 3. Summary migration route of Whooper Swans The migration routes of Whooper Swans were similar between results in 1994 and 1995. They migrated from Kominato to southeastern Hokkaido, and rested there for a long time. They moved to Aniva Bay, Sakhalin, via northeastern Hokkaido, and also rested their for a long time. They went north along Sakhalin, and rested on the lower Amur River for a long time. Some individuals spent the summer there. They crossed the Okhotsk Sea, and moved to breeding areas. Important Areas for Swans Table 2 shows a list of areas visited by the swans equipped with transmitters. All these areas are important for the swans, and we can evaluate the importance of each area based on the length of stay and the number of swans which visited them. Tokachi River, Aniva Bay and lower Amur River were the most important stopover areas for swans which wintered at Kominato. The swans’ stopover periods at each site are shown in Fig 3. Migration and conservation information for these areas are given below. 1. Tokachi River Five of 8 successfully tracked swans rested there, and total 6 swans rested there. They spent from 10 to 24 days each. Swans rested mainly around Ikusota Pond, where about 200 swans have been recorded roosting together and foraging in the Tokachi River during migration (Tokachi Chapter, Wild Bird Society of Japan 1986). This area is also an important stopover site for migratory Bean Geese Anser fabalis, each spring and autumn 200-550 individuals rest there (Tokachi Chapter, Wild Bird Society of Japan 1986). 2. Aniva Bay Five of 8 successfully tracked swans rested there, from 2 to 34 days each. Swans rested mainly on the north and east sides of the bay (Fig. 4). Both Whooper Swans and Whistling Swans rest in this area, with 1,000-6,000 swans being recorded there in the spring (Ostapenko 1990, Nechaev 1991). 3. Lower Amur River Five of 8 successfully tracked swans rested or spent the summer there for 20 to 40 days each, and two tracked swans spent the summer. The lower Amur River and its tributaries create a wetland complex which reaches from 51.25゜N, 139.0゜E to 53.75゜N, 141.0゜E. It is an area of lakes and marshes with little official protection. However, a portion of the area south of Bogorodskoye City is protected as a hunting preserve for indigenous people, and was visited by two tracked swans. The northern end of the wetland was used by three swans, where they visited marshes along the Amur and one of its tributaries, and in lakes to the west of the river (Fig 5). There are two primary conservation concerns for the wetland. Pollution from industrial cities upstream is likely to be a problem for waterfowl, and may account for the apparent rarity of Osprey Pandion haliaeetus along the lower Amur River. The second concern is an observed reduction of water flow due to dams on large tributaries of the middle and upper Amur River. The southern (upstream area) of the marsh is beginning to desiccate, with several small lakes having already disappeared (V. Koulikov & B. Voronov per. com.). All of the stopover sites identified are links in the migration chain, but protection of the above three areas is particularly critical for swan conservation because many of the swans rested at these sites for extended periods. Comparison of the migration route between Whooper and Whistling Swans Whooper Swans migrate from Kominato to southeastern Hokkaido, and rested there for a long time. They move to Sakhalin via northeastern Hokkaido, and go north along Sakhalin. They cross the Okhotsk Sea and move to breeding areas. The migration routes of Whistling Swans from Sakhalin to breeding areas (Higuchi et al. 1992) are similar to that of Whooper Swans. However, the migration routes from Honshu to Sakhalin are different. Whistling Swans migrate from Honshu to Sakhalin via the Japan Sea coast of Hokkaido (Yamashina Institute for Ornithology 1996). On the other hand, Whooper Swans migrate from Honshu to Sakhalin via the Pacific Ocean coast of Hokkaido. However, the migration routes of Whooper and Whistling Swans from Sakhalin to their breeding areas are similar, and there is a small difference in migration pattern. Five of 8 tracked Whooper Swans rested at Aniva Bay from 2 to 34 days each. But only 1 of 4 tracked Whistling Swans rested there for 5 days. Aniva Bay is an important rest-site for Whooper Swans rather than Whistling Swans. The lower Amur River is an important rest-site for both swan species. Five of 8 tracked Whooper Swans rested or spent the summer there for 20 to 40 days, and 2 of 4 Whistling Swans for more than 10 days each. Yamamoto, Y., & N. Seto. 1997. Decrease of summer visiting birds in Yamaguchi Prefecture analyzed from records of regular birding events. Strix 15: 15-23. 