Species

Magellanic penguin

June 7, 2012, 4:57 pm
Content Cover Image

Magellanic penguin colony, Otway Sound, Chile. @ C.Michael Hogan

The Magellanic penguin (Spheniscus magellanicus) is one of seventeen species of flightless birds in the family Spheniscidae (or 'modern penguins'). It is one of four "Banded Penguins" in the genus Spheniscus which also includes the Black-footed, Humboldt, and Galapagos penguins.

 

caption Source Jim Ross/BioLib/Encyclopedia of Life

 

Conservation Status

 

Scientific Classification

Kingdom: Animalia
Phylum:--- Chordata
Class:------ Aves
Order:-------- Sphenisciformes
Family:-------- Spheniscidae (Penguins)
Genus:--------- Spheniscus (Banded Penguins)
Species:-------- Spheniscus magellanicus (Forster, 1781)

Like all penguins, the Magellanic penguin is distinguished by an erect posture, stiff wings (flippers), outstanding swimming capability, awkward movement on land and bold plumage marking. The Magellanic's black back and white front make it difficult to see when swimming, blending with the sea when viewed from above, and blending with the sky when viewed from the underwater realm below. 

Physical Description

Magellanic Penguins are medium sized penguins. Their average length is 70 cm (27.5 in) and weight ranges from 3.8 kg-6.5 kg (8.25 lb-14.25 lb). Males and females are similar in appearance, but males are usually larger. Physically, they have a fairly large head with a short neck. Tails are short and wedge shaped, and wings are elongated with a fused wrist joint, that denies flexing (Lynch. 1997) but allows for strength and rigidity in the water but sacrifices the folding of wings of other birds; this wing architecture enhances swimming strength, that is also abetted by the species' webbed feet; moreover, the feet are set far back on the body, which gives this penguin an upright stance when terrestrial. Like most penguins, they exhibit counter-shading (i.e. dark brown or black colored dorsal side and a silvery white colored ventral side). This is both for camouflage for hunting its prey as well as a defense from predators. Most Magellanic penguins have a white band on both sides of the head, which begins at the eye and joins at the neck, while there is a dark brown horseshoe mark on the underside, running down the flank of the body and contrasting with the otherwise white underparts.

Behavior

 

caption Ragged look of the Magellanic penguin during moulting at the end of breeding season, Otway Sound, Chile. Source: C. Michael Hogan

 

Magellanic penguin colonies can be quite old. One colony in Punta Tomba, Argentina is estimated to have been used for at least 114 years as the breeding ground for at least a million Magellanic penguins. They live in the company of Rockhopper and Gentoo penguins, but are relatively shy compared to both Rockhoppers.and Gentoo.  Depending on location, the habitat preference and temperament of S. spheniscus is variable. Most Magellanic penguins prefer to live in large, densely packed colonies. Some may be widely scattered and live in isolated groups with four or five pairs nesting. Both males and females fight over nesting sites, but fights are more common between two males. Most fights last only one minute and usually resolve with one bird chasing away the other. The male uses donkey-bray sounds to attract a female to the nesting site;  pairs characteristically click their bill tips together in a courtship ritual (Hogan, 2008)

Reproduction

Breeding season is in September to early October and again in January through February. Male and female penguins make nests where soil has little sand and high clay content, in either underground burrows they dig themselves or on the surface. These nests are big enough for both adults and can sometimes be deep.The nesting season may be split into an early and later component. (Müller-Schwarze. 1984)

The male transfers sperm into the female through the cloaca. Female penguins lay two eggs which are off white in color with red and green stains from the bile and blood. The surface texture is chalky, but smooth. Eggs can weigh 115 g-145 g (0.25 lb-0.32 lb), and may take 39-42 days to hatch.

Both parents share incubation process and duties. Once chicks are born, they are guarded by both parents for 29 days and then left unattended for approximately 40-70 days. Parents alternate guarding and feeding responsibilities. Chicks are fed every 1-3 days by either parents, and as they get older, the time between feeding periods increase. Depending on food availability, chicks may fledge 60-120 days after hatching.

caption Part of the Otway Sound Magellanic colony preparing to go out to sea for the season, southern Chile. Source: C.Michael Hogan

 

Distribution

Magellanic Penguins are temperate weather penguins. The main breeding ranges are located in Cape Horn to 42° south on the Atlantic coast, Tierra del Fuego to 29° south on the Pacific coast, and the Falkland Islands. During winter season, the penguins from the Atlantic coast migrate to the coast of Brazil while the population from the Pacific Coast migrate north, to as far as Peru.

Habitat and feeding habit

Habitat can vary from bare to forested terrain, including relatively level scrub-covered coastal terraces and even cliff faces, using the local environment's vegetation to suit their needs. Typically, the Magellanic penguin chooses a soft sandy coastal soil for burrow construction for the sake of ease of excavation; however, the soils are generally composed of sufficient loam or clay to support the burrow integrity, and frequently these burrows are constructed in soils that have a robust coastal prairie plant association, whose root structures keep the surface soils intact and enhance the burrow stability.

Magellanic Penguins usually hunt for food in groups, diving six to 90 m beneath the ocean surface. They are carnivorous in nature, and their diet includes squid, fish, crustaceans, and krill.

caption Part of the Otway Sound Magellanic colony preparing to go out to sea for the season, southern Chile. Source: C.Michael Hogan

 

Conservation Status

According to the IUCN Red List, the Magellanic penguin is classified Near Vulnerable, with a population stated to be declining. (IUCN. 2009)  Since the year 1987, the Magellanic penguin population has declined by approximately twenty percent globally. Study sites reveal Magellanic penguins throughout the Falklands have declined seventy percent in the last decade, a trend that persists at present. However, there is no sign of decline in the South American breeding colonies.

Economic Importance for Humans

Magellanic penguin colonies are a tourist attraction in parts of the Falkland Islands, Patagonia and certain other locations.

Reference sources

Glossary

Citation

Life, E. (2012). Magellanic penguin. Retrieved from http://www.eoearth.org/view/article/154354

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