The blue or little penguin (Eudyptula minor), also known in Maori as korora, can be found in many places around New Zealand and Southern Australia and is the world's smallest penguin. They only come ashore under the cover of darkness and live underground in burrows. Although quite common, its small size and unusual habits make it rarely seen. The blue penguin stands just 25 cm tall and weighs a little over 1 kilogram. The plumage is slate-blue with a bright white belly. Juveniles are indistinguishable from adults. Both sexes are alike, although the male is a little heavier and usually has a larger bill. There are several distinct races of blue penguins and some argue that they should be split up into sub-species. Perhaps the most distinct is the "white-flippered" penguin of Canterbury, however genetic tests have shown it not to be as distinct as its plumage would suggest.