Little penguin

For the extinct penguin genus, see Korora.

For the Korora Linux operating system, see Korora (operating system).

Little penguin
Near burrow at night, Bruny Island, Tasmania, Australia
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Sphenisciformes
Family:	Spheniscidae
Genus:	Eudyptula
Species:	E. minor
Binomial name
Eudyptula minor (J.R.Forster, 1781)

The little penguin (Eudyptula minor) is the smallest species of penguin. The penguin, which usually grows to an average of 33 cm (13 in) in height and 43 cm (17 in) in length (though specific measurements vary by subspecies), is found on the coastlines of southern Australia and New Zealand, with possible records from Chile.

In addition to the name little penguin, several common names are in use. In Australia, they are also referred to as fairy penguins because of their tiny size. In New Zealand, they are also called little blue penguins, or just blue penguins, owing to their slate-blue plumage, and they are called kororā in Māori.

Taxonomy

The little penguin was first described by German naturalist Johann Reinhold Forster in 1781. There are several subspecies but a precise classification of these is still a matter of dispute. The holotypes of the subspecies Eudyptula minor variabilis and Eudyptula minor chathamensis are in the collection of the Museum of New Zealand Te Papa Tongarewa. The white-flippered penguin is sometimes considered a subspecies, sometimes a distinct species, and sometimes a morph. As the Australian and Otago (southeastern coast of South Island) little penguins may be a distinct species to which the specific name minor would apply, the white-flippered birds indeed belong to a distinct species, although not exactly as originally assumed.

Mitochondrial and nuclear DNA evidence suggests the split between Eudyptula and Spheniscus occurred around 25 million years ago, with the ancestors of the white-flippered and little penguins diverging about 2.7 million years ago.

Description

Little penguin at the Melbourne Zoo

Like those of all penguins, the little penguin's wings have developed into flippers used for swimming. The little penguin typically grows to between 30 and 33 cm (12 to 13 inches) tall and usually weighs about 1.5 kilogram on average (3.3 pounds). The head and upperparts are blue in colour, with slate-grey ear coverts fading to white underneath, from the chin to the belly. The flippers are blue. 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.

Like most seabirds, they have a long lifespan. The average for the species is 6.5 years, but flipper ringing experiments show in very exceptional cases up to 25 years in captivity.

Distribution and habitat

See also: List of little penguin colonies

The little penguin breeds along the entire coastline of New Zealand, the Chatham Islands, and southern Australia (including roughly 20,000 pairs on Babel Island).

Little penguins have also been reported from Chile (where they are known as Pingüino pequeño or Pingüino azul) (Isla Chañaral 1996, Playa de Santo Domingo, San Antonio, 16 March 1997) and South Africa, but it is unclear whether these birds were vagrants.

Rough estimates (as new colonies continue to be discovered) of the world population are around 350,000-600,000 animals. The species is not considered endangered, except for the white-flippered subspecies found only on Banks Peninsula and nearby Motunau Island in New Zealand. Since the 1960s, the mainland population has declined by 60-70%; though there has been a small increase on Motunau Island. But overall little penguin populations have been decreasing as well, with some colonies having been wiped out and other populations continuing to be at risk. However, new colonies have been established in urban areas.

The greatest threat to little penguin populations has been predation (including nest predation) from cats, foxes, large reptiles, ferrets and stoats. Due to their diminutive size and the introduction of new predators, some colonies have been reduced in size by as much as 98% in just a few years, such as the small colony on Middle Island, near Warrnambool, Victoria, which was reduced from approximately 600 penguins in 2001 to less than 10 in 2005. Because of this threat of colony collapse, conservationists pioneered an experimental technique using Maremma Sheepdogs to protect the colony and fend off would-be predators.

Behaviour

Little penguins are diurnal and like many penguin species, spend the largest part of their day swimming and foraging at sea. During the breeding and chick rearing seasons, little penguins will leave their nest at sunrise, forage for food throughout the day and return to their nests just after dusk. Little penguins preen their feathers to keep them waterproof. They do this by rubbing a tiny drop of oil onto every feather from a special gland above the tail.

Diet

These birds feed by hunting fish, squid and other small sea animals, for which they travel and dive quite extensively. In New Zealand, important prey items include arrow squid, slender sprat, Graham's gudgeon, red cod and ahuru. They are generally inshore feeders. The use of data loggers has provided information of the diving behaviour of little penguins. 50% of their dives go no deeper than 2 m and the mean diving time is 21 seconds. Yet, they are able to dive as deep as 20 m and remained submerged as long as 60 seconds. Little penguins play an important role in the ecosystem as not only a predator to parasites but also a host. Recent studies have shown a new species of feather mite that feeds on the preening oil on the feathers of the penguin.

Reproduction

Chick in nest burrow

Little penguin (Eudyptula minor) family exiting burrow at night, Bruny Island

Little penguins mature at different ages. The female matures at 2 years old. The male, however, matures at 3 years old. Little penguins only remain faithful to their partner in breeding seasons and whilst hatching eggs. At other times of the year they do tend to swap burrows. They exhibit site fidelity to their nesting colonies and nesting sites over successive years.

