Little penguin, Blue penguin
The Little blue penguin (Eudyptula minor) is a species of penguin that is found in New Zealand. They are also commonly known as Blue penguins owing to their slate-blue plumage. They are also known by their Māori name kororā.
The Little blue penguin is the smallest among all penguin species. Like those of all penguins, their wings have developed into flippers used for swimming. The head and upper parts are blue in color, with slate-grey ear coverts fading to white underneath, from the chin to the belly. Their flippers are blue in color. The dark grey-black beak is 3-4 cm long, the irises pale silvery- or bluish-grey or hazel, and the feet pink above with black soles and webbing. An immature individual will have a shorter bill and lighter upperparts.
Little blue penguins breed along most of the coastline of New Zealand, including the Chatham Islands. However, they do not occur in Otago, which is located on the east coast of New Zealand's South Island. They spend most of their time in the water and stay not far from the shore during the breeding season.
Little blue penguins are both diurnal and nocturnal. They typically forage by day at sea, feeding their chicks and then arranging themselves to sleep at night beside the nest. Returning to shore from the sea, these animals usually march in groups to their nesting sites. During successful breeding years, they gather in well-organized groups, marching with the same individuals on their way from and to the nesting sites. Little blue penguins are extremely noisy animals, each individual having their own unique call. They use a wide variety of calls in various situations: during the courtship, defending the territory, gathering together, showing aggression, or as a way to identify an individual.
Little blue penguins are carnivores (piscivores). Their diet mainly consists of small species of fish with a preference for anchovies and pilchards. They will also consume squid, plankton, krill as well as a small octopus. In addition, Little blue penguins eat inhabitants of the sea floor such as crustaceans, crab larvae, and sea horses.
Little blue penguins are monogamous, forming pairs and remaining together year after year. Penguin pairs can split up when one of the mates dies or after an unsuccessful nesting attempt. During the period from June to October, the birds gather into loosely organized breeding colonies. Nesting areas of little blue penguins are rocky cliffs, caves, and ground burrows. The female typically lays 1-2 eggs. The chicks hatch out after 31-40 days of incubation period. During the first 18-38 days, both parents share chick-rearing duties, taking turns every 3-4 days. By the end of this period, they relax their duties, rearing the young only at nighttime. The chicks fledge at the age of 50-65 days old, becoming completely independent at 57-78 days of age. Reproductive maturity is usually reached at 3 years of age.
The species is threatened by their natural predators as well as a decline in prey species' populations due to increased industrial fishing. Little blue penguins suffer from pollution such as oil spills. On the other hand, the expansion of human habitat and coastal erosion negatively impact populations of the little penguins.
According to IUCN Red List, the total population size of the Little blue penguin is 469,760 breeding individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are stable.
Little blue penguins are an important link in the ecosystem of their habitat. Feeding upon a wide variety of marine organisms, these birds control populations of these species. The eggs and chicks of the penguins are consumed by rats, cats, dogs, and other predators in the area. In addition, adult penguins are a key source of food for a number of predators, including seals, sharks, and orca whales.