Penguins are a group of aquatic flightless birds. They live almost exclusively in the southern hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adapted for life in the water, penguins have countershaded dark and white plumage and flippers for swimming. Most penguins feed on krill, fish, squid and other forms of sea life which they catch while swimming underwater. They spend roughly half of their lives on land and the other half in the sea.
The largest living species is the Emperor Penguin (Aptenodytes forsteri), which is the tallest and heaviest of all living penguin species and is endemic to Antarctica. The male and female are similar in plumage and size, reaching 39 inches in length and weighing from 49 to 99 lb.
Like all penguins it is flightless, with a streamlined body, and wings stiffened and flattened into flippers for a marine habitat. Its diet consists primarily of fish, but also includes crustaceans, such as krill, and cephalopods, such as squid. While hunting, the species can remain submerged around 20 minutes, diving to a depth of 1,755 ft.
Emperor penguins trek 31–75 miles over the ice to breeding colonies which can contain up to several thousand individuals. The lifespan is typically 20 years in the wild, although observations suggest that some individuals may live to 50 years of age.
Why They Matter
Penguins play important roles in ecosystems both in the ocean and on land. Penguins — adults, young and eggs — serve as food for predators such as leopard seals and seabirds in cold areas, along with foxes, leopards, and even crabs in warmer climates. By chasing after fish, squid and krill, they affect prey populations wherever they hunt. They carry nutrients between land and sea, and enrich both with their feces. Some burrowing species even modify the landscape as they dig nests into the ground organisms.
As keystone species, they help maintain biodiversity of the ecosystems they inhabit.
In 2012 the emperor penguin was uplisted from a species of least concern to Near Threatened by the IUCN. Along with nine other species of penguin, it is currently under consideration for inclusion under the US Endangered Species Act.
The primary causes for an increased risk of species endangerment are declining food availability, due to the effects of climate change and industrial fisheries on the crustacean and fish populations. Other reasons for the species's placement on the Endangered Species Act's list include disease, habitat destruction, and disturbance at breeding colonies by humans. Of particular concern is the impact of tourism.