Common Name: Magellanic penguin
Species Name: Spheniscus magellanicus
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.
Measurements : 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.
Breeding Biology : Breeding biology information is from Punta Tombo (Boersma unpublished data); each Magellanic penguin colony will differ.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.
Prey: 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).
Predators : 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.
For more information on the penguins, threats, and conservation pick up a copy of
Penguins: Natural History and Conservation by Dr. Pablo Garcia Borboroglu and Dr. P. Dee Boersma