1. We analyzed the records of fifty regular birding events conducted by the Yamaguchi-ken chapter of the Wild Bird Society of Japan from 1973 to 1995 in Yamaguchi Prefecture, western Japan, plus twenty two of our own sets of observations. 2. An average occurrence-rate for each species was calculated as the number of birding trips and observations on which that species was observed, divided by the total number of birding trips and observations in each observation period. 3. A comparison of the occurence rates of summer visitors and residents was made between the periods from 1981-1985 and 1991-1995. Of the resident species, three out of 45 species were not recorded during the second observation period while, of the summer visitors, nine species out of twenty eight species were not recorded during this second period. It is clear that, of the summer visitor species, Gray-faced Buzzard-eagle Butastur indicus, Scops Owl Otus scops, Brown Hawk-owl Ninox scutulata, Jungle Nightjar Caprimulgus indicus, Gray Thrush Turdus cardis, Black Paradise Flycatcher Terpsiphone atrocaudata, House Martin Delichon urbica, Ruddy Kingfisher Halcyon coromanda and Little Tern Sterna albifrons are decreasing. Of the resident species, Hodgson's Hawk-Eagle Spizaetus nipalensis, Greater Pied Kingfisher Ceryle lugubris and White-Backed Woodpecker Dendrocopos leucotos tend to be decreasing. There is a significant difference between the occurrence rate of summer visitors and that of residents. Summer visiting species decreased more rapidly than resident species. Kawasaki, S., K. Kato, H. Higuchi, & R. Takada. 1997. Changes of breeding avifauna at Syunkunitai, eastern Hokkaido. Strix 15: 25-38. I compared the reproductive success of barn swallows between nests in semi-closed spaces and open spaces of buildings. The mean number of fledglings from nests in semi-closed spaces was larger than the number from the nests in open spaces ( semi-closed space: 3.30ｱ0.35, open space: 1.24±0.47, Mann-Whitney U=86.5, z=-3.11, P=0.02). The breeding success was higher in the semi-closed spaces than in the open spaces (Fisher's exact test, P=0.005). Main causes of breeding failure of swallows were desertion and predation. I conclude that semi-closed spaces in artificial structures provide benefits to barn swallows. It was one of the reasons why barn swallows changed their nest sites from natural to the artificial structures. Kawasaki, S., K. Kato, H. Higuchi, & R. Takada. 1997. Changes of breeding avifauna at Syunkunitai, eastern Hokkaido. Strix 15: 25-38. 1. We counted the number of birds by line census method along three trails at Syunkunitai, eastern Hokkaido, Japan, from 24 June to 6 July in 1995 and from 20 June to 1 July in 1996, and compared the number of birds to that found by Hanawa and Kurosawa (1985) in 1983. The census courses included wet grassland and forest. 2. Bird species which declined along A course were White Wagtails Motacilla alba, Siberian Rubythroats Erythacus calliope, and Black-browed Reed Warblers Acrocephalus bistrigiceps, and Yellow-breasted Buntings Emberiza aureola were extirpated. Species which declined on B course were Skylarks Alauda arvensis, Black-browed Reed Warblers, Yellow-breasted Buntings, and Long-tailed Rose Finches Uragus sibiricus. 3. Stonechats Saxicola torquata and Middendorff's Grasshopper Warblers Locustella ochotensis increased in numbers along A and B courses. This increase did not occur in response to the decline of Black-browed Reed Warblers and Yellow-breasted Buntings. 4. The decrease of Yellow-breasted Buntings and the increase of Middendorff's Grasshopper Warblers were observed in areas other than Syunkunitai. It is possible that the fluctuation of these two species occurred extensively in eastern Hokkaido. 5. Narcissus flycatchers Ficedula narcissina declined along C course. This species was mainly recorded at patches of deciduous trees in coniferous forest in 1983. There are two possibilities for the decline of this species; the habitat change because of tree falls around the forest trails, and the fluctuation/decline of the number of migratory population in this area. Hirano, T. 1997. The effect of riverbank repairworks on wintering water bird populations. Strix 15: 39-44. 1. A bird census was conducted in the winters of 1992 and 1993, along the Tagawa River in Utsunomiya, central Honshu, in order to determine how the repairworks had affected the populations and the number of species. 2. There were no significant changes in populations on the Tagawa River in Yaitamachi where no habitat changes had been caused. 