Little penguin

The little penguin (Eudyptula minor) is the smallest species of penguin. It grows to an average of 33 cm (13 in) in height and 43 cm (17 in) in length, though specific measurements vary by subspecies.^[2][3] It is found on the coastlines of southern Australia and New Zealand, with possible records from Chile. In Australia, they are often called fairy penguins. In New Zealand, they are more commonly known as little blue penguins or blue penguins owing to their slate-blue plumage. They are also known by their Māori name: kororā.

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^[4] and Eudyptula minor chathamensis^[5] 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^[6] 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.^[7]

Description

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. Their flippers are blue in colour. 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.^[8]

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.^[9]

Distribution and habitat

The little penguin breeds along the entire coastline of New Zealand, the Chatham Islands, and southern Australia (including roughly 20,000 pairs^[10] on Babel Island). Australian colonies exist in New South Wales, Victoria, Tasmania, South Australia and Western Australia. 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. As new colonies continue to be discovered, rough estimates of the world population are around 350,000-600,000 animals.^[3]

New Zealand

Overall, little penguin populations in New Zealand have been decreasing. Some colonies have gone extinct and others continue to be at risk.^[3] Some new colonies have been established in urban areas.^[2] The species is not considered endangered in New Zealand, with the exception of the white-flippered subspecies found only on Banks Peninsula and nearby Motunau Island. Since the 1960s, the mainland population has declined by 60-70%; though there has been a small increase on Motunau Island.

Australia

Australian little penguin colonies primarily exist on offshore islands where they are protected from feral terrestrial predators and human disturbance. Colonies are found from Port Stephens in northern New South Wales around the southern coast to Fremantle, Western Australia.

New South Wales

An endangered population of little penguins exists at Manly, North Sydney Harbor. The population is protected under the NSW Threatened Species Conservation Act 1995^[11] and has been managed in accordance with a Recovery Plan since the year 2000. The population once numbered in the hundreds, but has decreased to around 60 pairs of birds. The decline is believed to be mainly due to loss of suitable habitat, attacks by foxes and dogs and disturbance at nesting sites.^[12]

The largest colony in New South Wales is on Montague Island. Up to 8000 breeding pairs are known to nest there each year.^[13]

Jervis Bay Territory

A population of approximately 5,000 breeding pairs exists on Bowen Island. The colony has increased from 500 pairs in 1979 and 1500 pairs in 1985. During this time, the island was privately leased. The island was vacated in 1986 and is currently controlled by the federal government.^[14]

South Australia

In South Australia, many little penguin colony declines have been identified across the state. In some cases, colonies have declined to extinction (including the Neptune Islands, West Island, Wright Island, Pullen Island and several colonies on western Kangaroo Island), while others have declined from thousands of animals to few (Granite Island and Kingscote). A report released in 2011 presented evidence supporting the listing of the statewide population or the more closely monitored sub-population from St. Vincent's Gulf as Vulnerable under South Australia's National Parks & Wildlife Act 1972.^[15] As of 2014, the little penguin is not listed as a species of conservation concern,^[16] despite ongoing declines at many colonies.

Tasmania

Tasmanian little penguin population estimates range from 110,000–190,000 breeding pairs of which less than 5% are found on mainland Tasmania. Ever-increasing human pressure is predicted to result in the extinction of colonies on mainland Tasmania.^[17]

Victoria

The largest colony of little penguins in Victoria is located at Phillip Island, where the nightly 'parade' of penguins across Summerland Beach has been a major tourist destination, and more recently a major conservation effort, since the 1920s. Phillip Island is home to an estimated 32,000 breeding pairs (70,000 birds).^[18] Little penguins can also be seen in the vicinity of the St Kilda, Victoria pier and breakwater. The breakwater is home to a colony of little penguins which have been the subject of a conservation study since 1986.^[19]

Little penguin habitats also exist at a number of other locations, including London Arch and The Twelve Apostles along the Great Ocean Road, Wilson's Promontory and Gabo Island.^[20]

Western Australia

The largest colony of little penguins in Western Australia is believed to be located on Penguin Island. An estimated 1,000 pairs nest there during the winter.^[21] Penguins are also known to nest on Garden Island and Carnac Island which lie north of Penguin Island. Many islands along Western Australia's southern coast are likely to support little penguin colonies, though the status of these populations are largely unknown. An account of little penguins on Bellinger Island published in 1928 numbered them in their thousands. Visiting naturalists in November 1986 estimated the colony at 20 breeding pairs.^[22] The account named another substantial colony 12 miles from Bellinger Island and the same distance from Cape Pasley.^[23] Little penguins are known to breed on some islands of the Recherche Archipelago, including Woody Island where day-tripping tourists can view the animals. A penguin colony exists on Mistaken Island in King George Sound near Albany.^[24] Historical accounts of little penguins on Newdegate Island at the mouth of Deep River^[25] and on Breaksea Island near Torbay also exist.

