Penguin of the Week: Little

The world’s smallest penguin (also known as Little Blue, Blue and Fairy Penguin).

The Little Penguin closely resembles juveniles of the genus Spheniscus, but their ranges do not overlap. Upper parts are pale blue to a dark grey-blue depending upon age, season and subspecies. The transition from the dark upper parts to the white plumage of the lower body is not as well defined as in other penguins, going through shades of grey and brown, especially in the face.

In contrast to the other species, Little Penguins are nocturnal. That means they generally do not enter the shore before dusk and leave it before dawn. They forage during the day and often will sleep beside the nest at night after they have fed chicks. This species nests in burrows, under trees, in rock crevices, and sometimes in caves. Usually nests are clustered to form colonies, but single breeding pairs are not uncommon. At sea Little Penguins are often found alone or in small groups of up to ten birds, but sometimes these groups can be much larger. Although foraging trip durations can be highly variable, Little Penguins tend to stay close to the coast.

Little Penguins are widely distributed in Australia (from Western Australia along the southern coast of Australia up to New South Wales) and in New Zealand (from Northland to Stewart Island and the Chatham Islands). The White-flippered Penguin (E. m. albosignata) is an endangered subspecies, restricted to Banks Peninsula and Motonau Island (South Island, New Zealand) that has often been treated as a full species. Geographic variation of size, extent of white on the tail and flipper, and colour tone of the back is considerable. Six subspecies have been described: novaehollandia in Australia, iredaei in northern New Zealand, variabilis from Cook Strait, New Zealand, albosignata on Banks Peninsula, minor in the lower part of the South Island, New Zealand, and chathamensis from the Chatham Islands.

Penguin of the Week: Yellow Eyed

The Yellow-eyed Penguin (Megadyptes antipodes) or Hoiho is a penguin found in New Zealand, on the south-east coast of South Island, Foveaux Strait and Stewart Island/Rakiura, and Auckland and Campbell Islands.

This is a fairly large penguin, averaging 75 cm (30 in) long and weighing about 6.3 kg (14 lbs). It has a pale yellow head and paler yellow eyes with black feather shafts. There is a band of bright yellow running from its eyes around the back of the head. The juvenile has a greyer head with no band and their eyes have a grey iris.

This penguin usually nests in forest or scrub. It feeds mainly on blue cod, red cod, opalfish, sprat and squid.

The current status of this penguin is endangered, with an estimated population of 4,000. It is considered one of the world’s rarest penguin species. The main threats include habitat degradation, introduced predators as well as environmental changes. It is thought to be the most ancient of all living penguins[citation needed].

In spring 2004, a previously undescribed disease killed off 60% of Yellow-eyed penguin chicks on the Otago peninsula and in North Otago. The disease has been linked to an infection of corynebacterium, a family of bacteria that also causes diphtheria in humans. It has recently been described as diphtheritic stomatitis. However, it seems as if this is just a secondary infection. The primary pathogen remains unknown.

Several mainland habitats have hides and are relatively easily accessible for those wishing to watch the birds come ashore. These include beaches at Oamaru, Moeraki light-house, a number of beaches near Dunedin, and The Catlins. In addition commercial tourist operations on Otago Peninsula also provide hides to view yellow-eyed penguins.

Penguin of the Week: Magellanic

Magellanic penguins are only found around the Falkland Islands and South America, but they are extremely numerous within these regions. The Falklands has a population well in excess of 100,000 breeding pairs, but this is small compared to populations in South America, which number around 900,000 breeding pairs in Argentina (Centro Nacional Patagónico) and 800,000 pairs in Chile (Environmental Research Unit). Breeding colonies range from the Golfo San Matías in Argentina, southwards around the islands of Tierra del Fuego, and northwards up the Pacific coast of Chile as far as Puerto Montt.

The Magellanic penguin is around 70cm long, and has an average weight of about 4kg. The head and upper parts are black apart from two broad white stripes beneath the throat; one running up behind the cheeks and above the eye to join the pinkish gape, the second running adjacent to the white underparts with which they merge above the legs. Females are slightly smaller than the males, but have similar plumage.

