Excess of unpaired males in one of the World's most endangered seabirds, the Chatham Island taiko Pterodroma magentae
Author(s)
Lawrence, HA
Millar, CD
Taylor, GA
Macdonald, LD
Lambert, DM
Griffith University Author(s)
Year published
2008
Metadata
Show full item recordAbstract
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 ...
View more >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.
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View more >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.
View less >
Journal Title
Journal of Avian Biology
Volume
39
Issue
3
Subject
Biological sciences
Molecular evolution
Agricultural, veterinary and food sciences