3. The river repairworks were carried out from 1987 to 1992 in Iwazomachi. The river was broadened and the banks were covered with concrete, resulting in severely depleted vegetation. 4. In 1982 and 1986 before the repairworks there were six and eight species with mean totals of 9.25 and 10.33 individuals. In 1992 and 1993 after the works, however, both species number and mean total increased. The former was 8 and 9, and the latter was 21.25 and 22.25. 5. Long-billed Ringed Plovers Charadrius placidus, Common Sandpipers Tringa hypoleucos, Green Sandpipers Tringa ochropus, White Wagtails Motacilla alba and Japanese Wagtails Motacilla grandis increased in number after the repairworks. This increase seemed to be due to the increase of gravel areas. The original gravel area of one a increased to 50 a. 6. Little Grebes Podiceps ruficollis, Teals Anas crecca, Grey Wagtails Motacilla cinerea and Brown Dippers Cinclus pallasii disappeared or decreased in number. The disappearance of Little Grebes and Teals was probably associated with the removal of the river bank vegetation which had prevented human access. However, the reasons for the disappearance of Brown Dippers and the decrease of Grey Wagtails are not clear. Kawashima, K. 1997. Fluctuations of wader populations in relation to the construction of the Tokyo Port Wild Bird Park. Strix 15: 45-53. A population study of waders was conducted in Ooi Estuary in Tokyo Bay. The comparison of the populations was made before and after Tokyo Port Wild Bird Park was constructed with the purpose of preserving the estuarine habitat of the Ooi reclaimed land. The Ooi Estuary area originally had fresh water areas, brackish ponds, tidal flat, grassland, gravel areas and so on. The study was made from 1976 to 1979 and from 1991 to 1995, before and after the construction of the park. The count was made in spring and autumn when most of the waders were visiting. The numbers of most visiting waders had increased in the later spring counts. However, Little Ringed Plovers Charadrius dubius and Snowy Plovers, C. alexandrinus declined drastically after the park construction. The numbers of species and of individuals decreased in autumn, with a marked decline of Snowy Plovers and Wood Sandpipers Tringa glareola, in particular. The number of Black-winged Stints Himantopus himantopus increased in spring and autumn after the construction of the park. It is suggested that the decrease in the area of the tidal flat caused the decrease in the number of species and individuals and that the decrease of the Little Ringed and the Snowy Plover was caused by decrease in the gravel area which is their main breeding site. We conclude that it is necessary to increase the tidal flat area and to create both gravel and fresh water marsh areas in order to create the habitat with the same diversity as the previous tidal flat. Fujimaki, Y. 1997. Distribution and abundance of the Japanese Grosbeak and the Hawfinch in central and south-eastern Hokkaido. Strix 15: 55-62. The populations of the Japanese Grosbeak Eophona personata and the Hawfinch Coccothraustes coccothraustes were censused along one or two 2-km transects (a total of 401) situated in 358 quadrats (5 x 5 km) in central and south-eastern Hokkaido from late April to late July, 1976-1996. Japanese Grosbeaks occurred mainly in forested areas below 700 m above sea level and Hawfinches in agricultural and residential areas below 700 m above sea level in addition to forested areas. The distributions of the two species did not overlap except in forested areas. Of 358 transects in which the censuses were carried out, Japanese Grosbeaks were observed in 54% of deciduous broad-leaved forests, 44% of larch plantations, 35% of agricultural areas with woods, 25% of evergreen coniferous forests and 23% of mixed forests. Hawfinches were observed in 66% of agricultural areas with woods, 57% of residential areas, 56% of larch plantations, and 42% of agricultural areas. The number of birds (mean ± SD) counted per 2-km transect was 0.8±1.6 in deciduous broad-leaved forests, 0.4±0.6 in larch plantations, 0.2±0.5 to 0.1±0.4 in evergreen-coniferous and mixed forests and agricultural areas with woods, and less than 0.1 in agricultural and residential areas for Japanese Grosbeaks. The corresponding values for Hawfinches were 1.2±1.4 in residential areas, 1.0±1.1 in agricultural areas with woods, 0.6±0.9 in deciduous broad-leaved forests, 0.5±0.7 in larch plantations and agricultural areas, 0.3±0.4 in evergreen-coniferous forests and 0.3±0.7 in mixed forests. The Hawfinch preferred relatively open habitats more than the Japanese Grosbeak