Threats

Culling

In 1930 in Tasmania, it was believed that little penguins were competing with mutton-birds, which were being commercially exploited. An "open season" in which penguins would be permitted to be killed was planned in response to requests from members of the mutton-birding industry.^[26]

Human development

The impacts of human habitation in proximity to little penguin colonies include collisions with vehicles,^[27] direct harassment, burning and clearing of vegetation and housing development.^[17]

Human interference

Penguins are vulnerable to interference by humans, especially while they are ashore during molt or nesting periods. In 1949, penguins on Phillip Island in Victoria became victims of human cruelty, with some kicked and others thrown off a cliff and shot at. These acts of cruelty prompted the state government to fence off the rookeries.^[28] More recent examples of destructive interference can be found at Granite island, where in 1994 a penguin chick was taken from a burrow and abandoned on the mainland, a burrow containing penguin chicks was trampled and litter was discarded down active burrows.^[29] In 1998, two incidents in six months resulted in penguin deaths. The latter, which occurred in May, saw 13 penguins apparently kicked to death.^[30]

Interactions with fishing

Some little penguins are drowned when amateur fishermen set gill nets near penguin colonies. Discarded fishing line can also present an entanglement risk and contact can result in physical injury, reduced mobility or drowning.^[17] In 2014, a group of 25 dead little penguins were found on Altona Beach in Victoria. Necropsies concluded that the animals had died after becoming entangled in net fishing equipment, prompting community calls for a ban on net fishing in Port Phillip Bay.^[31]

In the 20th century, little penguins were intentionally shot or caught by fishermen to use as bait in pots for catching crayfish (Southern rock lobster) or by line fishermen.^[32][33][34] Colonies were targeted for this purpose in various parts of Tasmania^[35][36] including Bruny Island^[37] and West Island, South Australia.

Oil spills

Oil spills can be lethal for penguins and other sea birds. Oil is toxic when ingested and penguins' buoyancy and the insulative quality of their plumage is damaged by contact with oil.^[17] Little penguin populations have been significantly affected during two major oil spills at sea: the Iron Baron oil spill off Tasmania's north coast in 1995 and the grounding of the Rena off New Zealand in 2011.

Plastic pollution

Plastics are swallowed by little penguins, who mistake them for prey items. They present a choking hazard and also occupying space in the animal's stomach. Indigestible material in a penguin's stomach can contribute to malnutrition or starvation. Other larger plastic items, such as bottle packaging rings can become entangled around penguins' necks, affecting their mobility.^[17]

Predation

Threats to little penguin populations include predation (both adult and nest predation) by a variety of terrestrial animals including cats, dogs, rats, foxes, large reptiles, ferrets and stoats.^{[2][3][38][39]} 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.^[40]

Uncontrolled dogs or feral cats can have sudden and severe impacts on penguin colonies (more than the penguin's natural predators) and may kill many individuals. Examples of colonies affected by dog attacks include Manly, New South Wales,^[41] Penneshaw, South Australia,^[42] Red Chapel Beach, Tasmania,^[43] Penguin Island, Western Australia and Little Kaiteriteri Beach, New Zealand.^[44]

A suspected stoat or ferret attack at Doctor's Point near Dunedin, New Zealand claimed the lives of 29 little blue penguins in November 2014.^[45]

A fox was believed responsible for the deaths of 53 little penguins over several nights on Granite Island in 1994.^[46] In June 2015, 26 penguins from the Manly colony were killed in 11 days. A fox believed responsible was eventually shot in the area and an autopsy is expected to prove or disprove its involvement.^[39] In November 2015 a fox entered the little penguin enclosure at the Melbourne Zoo and killed 14 penguins, prompting measures to further "fox proof" the enclosure.^[47]

Prey availability

Variation in prey abundance and distribution from year to year causes young birds to be washed up dead from starvation or in weak condition.^[17]

Predator management

Little penguins in the wild are sometimes preyed upon by New Zealand fur seals. A study conducted 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.^[48][49]

They are also preyed upon by white-bellied sea eagles. These large birds-of-prey are endangered in South Australia and not considered a threat to colony viability.

On land, little penguins are vulnerable to attack from domestic and feral dogs and cats. Attacks on Kangaroo Island,^[42] at Manly^[41] in Tasmania^[43] and in New Zealand^[44] have resulted in significant impacts to several populations. Management strategies to mitigate the risk of attack include establishing dog-free zones near penguin colonies and introducing regulations to ensure dogs to remain on leashes at all times in adjacent areas.

Little penguins on Middle Island off Warrnambool, Victoria were subject to heavy predation by foxes, which were able to 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.^[50][51]

This is in addition to the support from groups of volunteers who work to protect the penguins from attack at night. The first Maremma sheepdog to prove the concept was Oddball, whose story inspired a feature film of the same name.^[52] The film Oddball is scheduled for release in 2015.^[53] In December 2015, the BBC reported, "The current dogs patrolling Middle Island are Eudy and Tula, named after the scientific term for the fairy penguin: Eudyptula. They are the sixth and seventh dogs to be used and a new puppy is being trained up [...] to start work in 2016.^[52]

In Sydney, snipers have been deployed to protect a colony of little penguins.^[54] This effort is in addition to support from local volunteers who work to protect the penguins from attack at night.

