Graeme A. Taylor

Publications (4)9.36 Total impact

• Article: Molecular evidence for the identity of the Magenta petrel.

  Hayley A Lawrence, Craig D Millar, Michael J Imber, David E Crockett, Judith H Robins, R Paul Scofield, Graeme A Taylor, David M Lambert
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  ABSTRACT: A lone petrel was shot from the decks of an Italian warship (the 'Magenta') while it was sailing the South Pacific Ocean in 1867, far from land. The species, unknown to science, was named the 'Magenta petrel' (Procellariiformes, Procellariidae, Pterodroma magentae). No other specimens of this bird were collected and the species it represented remained a complete enigma for over 100 years. We compared DNA sequence of the mitochondrial cytochrome b gene from the Magenta petrel to that of other petrels using phylogenetic methods and ancient DNA techniques. Our results strongly suggest that the Magenta petrel specimen is a Chatham Island taiko. Furthermore, given the collection location of the Magenta petrel, our finding indicates that the Chatham Island taiko forages far into the Pacific Ocean (near South America). This has implications for the conservation of the taiko, one of the world's rarest seabirds.
  Molecular Ecology Resources 03/2009; 9(2):458-461. · 3.06 Impact Factor
• Source

  Available from: griffith.edu.au

  Article: High mitochondrial and nuclear genetic diversity in one of the world’s most endangered seabirds, the Chatham Island Taiko ( Pterodroma magentae )

  Hayley A. Lawrence, Graeme A. Taylor, Craig D. Millar, David M. Lambert
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  ABSTRACT: Interpreting the levels of genetic diversity in organisms with diverse life and population histories can be difficult. The processes and mechanisms regulating this diversity are complex and still poorly understood. However, endangered species typically have low genetic variation as a consequence of the effects of genetic drift in small populations. In this study we examine genetic variation in the critically endangered Chatham Island Taiko (Tchaik, Pterodroma magentae), one of the world’s rarest seabirds. The Taiko has a very small population size of between 120 and 150 individuals, including just 8–15 breeding pairs. We report surprisingly high mitochondrial and nuclear genetic diversity in this critically endangered long-lived species. We hypothesise that the present Taiko population has retained a significant proportion of its past genetic diversity. However, it is also possible that undiscovered birds are breeding in unknown areas, which could increase the population size estimate. Importantly, from a conservation perspective, we show that the high level of variation is unlikely to be maintained in the future since chicks currently being born have only a limited number of the mitochondrial DNA haplotypes found in adults. Reduced genetic variation will mean that our ability to infer past events and the population history of Taiko using genetics could soon be lost and the power to determine, for example, parentage and other close order relationships will be diminished. Therefore, the maintenance of genetic diversity in future generations is an important consideration for conservation management of the Taiko.
  Conservation Genetics 09/2008; 9(5):1293-1301. · 1.61 Impact Factor
• Article: New genetic approach to detecting individuals of rare and endangered species.

  Hayley A Lawrence, Graeme A Taylor, David E Crockett, Craig D Millar, David M Lambert
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  ABSTRACT: Many rare and endangered species are difficult to locate, observe, and study. Consequently, many individuals, breeding pairs, and even populations of such species could remain undetected. Genetic markers can potentially be used to detect the existence of undiscovered individuals and populations, and we propose a method to do so that requires 3 conditions. First, sampling of the known population(s) of the target species must be comprehensive. Second, the species must display a reasonable level of philopatry and genetic structuring. Third, individuals must be able to be caught outside of breeding locations (e.g., at courtship or feeding areas, in flight), and the level of recapture must be reasonably high. We applied our method to the Chatham Island Taiko (Pterodroma magentae), one of the world's most endangered seabirds. We sequenced the Taiko mitochondrial cytochrome b gene and both copies of a fragment of the duplicated domain I of the control region. Twenty-one haplotypes were revealed, including 4 (19%) not found in birds at known burrows. These results suggest there are more burrow groups yet to be located. The species is a pelagic gadfly petrel that inhabits land only in the breeding season during which it is nocturnal and nests in burrows. Taiko burrows are situated in dense forest in a remote area of Chatham Island, and are consequently difficult to locate and study. It is important that all Taiko burrows be discovered to enable monitoring and protection of the birds from exotic predators.
  Conservation Biology 09/2008; 22(5):1267-76. · 4.69 Impact Factor
• Article: Excess of unpaired males in one of the World's most endangered seabirds, the Chatham Island taiko Pterodroma magentae

  Hayley A. Lawrence, Craig D Millar, Graeme A. Taylor, Linda D. Macdonald, David M Lambert
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  ABSTRACT: The Chatham Island taiko Pterodroma magentae (tchaik) is one of the World's most endangered seabirds with a population size of between 120-150 individuals that includes only 8-15 breeding pairs. Molecular techniques were used to identify the sex of taiko, which is difficult to assign morphologically. Blood samples were obtained from almost the entire known living population and from some birds now thought to be dead. We report an approximately even sex ratio in taiko chicks and adults associated with breeding burrows, but a large male-biased ratio in non-breeding adult birds caught on the ground. This finding suggests that unpaired males may be having difficulty in attracting females to burrows and that this situation may be an example of the Allee effect, that reduced density of potential mates acts to decrease population productivity. Identification of the sex of taiko using a molecular technique has important implications for the conservation management of this critically endangered species, including the future transfer of taiko chicks to a predator-excluded breeding site. Yes Yes