Tracking tawaki penguins to their feeding grounds

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Tracking tawaki penguins to their feeding grounds

September 03, 2018 - 18:11
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Researchers have discovered where tawaki penguins go to feed before they start their annual moult.

The tawaki penguins' small size belies their incredible achievement of making mammoth migrations to feed.

Researchers at the University of Otago have discovered that the tawaki penguin, although just 60cm high, have no qualms about travelling nearly 7,000 kilometres to feed.

Also known as Fiordland penguins (Eudyptes pachyrhynchus), they leave the western coast of New Zealand's South Island for eight to ten weeks after their chicks have fledged. It is during this crucial trip that they recover from their chick-rearing duties and put on weight in preparation for their annual moult.

Little is known about this penguin, so a team of international researchers sought to find out where these birds go to. From November 2016 to March 2017, they used satellite transmitters to track 17 adult Tawaki penguins on their feeding journey.

Thus, it was discovered that the tawaki penguins head to one of two feeding grounds, either near the subtropical front, south of Tasmania, or another one farther south near the subantarctic front.

Travelling between 20 to 80 kilometres daily, the entire journey would mean that they cover a distance of between 3,500 and 6,800 km on their 69-day migration.

Describing it as an incredible achievement, co-author Dr Klemens Pütz from the Antarctic Research Trust, commented: "The question is why the penguins leave on such an epic journey, at a time when the ocean productivity along their coastal breeding sites reaches its peak. There should be more than enough food for them just on their doorstep.”

The authors speculate that it is because the birds are just following their instincts.

Lead author Thomas Mattern explained, "We believe that this extraordinary behaviour could be a remnant from an ancestral penguin species that evolved further south in the sub-Antarctic region before populating the New Zealand mainland. This would also explain why the species breeding range is concentrated to the southern coastlines of New Zealand; if breeding further north, this migratory behaviour would simply not be feasible."

The study's findings has been published on 29 August in the journal PLOS ONE.

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