Are there two species of the 'Short-tailed Albatross'?
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Tony Pym
Oct 6, 2011, 6:00:46 PM10/6/11
to Seabird News
In the most recent issue of the journal 'Conservation Genetics' there
is a very interesting paper ('Inferring the ancient population
structure of the vulnerable albatross Phoebastria albatrus, combining
ancient DNA, stable isotope, and morphometric analyses of
archaeological samples’: Eda et al)
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 their
slaughter for the feather trade, 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 - 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 study years of the
1980’s, 1990’s, 2001/2. It is unfortunate that 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 a possible future split of the Short-tailed Albatross
- the Torishima and Senkaku birds – though, it might be said, more
work is needed on the Senkaku birds (both, on the islands whenever
possible, and within the museum collections) to prove with certainty
that members of this relict population do have the lineage, and to
check further the morphology as this may be yet another cryptic
species.
is a very interesting paper ('Inferring the ancient population
structure of the vulnerable albatross Phoebastria albatrus, combining
ancient DNA, stable isotope, and morphometric analyses of
archaeological samples’: Eda et al)
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 their
slaughter for the feather trade, 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 - 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 study years of the
1980’s, 1990’s, 2001/2. It is unfortunate that 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 a possible future split of the Short-tailed Albatross
- the Torishima and Senkaku birds – though, it might be said, more
work is needed on the Senkaku birds (both, on the islands whenever
possible, and within the museum collections) to prove with certainty
that members of this relict population do have the lineage, and to
check further the morphology as this may be yet another cryptic
species.
Angus Wilson
Oct 6, 2011, 6:51:06 PM10/6/11
to Seabird News
Hi Tony, Very interesting. Not having access the paper, can I ask a few basic questions.
1. Is the DNA and isotope work based on the sub-fossils or on living birds as well? In other words, if there were two taxa is there any firm evidence both are still extant?
2. Are there any behavioral (or non-molecular) clues beyond the lack of mixing to suggest the two island populations are distinct in any way? Have there been hints at differences before?
3. Is the degree of divergence reported comparable to other cryptic species pairs? The percentages seems high considering the examples you give but I have absolutely no feel for this.
4. Is is known or assumed that the Short-tailed Albatross nesting on Midway come from the Torishima population?
Obviously there are significant conservation issues if this pans out. The upside of the intense territorial dispute over the Senkaku islands is it might mean the albatross are left alone. Am I right that an unspoken reason for the quarrel (at least between PRC and ROC is the potential for exploitable 'seabed resources' in the area?
Cheers, Angus Wilson
1. Is the DNA and isotope work based on the sub-fossils or on living birds as well? In other words, if there were two taxa is there any firm evidence both are still extant?
2. Are there any behavioral (or non-molecular) clues beyond the lack of mixing to suggest the two island populations are distinct in any way? Have there been hints at differences before?
3. Is the degree of divergence reported comparable to other cryptic species pairs? The percentages seems high considering the examples you give but I have absolutely no feel for this.
4. Is is known or assumed that the Short-tailed Albatross nesting on Midway come from the Torishima population?
Obviously there are significant conservation issues if this pans out. The upside of the intense territorial dispute over the Senkaku islands is it might mean the albatross are left alone. Am I right that an unspoken reason for the quarrel (at least between PRC and ROC is the potential for exploitable 'seabed resources' in the area?
Cheers, Angus Wilson
Alex Bond
Oct 6, 2011, 7:46:29 PM10/6/11
to Seabird News
Hi all,
The data are from subfossil bones dating from 700-1200 CE from adults, immatures, and birds of unknown age.
As someone who works extensively with isotopes in seabirds, and having read the paper, I have serious concerns about the interpretation of isotopic data as presented (although it doesn't lend much to the overall "story" of the paper, which is genetic, and largely beyond my expertise).
Regards,
Alex Bond
Saskatoon, Saskatchewan, Canada
The data are from subfossil bones dating from 700-1200 CE from adults, immatures, and birds of unknown age.
As someone who works extensively with isotopes in seabirds, and having read the paper, I have serious concerns about the interpretation of isotopic data as presented (although it doesn't lend much to the overall "story" of the paper, which is genetic, and largely beyond my expertise).
Regards,
Alex Bond
Saskatoon, Saskatchewan, Canada
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Tony Pym
Oct 7, 2011, 9:00:57 AM10/7/11
to Seabird News
Hi Angus
Apologies for this long reply!
On Oct 6, 11:51 pm, Angus Wilson <oceanwander...@gmail.com> wrote:
> Hi Tony, Very interesting. Not having access the paper, can I ask a few
> basic questions.
>
> 1. Is the DNA and isotope work based on the sub-fossils or on living birds
> as well? In other words, if there were two taxa is there any firm evidence
> both are still extant?
>
(a) As Alex says this particular study paper was on subfossil bones
predominantly, all some 1000 yrs old. They say also, that 45 ‘modern’
samples (41 from Torishima and four from the Senkaku Islands) were
analyzed, though these are not dated (and similar levels of diversity
were found for both the ancient and modern samples). The main authors
have written two other papers on mtDNA analysis with modern Short-
tailed Albatrosses. I do not have these at present but I’m underway
trying to retrieve the most important. I do know that two clades were
found in this earlier study also, one specific to Torishima and the
other spread over both regions.
(b) There is belief, as none of the Senkaku population carry leg bands
and over a thirty-year period of looking, they have not originated
from Torishima.
> 2. Are there any behavioral (or non-molecular) clues beyond the lack of
> mixing to suggest the two island populations are distinct in any way? Have
> there been hints at differences before?