did. Morita, M., Y. Kanai, M. Ueta, M. Narusue, M. Koita, & K. Kaji. 1997. Relation between benthos and shorebirds in Tokyo Bay tidal flats. Strix 15: 63-68. We studied the relationship between food abundance and the density of shorebirds. We assessed abundance of benthos in six Tokyo Bay tidal flats from mid-August to late September 1995. The density of benthos inhabiting mudflats was significantly higher than that in the sandflats. There was no significant correlation between the number of species of shorebirds and the total amount of benthos as estimated from samples of its density at each tidal area. Correlation between the densities of each of six shorebird species observed at study sites and that of benthos was not significant. It seems that numbers of shorebirds are related to other factors, such as resting sites at high tide, and not solely upon benthos density. Ueta, M., & Y. Yamaguchi. 1997. Habitat preferences of Lidth's Jays, White-backed Woodpeckers, and Japanese Wood Pigeons in Amami Island, southern Japan. Strix 15: 69-74. The habitat preference of the Lidth's Jay Garrulus lidthi, White-backed Woodpeckers Dendrocopos leucotos owstoni, and Japanese Wood Pigeons Columba janthina were studied on Amami Island in January 1995. We classified vegetation into four types based on dominant plants: 1. mature evergreen forest (dominant trees of DBH larger than 30 cm), 2. Immature evergreen forest (dominant trees of DBH smaller than 30 cm), 3. pine tree plantation, and 4. deforested open areas. We observed the birds, and recorded the time they spent in each vegetation category. All three species significantly preferred mature forest, which accounted for 93.0 % of 764 min. observation time of Lidth's Jay, 93.9 % of 115 min of observation of White-backed Woodpecker and 93.9 % of 164 min. of observation of Japanese Wood Pigeon. This result shows that the mature evergreen forest is important for the conservation of these bird species. Morita, M. 1997. Habitat structure of Red-crowned Cranes in eastern Hokkaido. Strix 15: 75-81. I studied the habitat structure of four home ranges established by pairs of Red-crowned Cranes Grus japonensis during the breeding period, from late April to early August of 1993, in eastern Hokkaido. Occurence rate of six environmental factors within a radius of one kilometer of the crane nests were compared with the actual use by the cranes. The cranes used wetlands, swamps and rivers more frequently than expected from the proportion of each environmental factor. The Ivlev's selective coefficient (Ivlev 1955) about rivers and swamps showed positive. On the other hand, the coefficient about artifacts and forests were negative. The difficulty of observation of cranes in closed forest made the coefficient in forests negative. The home range expanded gradually with the growth of chicks. The ranges of a pair which were unsuccessful in breeding were larger than those of pairs with chicks. Shimada, T., & K. Kuwabara. 1997. The distributions of Greater Scaup and of Pochard at the mouth of the Yoro River. Strix 15: 83-88. The distributions of Greater Scaup Aythya marila and Pochard A. ferina in the estuary of the Yoro River in central Japan were investigated during November 1991 - December 1992. The estuary of the Yoro River was divided into 8 meshes, which were classified into three areas (Sea, Lower River Mouth and Upper River Mouth). Both species were resting in the study area. In the Sea, the density of Greater Scaups (121.0 / km2) was significantly higher than that of Pochards (37.9 / km2). At the Lower River Mouth, the density of Pochards (346.8 / km2) was significantly higher than that of Greater Scaups (85.9 / km2). In the Upper River Mouth neither species occurred. The factors determining the distributions of both species are discussed. Igarashi, H. 1997. The roosting behavior of Night Herons in winter. Strix 15: 89-94. The roosting behavior of Night Herons Nycticorax nycticorax was investigated at their winter roosts on Tokyo from December 1992 to April 1993 and September 1994 to February 1995. Night Herons back to their roost on morning. The time when herons arrived at the roost sites ranged between 48 min before sunrise and 54 min after sunrise, while most herons arrived at the roost sites from 30 min to 20 min before sunrise, and 94.1% of the roosting herons arrived before sunrise. There was a significantly high correlation between arrival time and sunrise. Light intensity, therefore, seems to be one of the most important factors affecting their arrival at the roosts. Narusue, M., M. Fukuda, K. Fukui, & Y. Kanai. 