Wellington, Feb 10 (IANS): An international study has documented one of the most rapid biological transitions ever with the extinction of a unique New Zealand penguin and its replacement by another breed.

Study leaders from the University of Otago said Tuesday that the team used carbon dating and ancient DNA analysis of archaeological penguin remains to determine that the process happened within just a few decades.

"Previous research has shown that at the time of human arrival, New Zealand was inhabited by the waitaha penguin. Hunting and habitat change apparently caused the extinction of this unique mainland penguin, before the yellow-eyed penguin later arrived here from the sub-Antarctic," Xinhua news agency quoted researcher Nic Rawlence as saying in a statement.

"Until now, we really had no idea when one species went extinct and the other colonised."

The study had shown that the waitaha penguin became extinct around the same time as the giant flightless moa bird, within 200 years of the Polynesian settlement of New Zealand, before 1500 AD.

The yellow-eyed penguin replaced the waitaha within just a few decades, in the early 1500s.

"This very rapid biological shift implies a substantial change in human pressure around this time. Interestingly, recent archaeological studies similarly suggest that the Maori population in southern New Zealand declined around 1500 AD, and coincided with a major dietary shift," associate professor Ian Smith said in the statement.

The team members came from the universities of Auckland, Otago, Adelaide (Australia) and Oslo (Norway), as well as two New Zealand museums.