When fully developed, they are approximately 23-27 inches long and weigh between four and nine pounds. These penguins have black backs, faces, wings, feet and beaks. The front of their torsos are white with some black spots and a black stripe across their chests. White stripes run around their faces to above their eyes. Juveniles have slate gray backs and lack the facial pattern that the adults have. 

African penguins can remain underwater for more than 2 ½ minutes. They conserve energy while swimming by “porpoising” (alternating between jumping out of the water and swimming). A hunting group may venture 30 miles or more from the nest colony and spend several days at sea in search of food.

once a year. Feathers need to be replaced because they wear out. The feathers need to be in good condition as they are responsible for the penguin's waterproofing and insulation. During the year, penguins – like other birds – clean and arrange the feathers using oil from their preen gland. Unlike other bird species, penguins molt all of their feathers over a very short period of time (usually 15 to 20 days).

The new feathers grow under the old ones, and push the old feathers out. During the molt, large patches of feathers are pushed out by the new feathers. This is a big energy drain and the birds will look uncomfortable and scruffy. During this period penguins stay out of the water for the most part. The partially molted feathers no longer provide insulation and waterproofing.

Prior to molt, penguins build up a large layer of fat to provide energy for the molt as they cannot go into the water and feed. In captivity, penguins may eat a few fish while they are molting, because they do not have to go into the water to eat.  

typically in four years.  They breed in nesting colonies usually found on coastal islands or select mainland beaches where they dig shallow burrows under rocks, in sand, or under sparse vegetation. In the past, birds dug burrows in their own “guano” (bird excrement), but this has been mined extensively and there is little left to nest in. African penguins are monogamous, breeding with the same mate and generally returning to the same nesting colony year after year. The pair bond is reaffirmed at the nest colony. 

African penguins can breed at anytime of the year, with the peak breeding season varying with location. In the Northwest, peak egg laying occurs in Nov/Jan; in the Southwest in May/June and in the East in Apr/June. African penguins normally lay two eggs; the incubation period is 38-40 days and the parents share equally in attending to the nest. The chick will remain in the nest for 30 days,  after which the parents both go to sea to gather food and the chick is left at the colony. The chicks may form small crèches or remain alone until the parents return with food. Depending on the availability of food, the chick’s downy feathers will be replaced with juvenile plumage at 60-130 days. Shortly after the juvenile plumage is attained, the adults abandon the chicks and the juvenile birds are left to learn how to forage and avoid predators on their own – this is one reason juvenile mortality is high.

variations in temperature. Like all other penguins, they have a thick layer of fat under their skin and more densely packed feathers compared to other birds groups. Penguins, like all other birds, preen themselves using oily secretions to “waterproof” their feathers and help protect the penguins in cold water. These adaptations help prevent heat loss while swimming in near-freezing water.

While on land, unlike Antarctic species of penguins, African penguins have to contend with warm temperate conditions when they emerge from the water. They may experience a sudden temperature shift of more than 70 degrees Fahrenheit. or more.  African penguins avoid overheating by breathing through their mouths, exposing their feet, and lifting their feathers - a process known as "bristling." The birds avoid standing in the sun and spend the day time hours either foraging at sea, or in burrows on land.

penguins at the beginning of the 20th century; today, approximately 25,000 pairs of birds remain (an 80 percent decline in the past 50 years). Early declines to the penguin population included a major oil spill in 2000 and guano harvesting. The species is now listed as “endangered” under the U.S. Endangered Species Act and the International Union for Conservation of Nature (IUCN) Red List of Threatened Species.

Many issues threaten penguin populations: over-fishing, pollution, oil spills, fluctuating temperatures, lack of sun protection, predation by Cape fur seals and sharks, predation of eggs and chicks by domestic cats and dogs, and habitat loss. Recent studies have found that the African penguin population's ability to rebound after decades of loss is directly linked to the decline of a very nutritional food source: sardines. Anchovies and other fish do not provide the high level of nutrition the penguins need. The collapse of the sardine fisheries in the last part of the 20th century is a major limiting factor in the penguins’ recovery. Conservation groups have become very effective in rescuing “oiled penguins” and deserted penguin chicks and returning them to the wild.

There are 6 genera and 17 species of extant (living) penguins and the African penguin is the only penguin native to Africa. It is the only order in Aves (birds) in which all the members are both flightless and aquatic. The African penguin has a very distinct mating call, resembling the sound of a donkey. Hence, this penguin species is often referred to as the “jackass penguin.”