Blue penguin facts

* The blue penguin is the world's smallest and the only penguin species that is nocturnal on land.

* Although quite common, its size and unusual habits make it rarely seen.

* The penguins come ashore only in darkness and live in burrows.

* They breed in burrows, under trees and other vegetation, in piles of driftwood, in rock crevices, under buildings and in caves.

* Blue penguins usually breed for the first time at 2-3 years of age.

* Their ability to fledge chicks from more than one clutch during a single breeding season makes them unique among penguin species.

* The core egg-laying period for most of NZ is September to November.

* Eggs are incubated for 36 days.

* Both parents share incubation and feeding duties; at least one adult will stay in the burrow all day throughout incubation and guard periods.

* The chicks are guarded for the first 2-3 weeks, after which both parents must go to sea to keep up the supply of fish.

* Chick growth is rapid, with adult weight (1kg) being achieved in 4-5 weeks.

* Chicks usually fledge at 8 weeks and are independent from then on.

* There is a high rate of juvenile mortality, but individuals can reach up to 25 years of age.

Source: New Zealand Herald