Emperor Penguin

Written By: Declan Richards, Biology 487, Winter 2009


Photo courtesy of National Science Foundation

Aptenodytes forsteri

Status (IUCN v3.1)
Least Concern

The emperor penguin has maintained a steady population trend over the last few years. The one concern that scientist have for the near future is the melting of ice caps which can prevent penguins from continuing to bread at their usual breeding grounds.

Conservation Concerns
Climate variation induced by CO2 emissions melts Antarctic ice and causes large pieces of the Antarctic ice shelf to break away. These icebergs get between the penguins and the ocean. During the winter the emperor penguins have evolved to survive to withstand temperatures as low as -40 degrees. Global warming is the most important threat that needs to be monitored, however many concerns are yet to be seen.

Currently, there is very little being done. It is very important to monitor the population trends to ensure the penguins continue to do as well as they have been.




Population Trend


Descriptive Characteristics
Adult plumage is characterized by its black and white pattern. The stomach is covered in white while the back is covered in black. The head has yellow patches around the eyes that have come to be called tear drops. Juvenile plumage looks like the adults’ with a slight grayish tone as well as they are a little paler around the eyes, chin and throat. Chicks are a silver down with a small black and white mask on the face.

Vocalizations: The Emperor penguins have a distinct trumpeting call that they use to communicate with their partners. They also have a high-pitched bray that is used in a powerful duet. At sea they use a loud “ah” sound to communicate.

There is very little sexual dimorphism found in the Emperor penguins. The males and the females will remain about the same size and will have similar plumage as adults.

Weight: 30 kg
Height: 115.0 cm
Beak: 8.0 cm
Flipper: 35.0 cm
Foot: 10.0 cm

Weight: 30 kg
Height: 115.0 cm
Beak: 8.0 cm
Flipper: 34.5 cm
Foot: 10.3 cm

Breeding Biology


Average Arrival Date: April
Average Egg Laying Date: May
Incubation Period:70 days
Chick Rearing Period: 150 days
Fledging Period: Late October to the end of December
Average Annual Reproductive Success: 1.00 chicks/nest; there is only one chick born to each breeding pair a year. The eggs are at most risk during the cold winter where temperatures reach well below freezing.
Nest: No Nest
Age at First Breeding: 5 years
Maximum Lifespan: 50 years
Egg Weight: 467 grams
Egg Length: 12.0 cm
Egg Breadth: 8.0 cm
Molt: The molt occurs during the month of January. The molt begins on the stomach of the penguin and then spreads around the rest of the body.

About 90% of the emperor penguins diet consists of fish. The rest is filled by small cepahlopods that the penguins find on the sea floor.

Once full grown the Emperor penguin has very few predators on land. Their main concern is to protect their chicks from the giant petrel. Once the penguins head to the sea their main predators are the leopard seal and the killer whale.