ИСТИНА

Seasonal migrations are an essential part of the annual routine in most songbird species that breed in temperate and northern latitudes. Information on migration connectivity in songbirds is crucial for understanding of their ecology and evolution, as well as the effective conservation and forecasting the spread of diseases. Bird banding has provide the principal technique to study songbird migration. Despite over a century of bid banding, relatively little information has been garnered on linkages between breeding, stop-over and wintering sites for many species, even where extensive effort has occurred along the flyway. The collection of sufficient population specific information about wintering ground connectivity from bird banding in the Asia-Pacific Region is questionable. We therefore applied analysis of stable-hydrogen isotope ratios of claw keratin in bird as an alternative to banding in order to depict wintering grounds of Siberian Rubythroat (Luscinia calliope) from the central Amurland (n=22) and South of Sakhalin Island (n=18) using δ2H from the distal end of bird claws, captured at stopovers soon after their arrival from wintering grounds. Values of δ2H indicated two large spatial clusters where Rubythroats from Amurland and Sakhalin most likely over-wintered: one on the mainland from the Western Bengali in India through eastern Myanmar, another one is likely the Philippine Islands. This result suggests a possible migration divide between Amurland and Sakhalin birds. However this spatial assignment could not separate these two possible wintering grounds since the two regions are predicted to be isotopically similar based upon δ2H isoscapes. We will also analyze additional samples from the winter grounds in Thailand in order to validate migration links of species under study. Preliminary results suggest that the isotopic method may provide a useful addition to traditional band recovery efforts along the East Asian Flyway.