Friday, May 1, 2009

Spheniscus magellanicus--Magellanic Penguin











Spheniscus magellanicus---Magellanic Penguin
By Caleb Wong

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Aves
Order: Sphenisciformes
Family: Spheniscidae
Genus: Spheniscus
Species:
Geographic Range

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.

(Lynch 1997, Todd 1981)

Biogeographic Regions:

neotropical (native ); atlantic ocean (native ); pacific ocean (native ).

Habitat

Depth
onshore to 90 m(to 295.2 ft)

Habitat can vary from bare to forested terrain, flat land, cliff faces, and coasts, using the environment's vegetation to suit their needs.

(Williams 1995)

These animals are found in the following types of habitat:
temperate ; terrestrial ; saltwater or marine .

Terrestrial Biomes:
forest .

Aquatic Biomes:
coastal .

Physical Description
Mass
3800 to 6500 g; avg. 5150 g
(133.76 to 228.8 oz; avg. 181.28 oz)

Length
70 cm (average)
(27.56 in)

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 long and narrow with a fused wrist joint which allows for strength and rigidity in the water but sacrifices the folding of wings that other birds are capable of. Webbed feet are set far back in the body, which gives them an upright stance when standing on land. Like most penguins, they exhibit counter shading - i.e. a dark brown or black colored dorsal side (back) and a silvery white collored ventral side (belly). This is both for camouflage for hunting its prey as well as a defense from the Magellanic Penguins' predators. Most Magellanic Penguins have a white band on both sides of the head, which begins at the eye and joins at the neck, and another white band, which joins below the throat, and runs down the side of the body. (Lynch, 1997; William, 1995)

Some key physical features:
endothermic ; bilateral symmetry .

Reproduction
Time to hatching
40 days (average)
[External Source: AnAge]

Age at sexual or reproductive maturity (female)
1040 days (average)
[External Source: AnAge]

Age at sexual or reproductive maturity (male)
1040 days (average)
[External Source: AnAge]

Breeding season is in September to early October and again in uary 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 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 responsibilties. 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.

(Todd 1981, William 1995)

Key reproductive features:

iteroparous ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous .

Behavior

Magellanic penguin colonies can be quite old. One colony in Punta Tomba, Argentina is estimated to be at least 114 years old, and home for at least million birds. They live in the company of Rockhopper and Gentoo penguins, but are relatively shy compared to Rockhoppers. Depending on where they live, habitat preference and temperament can be variable. Most Magellanic penguins prefer to live in large, densely packed colonies. Some may be wildly 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 1 min and usually ends with one bird chasing away the other. Males use sounds ('donkey-bray') to attract females to their nesting site. Pairs hit their bill tips against each other to represent courtship.

(Lynch 1997, Todd 1981, William 1995)

Key behaviors:

motile .
Food Habits

Magellanic Penguins usually hunt for food in groups, diving 6 m-90 m underwater. They are carnivorous in nature, and their diet includes squid, fish, crustaceans, and krill.

(Lynch 1997, William 1995)
Economic Importance for Humans: Positive

Penguin colonies are a tourist attraction in the Falkland Islands.
Conservation Status

IUCN Red List:
Near Threatened.

US Federal List:
No special status.

CITES:
No special status.

Since 1987, the Magellanic penguin population has declined by 20% globally. Study sites reveal Magellanic penguins throughout the Falklands have declined 70% in the last 10 years, a process that is still occurring. However, there is no sign of decline in South America (Lynch 1997, Falklands Wildlife Newsletter).
Contributors

Caleb Wong (author), Fresno City College.
Carl Johansson (editor), Fresno City College.
References

"Falklands Wildlife Newsletter" (On-line). Accessed (Date Unknown) at http://www.seabirds.org/news.

Lynch, W. 1997. Penguins of the World. Willowdale, Ont.: Firefly Books.

Todd, F. 1981. The Sea World Book of Penguins. San Diego, California: Sea World Press.

William, T. 1995. The Penguins. Oxford, New York: Oxford University Press.
2009/04/26 05:02:26.211 GMT-4

Sources:
Wong, C. 2001. "Spheniscus magellanicus" (On-line), Animal Diversity Web. Accessed May 01, 2009 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Spheniscus_magellanicus.html.
Images courtesy of ARKive

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