2011 Volume 43 Issue 1 Pages 57-64
The Short-tailed Albatross Diomedea albatrus is a vulnerable seabird that breeds on Torishima, one of the Izu Islands, and on Minami- and Kita-kojima islands in the Senkaku Islands. An unringed bird has been observed at the Hatsunezaki colony on Torishima every year since 1996, even though since 1979 almost all birds hatched on Torishima have been ringed on both legs. This unringed individual was named Deko-chan as, until the 2005/06 breeding season, it made a nest every year near a decoy that was set to attract the birds to Hatsunezaki. Given that losing the rings from both legs while still having sub-adult plumage is unlikely, the natal site of the bird was suspected to be the Senkaku Islands. The identification of Deko-chan's natal site is important to assess whether birds from the Senkaku Islands are coming to Torishima and whether birds from the two islands are pairing. Our previous studies using control region 2 (CR2) of the mitochondrial DNA sequence suggested that the species includes two distinct populations (clades 1 and 2), with birds breeding on Torishima mostly consisting of descendants of clade 1 individuals, and those sampled in the Senkaku Islands comprised of descendants of clade 2 individuals. In this study, we analysed CR2 obtained from down collected from the nest of Deko-chan. The results reveal that Deko-chan has a CR2 sequence that differs from any reported to date, but indicates that it belongs to clade 2, supporting the suggestion that the natal site of the bird is the Senkaku Islands, not Torishima. Although the bird had paired with a ringed bird and reared two young by the 2009/10 breeding season, further studies using bisexually transmitted molecular markers are required to confirm whether the two lineages are able to mix.
