Penguins are threatened by climate change . Penguin populations have decreased by nearly 80 percent in some areas, and the majority of scientists agree that rising temperature due to climate change is the primary culprit.
In Antarctica, home to the famous emperor penguin, the annual sea ice melting season has extended by as much as 3 weeks in recent decades. Less ice means less habitat for penguins and the loss of critical food, such as shrimp-like krill, which depend on polar ice to reproduce.
The penguin that is currently most threatened by climate change is the African penguin. Most African penguins live on islands off the coast of Africa and feed on a rich supply of anchovies and sardines that follow a nearby current of cold water. As the oceans heat up, this stream is moving further away from their island home. These penguins will only swim up to 25 miles away from their homes, so if the current moves much further they will not be able to reach their food source.
In addition to global warming and natural predation by sharks, orcas, leopard seals, sea lions and fur seals, other threats to penguins include impacts on habitat  due to oil spills, pesticides, construction, destruction of habitat due to introduced herbivores, competition with humans for food and illegal egg harvesting.