Little penguins can breed as isolated pairs, in colonies, or semi-colonially. Nests are situated close to the sea in burrows excavated by the birds or other species, or in caves, rock crevices, under logs or in or under a variety of man-made structures including nest boxes, pipes, stacks of wood or timber, and buildings. They are monogamous within a breeding season, and share incubation and chick rearing duties. They are the only species of penguin capable of producing more than one clutch of eggs per breeding season, but few populations do so. The one or two white or lightly mottled brown eggs are laid from July to mid-November, and with rarer second (or even third) clutches beginning as late as December. Incubation takes up to 36 days. Chicks are brooded for 18–38 days, and fledge after 7–8 weeks.

Little penguins typically return to their colonies to feed their chicks at dusk. The birds will tend to come ashore in small groups to provide some defence against predators which might pick off individuals one by one. In Australia, the strongest colonies are usually on cat-free and fox-free islands. However, the population on Granite Island (which is a fox, cat and dog-free island) has been severely depleted, from around 2000 penguins in 2001 down to 146 in 2009.

Relationship with humans

Feeding time at Melbourne Zoo

South of Perth, Western Australia, visitors to Penguin Island are able to view penguins in a totally natural state. Less than one hour from the centre of the city, it is possible to see little penguins in all months, including visiting sensitive areas where they remain on land for extended periods for the purposes of moulting.

At Phillip Island, a viewing area has been set up at the Phillip Island Nature Park to allow visitors to view the nightly "penguin parade". Lights and concrete stands have been erected to allow visitors to see but not photograph the birds interacting in their colony.

In Otago, New Zealand town of Oamaru, where visitors may view the birds returning to their colony at dusk. In Oamaru it is not uncommon for penguins to nest within the cellars and foundations of local shorefront properties, especially in the old historic precinct of the town. More recently, little penguin viewing facilities have been put in place at Pilots Beach, Otago Peninsula and Dunedin in New Zealand. Here visitors are guided by volunteer wardens to watch penguins returning to their burrows at dusk.

Visitors to Kangaroo Island, South Australia, have the nightly opportunity to commune with penguins at the Kangaroo Island Marine Centre in Kingscote and at the Penneshaw Penguin Centre. Several human-made enclosures have been made to support breeding and shelter, with several people clearing an area for the penguins and burying the huts, most notably The Knox School, when their efforts were filmed and broadcast in 2008 by Totally Wild. Granite Island at Victor Harbor, South Australia, has a colony of c. 100 fairy penguins where penguins can be seen every day in their natural habitat, with guided tours at dusk. There is also a penguin centre where the penguins can be viewed being fed.

In Bicheno, Tasmania, evening penguin viewing tours are offered by a local tour operator at a rookery on private land.

Mascots and logos

Linus Torvalds, the original creator of Linux (a popular operating system kernel), was once pecked by a little penguin while on holiday in Australia. Reportedly, this encounter encouraged Torvalds to select Tux as the official Linux mascot.

Penny the Little Penguin was the mascot for the 2007 FINA World Swimming Championships held in Melbourne, Victoria.

Zoological exhibits

Little penguins at Sea World, Gold Coast, Queensland, Australia (photo 2005)

Exhibits currently exist at the Adelaide Zoo, Melbourne Zoo, the National Zoo & Aquarium in Canberra, Perth Zoo and the Taronga Zoo in Sydney.

A colony of little penguins is also exhibited at Sea World, on the Gold Coast, Queensland, Australia. In early March, 2007, 25 of the 37 penguins died from an unknown toxin following a change of gravel in their enclosure. It is still not known what caused the deaths of the little penguins, and it was decided not to return the 12 surviving penguins to the same enclosure in which the penguins became ill. A new enclosure for the little penguin colony was opened at Sea World in 2008.

Little penguin at night at the
St Kilda breakwater

Predators

Little penguins in the wild are sometimes preyed upon by New Zealand fur seals. A study done by researchers from the South Australian Research and Development Institute found that roughly 40 percent of seal droppings in South Australia's Granite Island area contained little penguin remains.

On land, little penguins are vulnerable to attack from domestic and feral dogs and cats. Attacks on Kangaroo Island and in Tasmania have resulted in significant impacts to several populations.

Little penguins on Middle Island in Warrnambool, Victoria were subject to heavy predation by foxes, which could reach the island at low tide by a tidal sand bridge. The deployment of Maremma sheepdogs to protect the penguin colony has deterred the foxes and enabled the penguin population to rebound. This is in addition to the support from groups of volunteers who work to protect the penguins from attack at night.

In Sydney, snipers have been deployed to protect a colony of little penguins. This effort is in addition to support from local volunteers who work to protect the penguins from attack at night.

See also

• Animals portal

Further reading

• Williams, Tony D. (1995). The Penguins. Oxford, England: Oxford University Press. ISBN 0-19-854667-X. 

External links

• Little penguins at New Zealand Penguins
• Little penguins at the International Penguin Conservation
• The Blue Penguin Trust (New Zealand)
• Philip Island Nature Park website
• Gould's The Birds of Australia plate
• Roscoe, R. "Little (Blue) Penguin". Photo Volcaniaca. Retrieved 13 April 2008.