Are there two species of Short-tailed Albatross?
I have now a copy of this interesting paper.
The authors have analysed the DNA (plus stable isotope ratios) of 1000 year-old bones of Short-tailed Albatross, finding two distinct clades, suggesting the ‘Short-tailed Albatross’ existed in two distinct populations. The genetic distance between them though was found to be greater than that of other sister albatross species. The authors suggest that birds at the present two breeding sites are descended from these two ancient populations, and that a re-evaluation of the status and conservation strategy for the species is required.
It was known that very few of these albatrosses survived the slaughter for their feathers, and that by the mid 20th century only some 50 birds in total were left (all believed at Torishima), but the article now puts forward that a very small population were overlooked, on the Senkaku Islands. So, descendants of each population seem to have survived at both locations. There is no evidence of any emigration from Torishima to the Senkaku Islands which now has some 500 birds (a correction from my previous post) - for example, nearly all Torishima birds have been fitted with metal leg bands as chicks since 1979, and no banded birds have been observed on the Senkaku Islands, in various years of the 1980’s, 1990’s, 2001/2. Unfortunately, no surveys can take place at the present time due to territorial disputes between China, Taiwan and Japan.
The sequence diversion between these two clades, two populations, is an amazing 11.5%. Consider, for example, 2.9% between Salvin’s and Chatham Albatrosses, or 7.2% between Black-browed and Campbell Albatrosses.
The authors do not introduce ‘the species argument’ but, on the above, there does seem to be a case for splitting the Short-tailed Albatross; the Torishima and Senkaku birds. More work is needed on the Senkaku birds (on the islands and within the museum collections) as I do not think any study has yet been made on further morphology of the two, so this may be yet another cryptic species.