Penguins of the Genus Spheniscus, to which Magellanic, Humboldt and Galapagos penguins all belong, are much more loosely colonial than other penguins. They generally nest in burrows when soil conditions permit, and are consequently spaced much further apart than surface-nesting penguins. Magellanic penguin colonies in particular often extend over several kilometres of coastline, at densities ranging from 0.001 to 0.1 nests per sq.m.

Magellanic penguins are widely distributed throughout the region. They particularly like offshore islands with tussac grass or small shrubs, which are in abundance around the Falkland Islands, Tierra del Fuego and the Pacific coast of Chile. Such islands offer deep layers of soil for burrowing into, and dense vegetation offering protection from aerial predators. The Atlantic coast of mainland Argentina is much drier, and has less vegetation cover, but it is still home to around 650,000 breeding pairs, many of which nest above ground in surface scrapes or under bushes. Magellanic Penguins prefer to nest in burrows, but when soil conditions are unsuitable for burrowing, they will nest on the surface using whatever protection they can find.

Penguin of the Week: Humboldt

Endemic to the cold nutrient-rich waters of the Peru Current, the Humboldt Penguin breeds in a hot Mediterranean to desert climate. Populations fluctuate under the influence of El Niño events, which can cause significant breeding failure and adult starvation.

Similar to Magellanic Penguins, but lacks the second dark breast band and has a wider white band around the head. Humboldt Penguins also have more extensive areas of bare skin than Magellanic Penguins, including a pink fleshy patch at the base of the lower mandible. Immature birds are very similar to those of Magellanic Penguins but are generally darker on the head.

Humboldt Penguins nest in burrows - often dug into thick guano deposits, among boulders, in sea caves and sometimes in the open. Most birds depart the colony after sunrise and forage in close proximity to the colony. Foraging distances vary with location but Humboldt Penguins are typically inshore foragers. They are gregarious in the breeding colonies but are less so at sea.
Captive birds moult once a year.

Endemic to the Humboldt Current, breeding range extending from 5° S in Peru to 37°S in Chile, with isolated colonies existing as far as 42°S near Puerto Montt.

Penguin of the Week: Galapagos

The Galápagos Penguin (Spheniscus mendiculus) is a penguin endemic to the Galápagos Islands. It is the only penguin to live on the equator and can survive due to the cool temperatures resulting from the Humboldt Current and cool waters from great depths brought up by the Cromwell Current. Its nearest relatives are the African Penguin, the Magellanic Penguin and the Humboldt Penguin. The Galápagos Penguin occurs primarily on Fernandina Island and the west coast of Isabela Island, but small populations are scattered on other islands in the Galápagos archipelago.

Galápagos Penguins grow to between 48-53 cm tall. They have a black head with a white border running from behind the eye, around the black ear-coverts and chin, to join on the throat. They have blackish-grey upperparts and whitish underparts, with two black bands across the breast, the lower band extending down the flanks to the thigh. Juveniles differ in having a wholly dark head, greyer on side and chin, and no breast-band.

The Galápagos Penguin mates for life. It lays one or two eggs in places such as caves and crevices, protected from direct sunlight, which can lead to the eggs overheating. One parent will always stay with the eggs or chicks while the other is absent for several days to feed. If there is not enough food available, the nest may be abandoned.

The species is endangered, with an estimated population size of around 1,500 individuals in 2004, according to a survey by the Charles Darwin Research Station. The population underwent an alarming decline of 65% in the 1980s, but is slowly recovering. It is therefore the rarest penguin species (a status which is often falsely attributed to the Yellow-eyed penguin). Population levels are influenced by the effects of the El Niño Southern Oscillation, which reduces the availability of shoaling fish, leading to low reproduction or starvation. However, anthropogenic factors (e.g. oil pollution, fishing by-catch and competition) may be adding to the ongoing demise of this species. On Isabela Island, the introduced cats, dogs and rats may attack penguins and destroy their nests.