Mutsuyuki Ueta

Migration routes and important resting areas of Siberian cranes (Grus leucogeranus) between northeastern Siberia and China as revealed by satellite tracking

In 1995 and 1996 thirteen Siberian cranes (Grus leucogeranus) were fitted with satellite transmitters on the breeding grounds in northeastern Siberia. Eleven of these 13 birds were successfully satellite tracked, and five of these 11 provided complete migratory information from their breeding grounds in Yakutia, Siberia, to their wintering area at Poyang Lake, in China. Several stopover sites were identified, the most important being in Qiqihar-Baicheng (China), Shuangtaizi River delta (China), and Yellow River delta (China). Birds rested more frequently in Russia than in China, suggesting availability of suitable wetland habitat in Russia and absence of adequate, suitable wetland habitat in China. Wintering habitat in China also faces numerous threats. Habitats utilized by Siberian cranes are also important to other threatened wetland birds that have been satellite-tracked recently. If Siberian crane habitat needs fail to be addressed, this critically endangered species will be further endangered.

Satellite tracking of the migration of the red‐crowned crane Grus japonensis

Autumn migration routes of red-crowned cranes, Grus japonensis, from two continental east Asian sites were documented in detail by satellite tracking. Two routes were identified: a 2200 km western route from Russia’s Khingansky Nature Reserve to coastal Jiangsu Province, China; and a 900 km eastern route from Lake Khanka (Russia) to the Korean Peninsula and the Demilitarized Zone. The most important rest-sites were identified as Panjin Marsh (China), coastal mudflats south-east of Tangshan City (China), the Yellow River mouth (China), Tumen River mouth (North Korea/China/Russia), Kumya (North Korea) and Cholwon (Korean DMZ). Movements within the wintering range were also recorded, including complex commuting between sites by individual cranes and patterns of daily movements within sites. These data should prove useful for conservation of the flyway.

Spring Migration Routes of Mallards (Anas platyrhynchos) that Winter in Japan, Determined from Satellite Telemetry

Abstract Wild birds, in particular waterfowl, are common reservoirs of low pathogenic avian influenza viruses, and infected individuals could spread the viruses during migrations. We used satellite telemetry to track the spring migration of the mallard ducks (Anas platyrhynchos) that winter in Japan. We studied their migration routes, distribution of stopover and breeding sites, and timing of migration movements. We tracked 23 mallards from four different wintering sites. Nine of the 23 mallards reached presumable breeding sites, where migration terminated. The migration routes of the birds greatly differed not only among the wintering sites but also within the same wintering site, although the general feature of the routes was shared among birds within the same wintering site. The mallards used several stopover sites, and they typically stayed for a long period (about one to four weeks) at a site between migration intervals of two to three days. Stopover sites were located in northeast Japan, the eastern coastline of South Korea and North Korea, and the interior of Far Eastern Russia. Mallards from three different wintering sites used a stopover area near the middle part of the Ussuri river in Russia. The terminal sites, which were presumably also breeding sites, were distributed widely over northeast Asia and Far Eastern Russia. These results suggest that mallards that winter in Japan originate from breeding areas widely distributed across eastern Asia. Mallards could potentially transmit avian influenza viruses between Japan and a broad region of northeastern Asia.

Azure-winged magpies, Cyanopica cyana, parasitize nest defence provided by japanese lesser sparrowhawks, Accipiter gularis

Abstract Abstract. A field experiment with simulated nests of azure-winged magpies was carried out to test the hypothesis that this species nests in association with Japanese lesser sparrowhawks in order to reduce nest predation while paying few costs. The predation rate on nests was lower within 50 m of a hawks nest during the incubation to nestling period than it was further away or at other stages of the breeding cycle. In addition, there was an inverse relationship between nest predation rate and hawk defence effort. Observations of natural nests showed that magpies did not defend their nests when nesting close to a hawk, and that hawks rarely preyed on magpies. Thus, magpies benefited from nesting close to hawks, while paying few or no costs.

