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Christchurch, New Zealand

Holdaway R.N.,Palaecol Research Ltd | Holdaway R.N.,University of Canterbury | Williams M.,Victoria University of Wellington | Hawke D.J.,Christchurch Polytechnic Institute of Technology
Notornis | Year: 2013

Bone samples from 2 surviving populations of New Zealand's endemic and endangered brown teal (Anas chlorotis) had a much smaller distribution of stable isotopic values (δ13C, δ15N) than those from Holocene-age fossil bones of the same species. Comparison with δ13C and δ15N values from 2 other taxa of known ecologies indicated that some brown teal were forest floor omnivores. The results indicate that the riparian and estuarine wetlands occupied by present natural populations represent only an extreme, truncated part of the species' potential habitat. To aid present conservation efforts we suggest that brown teal be released into forested areas and islands managed as mammal-free enclaves to test whether modern birds can survive in habitats once occupied by now-extirpated populations. Palaeoecological studies, including stable isotope analyses, can be used to identify conservation options not obvious from research on declining remnant populations in anthropogenic environments. © The Ornithological Society of New Zealand, Inc. Source

Horton T.W.,Geological science | Holdaway R.N.,Geological science | Holdaway R.N.,University of Canterbury | Holdaway R.N.,Palaecol Research Ltd | And 10 more authors.
Biology Letters | Year: 2011

Humpback whale seasonal migrations, spanning greater than 6500 km of open ocean, demonstrate remarkable navigational precision despite following spatially and temporally distinct migration routes. Satellite-monitored radio tag-derived humpback whale migration tracks in both the South Atlantic and South Pacific include constant course segments of greater than 200 km, each spanning several days of continuous movement. The whales studied here maintain these directed movements, often with better than 18 precision, despite the effects of variable seasurface currents. Such remarkable directional precision is difficult to explain by established models of directional orientation, suggesting that alternative compass mechanisms should be explored. © 2011 The Royal Society. Source

Holdaway R.N.,Palaecol Research Ltd | Holdaway R.N.,University of Canterbury | Allentoft M.E.,University of Canterbury | Allentoft M.E.,Copenhagen University | And 4 more authors.
Nature Communications | Year: 2014

New Zealand moa (Aves: Dinornithiformes) are the only late Quaternary megafauna whose extinction was clearly caused by humans. New Zealand offers the best opportunity to estimate the number of people involved in a megafaunal extinction event because, uniquely, both the Polynesian settlement of New Zealand and moa extinction are recent enough to be dated with a high degree of precision. In addition, the founding human population can be estimated from genetic evidence. Here we show that the Polynesian population of New Zealand would not have exceeded 2,000 individuals before extinction of moa populations in the habitable areas of the eastern South Island. During a brief (<150 years) period and at population densities that never exceeded ~0.01 km-2, Polynesians exterminated viable populations of moa by hunting and removal of habitat. High human population densities are not required in models of megafaunal extinction. © 2014 Macmillan Publishers Limited. Source

Allentoft M.E.,Copenhagen University | Heller R.,Copenhagen University | Holdaway R.N.,Palaecol Research Ltd | Holdaway R.N.,University of Canterbury | Bunce M.,Curtin University Australia
Heredity | Year: 2015

By analysing ancient DNA (aDNA) from 74 14 C-dated individuals of the extinct South Island giant moa (Dinornis robustus) of New Zealand, we identified four dyads of closely related adult females. Although our total sample included bones from four fossil deposits located within a 10 km radius, these eight individuals had all been excavated from the same locality. Indications of kinship were based on high pairwise genetic relatedness (r XY) in six microsatellite markers genotyped from aDNA, coupled with overlapping radiocarbon ages. The observed r XY values in the four dyads exceeded a conservative cutoff value for potential relatives obtained from simulated data. In three of the four dyads, the kinship was further supported by observing shared and rare mitochondrial haplotypes. Simulations demonstrated that the proportion of observed dyads above the cutoff value was at least 20 times higher than expected in a randomly mating population with temporal sampling, also when introducing population structure in the simulations. We conclude that the results must reflect social structure in the moa population and we discuss the implications for future aDNA research. © 2015 Macmillan Publishers Limited. Source

Allentoft M.E.,Murdoch University | Allentoft M.E.,University of Canterbury | Oskam C.,Murdoch University | Houston J.,Murdoch University | And 9 more authors.
PLoS ONE | Year: 2011

We present the first set of microsatellite markers developed exclusively for an extinct taxon. Microsatellite data have been analysed in thousands of genetic studies on extant species but the technology can be problematic when applied to low copy number (LCN) DNA. It is therefore rarely used on substrates more than a few decades old. Now, with the primers and protocols presented here, microsatellite markers are available to study the extinct New Zealand moa (Aves: Dinornithiformes) and, as with single nucleotide polymorphism (SNP) technology, the markers represent a means by which the field of ancient DNA can (preservation allowing) move on from its reliance on mitochondrial DNA. Candidate markers were identified using high throughput sequencing technology (GS-FLX) on DNA extracted from fossil moa bone and eggshell. From the 'shotgun' reads, >60 primer pairs were designed and tested on DNA from bones of the South Island giant moa (Dinornis robustus). Six polymorphic loci were characterised and used to assess measures of genetic diversity. Because of low template numbers, typical of ancient DNA, allelic dropout was observed in 36-70% of the PCR reactions at each microsatellite marker. However, a comprehensive survey of allelic dropout, combined with supporting quantitative PCR data, allowed us to establish a set of criteria that maximised data fidelity. Finally, we demonstrated the viability of the primers and the protocols, by compiling a full Dinornis microsatellite dataset representing fossils of c. 600-5000 years of age. A multi-locus genotype was obtained from 74 individuals (84% success rate), and the data showed no signs of being compromised by allelic dropout. The methodology presented here provides a framework by which to generate and evaluate microsatellite data from samples of much greater antiquity than attempted before, and opens new opportunities for ancient DNA research. © 2011 Allentoft et al. Source

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