1997. Changes in the distribution of breeding colonies of Common Cormorants in the Kanto District. Strix 15: 95-108. We studied changes in the distribution of breeding colonies of Common Cormorants Phalacrocorax carbo in the Kanto District by literature and personal communication, from 1920s to March in 1995. We also conducted observation of distribution of the cormorants from March, 1994 to March, 1995 in the Kanto District. During the eight decades, there were seven sites where cormorants bred and five sites where they built nests but hardly bred. During each decade from 1920s to 1960s there were only two breeding colonies. Cormorant populations decreased until the early 1970s due to deteriorating breeding habitat, hunting, reclamation along Tokyo Bay and degrading water quality of the Bay, which was the foraging area of the species. After that, however, the population has gradually increased because of the breeding colony secured in Shinobazu Pond in Ueno and the improvement of water quality in Tokyo Bay. Four breeding colonies of cormorants were located in the Kanto District from March in 1994 to March in 1995. It is considered that the distribution of cormorants is greatly influenced by human behavior towards them. Kobayashi, Y., Y. Yamamoto, & J. T. Moyer. 1997. Status of Japanese Murrelets Synthliboramphus wumizusume at Oonohara-jima, Miyake-jima, central Japan. Strix 15: 109-115. 1. From April to May, 1995, we censused from fishing boats the population of Japanese Murrelets Synthliboramphus wumizusume which breeds at Oonohara-jima, Miyake-jima, central Japan. 2. During the five surveys, the birds were mainly observed in the region of Oonohara-jima. We counted 205 birds, including a maximum of two chicks on 11 May, and a minimum of nine birds were observed on 25 May. 3. We investigated the breeding site of Japanese Murrelets on 1 May 1995 at Koyasu-ne of Oonohara-jima. Three nests were discovered. Each nest contained a single egg, but two of the eggs were punctured and destroyed, and 27 dead adults were found in the breeding site. 4. The breasts and abdomens of the dead adults were eaten by predators. The predators were not identified, but we observed Jungle Crows Corvus macrorhynchos and Peregrine Falcons Falco peregrinus in the breeding site. It is probable that these predators preyed upon the Japanese Murrelets. Suzuki, Y., Yui, M. & Sakuyama, M. 1993. Forest bird community of Tobishima Island. Strix 12: 139-144. (In Japanese with English summary) Forest bird communities of Tobishima Island in Yamagata Prefecture were studied by line-transect census method from 1991 to 1993. The Island is 28km away from Honshu, and is covered with pine trees. In the breeding season of eachyear, we found 16 terrestrial bird species. Dominant species in the breeding season were Brown-eared Bulbuls Hypsipetes amaurotis, Japanese White-eyes Zosterops japonicus, Great Tits Parus major, Oriental Greenfinches Carduelis sinica and Japanese Bush Warblers Cettia diphone. The dominant species in winterwere Coal Tits Parus ater, Great Tits Parus major and Carrion Crows Corvus corone. Amami Ornithologists' Club. 1997. A population estimate of the endangered Amami Thrush made by counting singing birds. Strix 15: 117-121. The Amami Thrush is believed to be a distinct species which is endangered, and is endemic to the single small island of Amami in southern Japan. It inhabits mature evergreen forest. The population is quite small and fragmented. We estimated the population size by counting the singing birds in spring 1996. The number recorded this year was 29, and the whole breeding population maybe a little larger than 58 birds (= 29 x 2). The population in the main habitat is thought to have decreased in recent years, probably owing to clear cutting of naural forest good for the species. The species is "endangered" and probably "critically endangered" according to the IUCN's new categories. Ueda, K., & M. Karaki. 1997. Nectar robbing from flowers of the introduced Bryophyllum pinnatum (Crassulaceae) by Japanese White-eyes. Strix 15: 122-126. We observed nectar robbing by the Japanese White-eye Zosterops japonica from the introduced Bryophyllum pinnatum (Lam.) Kurz flowers. We surveyed Bryophyllum flowers pierced by the White-eyes at 21 localities on Chichijima Is. and Hahajima Is. of the Bonin Islands in May, 1991. We checked 1655 flowers on Chichijima Is. and 3268 on Hahajima Is. Of flowers checked, 67.6 % on Hahajima and 37.4 % on Chichijima were pierced by White-eyes; this difference was significant. Nectar robbing is a parasitic relationship between birds and flowers which has not been previously observed in the Bonin Islands. Takagi, M., & M. Takahashi. 