Difference in Migration Pattern Between Adult and Immature Birds Using Satellites

Abstract We satellite-tracked Stellers Sea Eagles (Haliaeetus pelagicus), Black-faced Spoonbills (Platalea minor), and White-naped Cranes (Grus vipio) to determine migration routes and stopover tactics of adult and immature birds. During spring migration, there were no significant differences between adult and immature birds in total migration distance and distance between stopover sites, but the migration period and resting period at stopover sites were significantly longer in immature individuals. There are two possible tactics for migrating without expending fat stores: longer rests or shorter migration distances between stopover sites. Our results suggest that immature birds try to increase fat stores by increasing time available for foraging at stopover sites.

Discovery of breeding grounds of a Siberian Crane Grus leucogeranus flock that winters in Iran, via satellite telemetry

Summary Siberian Crane Grus leucogeranus occurs only in Asia, and is Critically Endangered. The western population of the species has been almost extirpated, wintering at just two known sites, in Iran and India. To help conserve species that migrate long distances it is essential to have a comprehensive conservation plan that includes identification of migration routes and key resting areas. One Siberian Crane was satellite-tracked from the south Caspian Sea to its breeding grounds in Russia during the spring of 1996. The crane began migration on 6 March, and completed its migration on 1 May. This destination was formerly unknown as a breeding area for the species. During migration, the crane rested primarily at the eastern end of the Volga River delta. This suggests that the delta may be an important resting site for Siberian Crane.

Seasonal change in habitat use in Steller's sea eagles

Habitat-use by Stellers sea eagle Haliaeetus pelagicus , categorized as Vulnerable on the 2002 IUCN Red List, was studied using satellite-tracking. This migratory species breeds in eastern Russia and mostly overwinters in Hokkaido, Japan, and the southern Kuzil islands. Locations of eagles were classified as being river, sea, lake, or other habitat. In autumn, eagles mainly used river habitats, probably because of the availability of abundant post-spawn dead salmon. In winter about one third of eagles continued to be located on rivers, with others on sea coasts and lake sides. During the spring migration and breeding season habitat use by adult eagles probably reflected the variety of habitats in which breeding occurs. At that time, sub-adult eagles were located mainly on the sea coast, probably in places where food supply was sufficient and there were few territorial eagles. In Hokkaido 35% of overwintering eagles used mountain areas for at least some time. It is known that eagles using mountain areas in Japan in winter scavenge upon the carcasses of sika deer Cervus nippon killed by hunters, and are thus exposed to possible lead poisoning. The satellite tracking highlights the importance of several habitats within the range of this species, changes in which could affect its conservation status.

Correction of elevation-induced errors in locations of the ARGOS satellite-tracking system

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. Satellite tracking data has been useful for conservation of several bird species, and therefore accurate location data are required for such work. The ARGOS satellite-tracking system requires that the elevation of a platform transmitter terminal (PTT) be estimated before a location is calculated. Extreme errors can occur if the estimated elevation is incorrect. The authors have developed two correction methods for elevation induced errors that use the estimated locations on the assumption of zero-meter elevation. First, they attached an atmospheric pressure sensor to the PTT. The true elevation of the PTT can be calculated from the atmospheric pressure data transmitted via the satellite of the ARGOS system. The elevation-induced errors can be corrected by the geometrical calculations using the data of the estimated location, spurious location, assumed elevation (0 m) and true elevation. Second, they use a global digital elevation model (DEM) GTOPO30 with a horizontal grid spacing of 30 are seconds that is offered by USGS (U. S. Geological Survey). The elevation of PTT is estimated at the location reported from the ARGOS system by use of DEM. The elevation-induced errors are reduced by the same calculation as the first method. Next, the elevation of PTT is estimated at the corrected location. Iterating these calculations, the true elevation and location can be calculated.