Wellington: New Zealand scientists are preparing a study to solve one of nature`s great mysteries, the disappearance of a rapidly dwindling breed of penguin every winter.
Scientists from the National Institute of Water and Atmospheric Research (NIWA) are being funded by the U.S.-based National Geographic to discover where the missing rockhopper penguins go in winter.
A team of scientists will travel to the penguins` breeding ground in New Zealand`s sub-Antarctic Campbell Island to attach 88 miniaturized tracking tags to penguins`legs next year.
“We don`t know where the penguins go during winter," said NIWA scientist David Thompson.
“It could be a crucial stage in the breeding cycle for them. To successfully raise chicks, they need to come back to Campbell Island at the start of the breeding season in good condition," he said.
"If they have a bad winter, they will come back to Campbell Island in poor condition. This stage of the annual cycle of the birds is likely to be very significant. To know nothing about where this stage takes place is a crucial gap in our understanding of the factors affecting the penguin populations."
From 1942 to 1985, the rockhopper penguin population at Campbell Island declined from about 800,000 breeding pairs to just 51,000 pairs, and the decline had continued since.
"They are unlikely to become extinct in the near future, but this represents a massive decline," said Thompson.
The data obtained from the tags would shed light on the winter movements, distribution and habitat use of rockhopper penguins.
"I wouldn``t think they go too far, they clearly can``t fly, however they can swim pretty fast," said Thompson.
"They leave Campbell Island in April, and don``t reappear until early October. That gives them a few months to go exploring. I suspect they don``t go too far south, nor are they likely to go too far north. They probably stay at the same latitude, but disperse away from the island, spending that time feeding and regaining condition."
Diminished food stocks probably caused the falling population, he said.
"They eat little krill, crustaceans, juvenile and small fish and small squid. They have quite a broad diet. It``s thought that fluctuations in sea temperatures may have led to a reduction in the abundance or availability of their prey," said Thompson.
The rockhopper stands about 40 cm tall and weighs up to 4 kg, and has distinctive bright red eyes and long yellow crests on its head.