Magellanic Penguin

Magellanic Penguin


Status (IUCN v3.1)
This species has fluctuated in numbers in different parts of its range, but overall moderately rapid declines are thought to have been sustained and as a result it is listed as Near Threatened.

Conservation Concerns
The Magellanic Penguin Project is a joint project with the Wildlife Conservation Society, the Province of Chubut, and the University of Washington that was launched in 1982 when a Japanese Company sought a concession to harvest Magellanic penguins in Argentina. The project trains the next generation of conservation biologists, gathers the scientific information to inform decision-makers and helps in protection and management of Magellanic penguin colonies. Penguins are incredible creatures swimming as much as 170 km in a day and traveling at the same speed, during the day and night, as they rush to their nests to feed their chicks. You can read more about penguins in Boersma 2008: BioScience.

Illegal ballast water dumping: In the 1980′s and early 1990′s approximately 20,000 adults and 22,000 juveniles died each year from oil pollution caused by illegally dumped ballast water. As a result of public concern and conservationists the provincial government of chubut moved tanker lanes 40km farther off shore in 1997 greatly reducing the number of oiled penguins each year. There are still a large number of penguins being oiled in northern Argentina, Uruguay, and southern Brazil where the penguins spend their winter.

Fisheries: Penguins are caught and killed in fishing nets and compete for the same limited resources as the fishing industry. Humans consume a large amount of small fish (the same species that penguins prey upon) reducing prey availability and likely causing penguin population decline.

Tourism: The increasing number of tourists may pose a serious risk to penguins either by disrupting their ability to return to their nests and feed their chicks or through stress that may result in slower growth of chicks and more exposure to predators.

Climate change: As a result of climate change and ocean variability, penguins now have to travel further to find prey.  Swimming further means their mates left at the nest must fast longer increasing the chances that the mates will abandon the nests and chicks will die of starvation.


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Punta Tombo Population Trend


Descriptive Characteristics
Adults have black backs and white fronts with two black bands on the neck. Their faces have a white crescent arching from their eye to their throat. Juveniles and chicks have one large band separating their face and their stomach. Their faces have cheek patches that range in color from white to dark grey.  Chicks go through two layers of down (hatching and cloverdown) before growing their juvenile plumage.


Penguin weights differ depending on time of season and how long each individual has been fasting. Generally, penguins will weigh their most when beginning the molt since they will need to fast for several weeks.

Generally, males are bigger than females.

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Breeding Biology
Breeding biology information is from Punta Tombo (Boersma unpublished data); each Magellanic penguin colony will differ.


Average Arrival Date: Early September
Average Egg Laying Date: October 18
Incubation Period: 40 – 42 days
Chick Rearing Period: 60 – 120 days
Fledging Period: January 10 to March 05
Average Annual Reproductive Success: 0.52 chicks/nest
Nest: Burrows, Bushes, Scrapes
Age at First Breeding: 4 years
Maximum Lifespan: 30+ years
Egg Weight:  124.8 (+/- 11.1) grams
Egg Length:  7.5 (+/- 0.3) cm
Egg Breadth:  5.5 (+/- 0.2) cm
Second Egg Weight:  124.4 (+/- 10.9) grams
Second Egg Length:  7.3 (+/- 0.3) cm
Second Egg Breadth:  5.6 (+/- 0.2) cm
Molt: Magellanic Penguins undergo an annual catastrophic molt during which they are confined to land and unable to replenish fat stores. Penguins must therefore begin the process at or above an appropriate body condition.  If penguins are too thin to complete the molt-fast when they arrive they will starve before returning to sea. However, if they return in too high of a condition they can succumb to heat stress in the Patagonian desert. Juvenile penguins begin molting in January, followed by young adults beginning their molt in late February, and finally older adults in late March. It takes approximately 19 days for an individual to complete molting.


Penguins prey upon anchovy (Engraulis anchoita), hake (Mercluccius hubbsi), Falkland sprat (Sprattus fueguenis), cod (Micromesistius australis), squid (Gonatus antarticus and Loligo gahi) and krill (Munida gregaria).

Kelp gulls, antartic skuas, little grison and large, hairy armidillos prey upon penguin eggs and small chicks. Red Foxes, grey foxes, pampas cat and pumas prey upon larger chicks, juveniles and adults on land. Giant petrels, south american sea lions, and orcas prey upon fledglings, juveniles and adults while at sea.