Known as Fairy penguins, blue penguins, and little blue penguins, this species is the smallest of all penguins; a fully developed adult can weigh only 2.6 lb. They have a fragile and delicate appearance highlighted by a bluish color unique among all species of penguins. Little blue penguins are mainly nocturnal as they perform most of their activity during the night creating small groups of about ten members or less. They are not migratory and stay close to their colonies most of the time. Predatory birds like skuas, gulls and sheathbills are the primary predators of eggs and chicks, while introduced animals like rats, dogs, and cats can be a problem for both chicks and adults.