The sub-Antarctic rockhopper and Snares penguins can cover 15,000km while they were at sea between April and October each year.
They also head off in different directions.
That's what NIWA scientists have found after fitting tags to penguins on Campbell Island and Snares Island in the Southern Ocean at the end of the moulting season before they leave for the winter.
Until now, no one knew where they went.
Of the 90 penguins tagged for the project, about 80 returned the following spring when the tags were retrieved.
The Snares penguins headed exclusively west towards Australia, while the rockhoppers went east and covered a wider section of the ocean. Several birds covered more than 15,000km over the winter.
"If they are constantly moving this averages out at about 100km a day but you also have to add on to that the distances covered vertically as the birds dive to capture food," says NIWA seabird ecologist Dr David Thompson.
The Snares penguin population is relatively stable but the rockhoppers at Campbell Island have declined by at least 21 percent since 1984.
"We think winter is pretty important and that there is almost certainly something going on in the ocean causing the population to decline," Dr Thompson said.