1997. Three Passerine birds bred in the nests of Black Kites. Strix 15: 127-129. We observed that nine pairs of Tree Sparrows Passer montanus, a pair of Russet Sparrows P. rutilans, and a pair of White Wagtails Motacilla alba bred in the nests of Black Kites Milvus migrans in Ishikari, Hokkaido, on May 25-29, 1996. These small birds selected the active nests of the kites for their own nesting sites. It suggested that those small birds would exploit the defensive ability of the kites to avoid nest predation. Inouye, K. 1997. The migration of Grey-faced Buzzard-Eagles in spring in northwestern Kyushu. Strix 15: 130-132. I observed the migration of Grey-faced Buzzard-Eagles Butastur indicus from early April to early May, in 1994 and 1995 in northwestern Kyushu. I observed a total of 53 Grey-faced Buzzard Eagles migrating eastwards during 3 days at the Sefuriyama Mountains. However, 6 Grey-faced Buzzard Eagles were observed migrating southwards during 12 days at Mt. Kinpou, which suggests that there is another migration route for Grey-faced Buzzard-Eagles in northwestern Kyushu. Ueta, M., K. Nippashi, & H. Higuchi. 1997. Effect of transmitters on the behavior of wild and captive Whooper Swans. Strix 15: 133-137. We studied the effect of transmitters on the behavior of eight wild and two captive Whooper Swans Cygnus cygnus, based on their pecking time of the transmitters. The transmitters, 60 x 40 x 30 mm in size, was attached to the back of swans with teflon treated ribbon. The transmitter with its harness weighed about 85g, which is less than 1% of the body weight of an adult swan. The swans pecked their transmitters more than 100 seconds per 15 minutes on the first day of attachment. The pecking time decreased rapidly to only 3.2 to 22.8 seconds / 15 minutes in two days. We concluded that the transmitters did not have any significant effect on the swans’ behavior. Daimon, H. 1997. A record of Black-faced Spoonbill display behavior in Ishikawa Prefecture. Strix 15: 138-140. 1. In the mouth of the Kawashiri River in Taturuhama Town, Kashima District, Ishikawa Prefecture, one adult Black-faced Spoonbill Platalea minor in breeding plumage was observed on May 8 1996. 2. One adult Black-faced Spoonbill in breeding plumage, and one juvenile Black-faced Spoonbill were observed in the mouth of the Kawashiri River on June 24. 3. Three Black-faced Spoonbills were observed in the mouth of the Kawashiri River on June 25. Judging from their body sizes, the adult Black-faced Spoonbills observed on May 8 and June 24 were male and female respectively. 4. Male and female Black-faced Spoonbills were not observed except in the evening from June 27 on, because they went into a heronry during the day. Display behaviour was also observed. 5. On July 15, three Black-faced Spoonbills were observed at the same time. The male and female Black-faced Spoonbills did not go into the heronry. On July 26, the female and the juvenile Black-faced Spoonbill were not observed. Yahagi, E. 1993. Frequency of nest box use by Tits Paridae in Hakone. Strix 12: 193-199. (In Japanese with English summary) The use of nest boxes for breeding was studied using about 50 nest boxes from 1976 to 1988 at Hakone Arboretum, a woodland of 12 ha in Hakone district, Kanagawa. The percentage of available nest boxes used by Tits PARIDAE was 54.7％(361/660). Species using 357 nest boxes were identified: (129 were Varied Tits Parus varius, 224 were Great Tits P. major, and only four were Coal Tits P. ater). The nest boxes placed at near the forest edge were used more freguently than those in the central part, particularly by Varied Tits. Varied Tits also tended to use nest boxes placed in broad-leaved decidous trees, while Great Tits more frequently used boxes placed in ever-green coniferous trees and in areas of widely scattered trees. Yahagi, E. 1997. Movements of a family flock of Great Tits Parus major in Hakone, central Japan. Strix 15: 141-143. The movements of marked adults and nestlings of Great Tits were studied from 1975 to 1988 in the Hakone Arboretum, a woodland of 12 ha. One family flock, consisting of a female and three young, which were thought have left their nest at Hakone Arboretum on July 18, was observed at Onshi-Hakone Park, 3.8km from the Arboretum, on August 4, 1976. Matsuda, M. 1997. Feeding of Great Tit chicks by Long-tailed Tits. Strix 15: 144-147. I observed four Long-tailed Tits Aegithalos caudatus bringing food to a Great Tit's Parus major nest in a resort-cottage area of Tokorono, Nikko-city, Tochigi Prefecture. The observations were made on 5, 6, and 11 of June 1996. This is the fifth time that interspecific feeding behavior has been observed in Japan.