A century ago, a rookery of roughly 3 million king penguins on sub-Antarctic Macquarie Island was nearly wiped out as a New Zealand blubber merchant boiled the birds to extract oil for lamps. Saved by one of the first
international wildlife campaigns, the 4,000 remaining penguins on Macquarie Island have rebounded to 500,000 birds, and new genetic tests show that the population’s genetic diversity is close to pre-slaughter levels. Tim Heupink of Griffith University in Australia compared DNA from 17 penguins today with that from the bones of 1,000-year-old penguins dug up on the island. He found that the recovered population of king penguins is nearly as genetically diverse as the older population, offering hope that other beleaguered populations of birds and mammals can regain not just their numbers but also their genetic diversity. “It is remarkable that a nearly extinct population has recovered levels of past genetic diversity in only 80 years,” said Heupink, whose study was published in the journal, Biological Letters.