>
(a) Hasegawa (guru and saviour of the species) noted different
courtship displays (pre-mating isolation) and different breeding
seasons (by a few weeks). Also, he noted some retarded chicks on
Torishima in the 90’s – notably in the same area of the colony – these
may have had genetic problems (inter-breeding?)
(b) I don’t think there has even been the suggestion of sub-species
status for the Senkaku birds in the past. Checking back on early
references, the earlier names proposed (scientific synonyms) do not
appear to make any direct link to the Senkaku Islands.
> 3. Is the degree of divergence reported comparable to other cryptic species
> pairs? The percentages seems high considering the examples you give but I
> have absolutely no feel for this.
>
I’m surprised also at the high sequence diversion (11.5%). The large
albatrosses have been debated the most over the years, with various
percentage variations quoted, then questioned, by different authors.
Examples, raised the most in conversation I suppose, would be the
Wandering complex and Shy complex where species/races and close
similarity are passionately tackled. Further examples of percent
divergence in sister taxa – Gibson’s and Antipodean Albatross 1%,
(Tasmanian) Shy and White-capped 1.8%, Wanderer (Snowy) and Tristan
4.5%. As for storm-petrels, Monteiro’s as an example, I recall a
figure of 1.5-2%, so this figure for Short-tailed Albatross is
impressive. For larger species (e.g. albatrosses) for each percent the
evolutionary timescale is said to be longer and, some taxonomists have
questioned timescales/DNA variation with the storm petrels also.
> 4. Is is known or assumed that the Short-tailed Albatross nesting on Midway
> come from the Torishima population?
>
Certain, both parents were hatched and banded on Torishima.
> Obviously there are significant conservation issues if this pans out. The
> upside of the intense territorial dispute over the Senkaku islands is it
> might mean the albatross are left alone. Am I right that an unspoken reason
> for the quarrel (at least between PRC and ROC is the potential for
> exploitable 'seabed resources' in the area?
>
I’m not clued-up on this, and it’s complicated (historic problems
between China and Japan, made worse with island claims after WW2).
To end on a high note, the Short-tailed Albatross population have
grown well – the population now estimated at 3000 birds.
Regards
Tony
Apologies for this long reply!
On Oct 6, 11:51 pm, Angus Wilson <oceanwander...@gmail.com> wrote:
> Hi Tony, Very interesting. Not having access the paper, can I ask a few
> basic questions.
>
> 1. Is the DNA and isotope work based on the sub-fossils or on living birds
> as well? In other words, if there were two taxa is there any firm evidence
> both are still extant?
>
predominantly, all some 1000 yrs old. They say also, that 45 ‘modern’
samples (41 from Torishima and four from the Senkaku Islands) were
analyzed, though these are not dated (and similar levels of diversity
were found for both the ancient and modern samples). The main authors
have written two other papers on mtDNA analysis with modern Short-
tailed Albatrosses. I do not have these at present but I’m underway
trying to retrieve the most important. I do know that two clades were
found in this earlier study also, one specific to Torishima and the
other spread over both regions.
(b) There is belief, as none of the Senkaku population carry leg bands
and over a thirty-year period of looking, they have not originated
from Torishima.
> 2. Are there any behavioral (or non-molecular) clues beyond the lack of
> mixing to suggest the two island populations are distinct in any way? Have
> there been hints at differences before?
>
courtship displays (pre-mating isolation) and different breeding
seasons (by a few weeks). Also, he noted some retarded chicks on
Torishima in the 90’s – notably in the same area of the colony – these
may have had genetic problems (inter-breeding?)
(b) I don’t think there has even been the suggestion of sub-species
status for the Senkaku birds in the past. Checking back on early
references, the earlier names proposed (scientific synonyms) do not
appear to make any direct link to the Senkaku Islands.
> 3. Is the degree of divergence reported comparable to other cryptic species
> pairs? The percentages seems high considering the examples you give but I
> have absolutely no feel for this.
>
albatrosses have been debated the most over the years, with various
percentage variations quoted, then questioned, by different authors.
Examples, raised the most in conversation I suppose, would be the
Wandering complex and Shy complex where species/races and close
similarity are passionately tackled. Further examples of percent
divergence in sister taxa – Gibson’s and Antipodean Albatross 1%,
(Tasmanian) Shy and White-capped 1.8%, Wanderer (Snowy) and Tristan
4.5%. As for storm-petrels, Monteiro’s as an example, I recall a
figure of 1.5-2%, so this figure for Short-tailed Albatross is
impressive. For larger species (e.g. albatrosses) for each percent the
evolutionary timescale is said to be longer and, some taxonomists have
questioned timescales/DNA variation with the storm petrels also.
> 4. Is is known or assumed that the Short-tailed Albatross nesting on Midway
> come from the Torishima population?
>
> Obviously there are significant conservation issues if this pans out. The
> upside of the intense territorial dispute over the Senkaku islands is it
> might mean the albatross are left alone. Am I right that an unspoken reason
> for the quarrel (at least between PRC and ROC is the potential for
> exploitable 'seabed resources' in the area?
>
between China and Japan, made worse with island claims after WW2).
To end on a high note, the Short-tailed Albatross population have
grown well – the population now estimated at 3000 birds.
Regards
Tony
Tony Pym
Oct 14, 2011, 6:42:02 AM10/14/11
to Seabird News
Link to article in Yomiuri Shimbun (Daily Yomiuri), dtd. 10 October
2011:
http://www.yomiuri.co.jp/dy/national/T111009002543.htm
[With thanks to Simba Chan and Richard Klim for advising.]
2011:
http://www.yomiuri.co.jp/dy/national/T111009002543.htm
[With thanks to Simba Chan and Richard Klim for advising.]
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