AWC Summer Project Completion Report. By Charlotte Till, University of Otago.
Project Title:
Genetic investigation into New Zealand blue eyed shags and other coastal birds.
Over the period Nov 14th 2011 through to Feb 4th 2012 a genetic investigation was undertaken
into modern and prehistoric shag samples from New Zealand, and Sub Antarctic and South
America. This work followed on from previous research undertaken in 2011 which resulted in
my genetics honours level dissertation. As such I already had all primer pairs that would be
needed and had a solid grasp on the research area.
In order to address the aims of my summer project new modern shag samples were obtained
from Te Papa as well as from Martyn Kennedy. Ancient shag samples were obtained from
Paul Scofield and collected on a recent field trip to the Nelson region. A summary of samples
investigated over the summer can be seen below.
Sample Type
Modern
Modern
Modern
Modern
Modern
Modern
Modern
Modern
Ancient
Shag Name
Falkland Island
Stewart Island shag
Stewart Island shag
Guanay shag
Kerguelen shag
Kerguelen shag
Kerguelen shag
Kerguelen shag
Labelled as King shag
Obtained from
Identifier
Falkland Island 2008
Falk
Karitane, Otago, 2011
SIS K
Warrington Beach, Otago, 2011
SIS W
Martyn Kennedy
GBN41
Te Papa 1985
89/a
Te Papa 1985
11/b
Te Papa 1985
12/b
Te Papa 1985
79/a
Paul Scofield, Red Cliffs,
AV158036
Canterbury
Ancient
Labelled as King shag Paul Scofield, Red Cliffs,
AV16267
Canterbury
Ancient
Labelled as King shag Paul Scofield, Wairau Bar,
AV10995
Marlborough
Ancient
Labelled as King shag Paul Scofield, Marfells Beach,
AV 3042
Marlborough
Ancient
Labelled as King shag Paul Scofield, Marlborough
AV12878
Ancient
Labelled as King shag Paul Scofield, Doubtless Bay,
AV6564
Northland
Ancient
Labelled as King shag Catherine Collins & Jon Waters,
Broken
Delaware Bay, Nelson
Ancient
Labelled as King shag Catherine Collins & Jon Waters,
Whole
Delaware Bay, Nelson
Note: Samples from Paul Scofield are from Canterbury Museum. A distribution map of
ancient samples and Stewart Island shag distribution is shown on page five.
All modern samples were extracted using the DNeasy extraction method and PCR was carried
out using a selection of primers previously used to amplify across Control Region one of the
mitochondrial genome (Till, 2011). The Falkland Island and two Stewart Island shag samples
were the only modern samples to be successfully amplified and sequenced. Despite fresh
extractions being carried out using both the DNeasy method and standard Chelex method no
further modern samples (i.e., the Guanay and Kerguelen shags) were able to be successfully
amplified for any primer combinations tested.
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All ancient samples were extracted under strict aDNA protocols and conditions in the aDNA
lab (Anthropology Department, University of Otago). The two Red Cliff samples and the
Wairau Bar sample were successfully amplified using overlapping aDNA primer pairs
(designed during my honours) and successfully sequenced. The sequencing results were
confirmed by independent replication. Of the remaining ancient samples amplification for one
of the primer pairs has been successful for three samples (13042, AV6564 & AV12878) but
despite one attempt this result has yet to be successfully replicated, so sequencing of these
samples was not undertaken. Access to the aDNA lab is highly restricted and time constraints
with other lab users limited the amount of time that could be spent there. In the coming year I
aim to try to get successful replication of these samples and later sequence them.
Results
The two Stewart Island shag samples fit within the northern cluster of Stewart Island shags as
was predicted (see Figure 1). The Falkland Island sample also fits nicely into the South
American / Sub Antarctic group.
Of the three successfully sequenced ancient samples all were labelled as King shag, but
sequencing of these samples reveals that AV158036 and AV10995 are Stewart Island shag
remains and that AV16267 is most likely a Pied shag (see Figure 2; samples with the same
haplotype have been collapsed to representative samples in this tree).
Conclusions
The results of the aDNA portion of my summer research are two fold. 1) Physical
identification of bones can be flawed resulting in misrepresentation and 2) the historic range
of the Stewart Island shag could have been at least as far north as Wairau Bar near Blenheim.
The results of the modern sequencing support the bigger picture previously found during my
honours work of post glacial colonisation of South America and the Sub Antarctic while NZ
and its close off shore islands remained ice free. Also evident is a North – South split within
the mitochondrial lineages of the Stewart Island shag, with the northern cluster more closely
aligned with the Chatham Island shags.
Acknowledgements
I would like to thank Martyn Kennedy for his direction and assistance in the lab, and
Catherine Collins for all he help in the aDNA lab. Also thanks must go to Catherine Collins,
Jon Waters and Paul Schofield for providing samples. Lastly a very big thank you to the
AWC for the opportunity to undertake this research which helps to fill in some of the ‘gaps’ I
was not able to address in 2011.
References
Till, C. 2011. BSc Hons (Genetics), University of Otago. Species, sub species or new species?
A phylogenetic analysis of the Blue eyed shag complex.
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Figure 1.
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Figure 2.
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QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
Red Cliffs
Doubtless Bay
Delaware Bay
Wairau Bar (also Marfells Beach, and general Marlborough area)
Modern boundary between Northern and Southern Stewart Island shag groups
Approximate modern range extent of Stewart Island shags, extending from Southland and Stewart
Island up to Oamaru.
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