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 small clupeoid fish, cephalopods and crustaceans, for which they travel and dive quite extensively.^[55][56] In New Zealand, important prey items include arrow squid, slender sprat, Graham's gudgeon, red cod and ahuru.^[57] Since the year 2000, the little penguins of Port Phillip Bay's diet has consisted mainly of barracouta, anchovy, and arrow squid. Sardines previously featured more prominently in southern Australian little penguin diets prior to mass sardine mortality events of the 1990s. These mass mortality events affected sardine stocks over 5,000 kilometres of coastline.^[58]

They are generally inshore feeders.^[59] 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.^[60] Yet, they are able to dive as deep as 20 m and remained submerged as long as 60 seconds.^[61] 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.^[62]

Reproduction

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.^[57] 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 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.^[57]

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

Little penguins have long been a curiosity to humans, and to children in particular. Captive animals are often exhibited in zoos. Historically, the animals have also been used as bait to catch Southern rock lobster, captured for amusement and eaten by ship-wrecked sailors and castaways to avoid starvation.^[63][64][65] They have also been the victims of malicious attacks by humans and incidental bycatch by fishermen using nets.^[66] The sites of many breeding colonies have developed into tourist destinations which provide an economic boost for coastal and island communities in Australia and New Zealand. These locations also often provide facilities and volunteer staff to support population surveys, habitat improvement works and little penguin research programs.

Nocturnal Tours

South of Perth, Western Australia, visitors to Penguin Island are able to view penguins in a natural environment. 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, Victoria, a viewing area has been established 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 or film the birds (this is because it can blind or scare them) interacting in their colony.^[67]

In Otago, New Zealand town of Oamaru, where visitors may view the birds returning to their colony at dusk.^[68] 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 established 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.^[69]

Visitors to Kangaroo Island, South Australia, have nightly opportunities to observe penguins at the Kangaroo Island Marine Centre in Kingscote and at the Penneshaw Penguin Centre.^[70] Granite Island at Victor Harbor, South Australia continues to offer guided tours at dusk, despite its colony dropping from thousands in the 1990s to dozens in 2014.^[71] There is also a Penguin Centre located on the island where the penguins can be viewed in captivity.^[72]

In Bicheno, Tasmania, evening penguin viewing tours are offered by a local tour operator at a rookery on private land.^[73]

Habitat restoration

Several efforts have been made to improve breeding sites on Kangaroo Island, including augmenting habitat with artificial burrows and revegetation work. The Knox School's habitat restoration efforts were filmed and broadcast in 2008 by Totally Wild.

Zoological exhibits

Australia

Exhibits currently exist at the Adelaide Zoo, Melbourne Zoo, the National Zoo & Aquarium in Canberra, Perth Zoo and the Taronga Zoo in Sydney.^{[74][75][76][77][78]}

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.^[79][80][81] 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.^[82] A new enclosure for the little penguin colony was opened at Sea World in 2008.

New Zealand

Exhibits currently exist at the Auckland Zoo, the Wellington Zoo and the National Aquarium of New Zealand.^[83]

North America

A colony of little blue penguins exists at the New England Aquarium in Boston, Massachusetts. The penguins are one of three species on exhibit and are part of the Association of Zoos and Aquariums' Species Survival Plan for little blue penguins.^[84]

	Little penguins in the wild calling, Dunedin, New Zealand
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	Little penguin calls at the St Kilda Breakwater, Victoria, Australia
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Mascots & 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.^[85]

A Linux kernel programming challenge called the Eudyptula Challenge^[86] has attracted thousands of persons; its creator(s) use the name "Little Penguin".

Penny the Little Penguin was the mascot for the 2007 FINA World Swimming Championships held in Melbourne, Victoria.^[87][88]

See also

• Animals portal

References

Further reading

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

External links

Wikispecies has information related to: Eudyptula minor

Wikimedia Commons has media related to Eudyptula minor.

• 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. 

Penguins (order: Sphenisciformes · family: Spheniscidae · subfamily: Spheniscinae) Genus Species Aptenodytes (great penguins) King penguin Emperor penguin Pygoscelis (brush-tailed penguins) Adelie penguin Chinstrap penguin Gentoo penguin Eudyptula (little penguins) Little penguin (or little blue penguin) White-flippered penguin (or northern little penguin) Spheniscus (banded penguins) Magellanic penguin Humboldt penguin Galapagos penguin African penguin Megadyptes Yellow-eyed penguin Waitaha penguin (extinct) Eudyptes (crested penguins) Fiordland penguin Snares penguin Erect-crested penguin Southern rockhopper penguin Northern rockhopper penguin Royal penguin Macaroni penguin Chatham Islands penguin (extinct)