The Biotic Factors Affecting African Penguins

Diet

• African penguins are carnivores and their diet consists mainly of fish found in the waters off the coast of South Africa. African penguins feed primarily on anchovies, sardines, herring, squid and crustaceans. Changes in ocean temperature during the first decade of the 21st century have caused a reduction in the number of pelagic fish -- open water schools such as herring and sardines -- that African penguins feed on. This food shortage is causing smaller African penguin populations each year, as there is not enough food to support all of the hatchlings born during breeding season.

Predators

• Another biotic factor that affects African penguins is the presence of natural predators. Cape fur seals prey on the penguins themselves but also compete with them for small fish and territory. Some colonies of African penguins are preyed upon by feral cats, and many eggs and hatchlings are vulnerable to avian predators such as kelp gulls and sacred ibises. Mongooses and leopards are frequent predators of the African penguin on land, and great white sharks and killer whales hunt them at sea.

Breeding

• The behavior of other African penguins, such as their mates and parents, also affects the birds' life cycle. African penguins are monogamous and most mating pairs meet year after year, often in the same location. After hatching an egg both, parents take turns watching the chick for its first month. Soon the chicks are left to fend for themselves while parents hunt for food. Parents who cannot find enough food, or leave their chicks vulnerable to predators for too long, often return to find dead offspring.

Human Impact

• Human activities also greatly affect African penguins. The species is endangered and is expected to be extinct within the next 15 years, according to the South Africa Foundation for the Conservation of Coastal Birds. Overfishing of pelagic fish by humans is depleting the African penguins' primary food source. Pollution poses another risk as the African penguins habitat lies on a major oil shipping route. Conservationists fear one oil spill could wipe the species out. Not all the biotic factors surrounding humans are negative. Some environmentalists hand-raise penguin chicks and release them into the wild to bolster the dwindling population.