Penguins waddle around in ungainly fashion on ground, but once in water they transform into expert swimmers and can cruise at speeds of 15 miles per hour. Although the penguin is a bird species, they are unable to fly because they have flippers instead of wings. The penguin's black body and white belly is an excellent aquatic camouflage when it sets out to hunt for food, which mainly consists of fish, crabs, squid and shrimps.

Penguins are essentially an inhabitant of the Southern Hemisphere and are the only distinctive creatures of the icy Antarctic continent, or South Polar region, where nearly two-thirds of the world's penguins are found. Antarctica is home to two major species of penguins, the emperor penguin and the Adele penguin. As many as 16 species are to be found in coastal Chile, southern parts of South America, the south-western coast of RSA (Republic of South Africa), southern coastal fringes of Australia, Tasmania, New Zealand and the numerous islands and archipelagos dotting the southern Indian Ocean and south Atlantic and South-Eastern Pacific.

All 18 species of penguins fall in the endangered category and their populations could shrink by almost a fifth in the decades to come. Despite the Antarctic Treaty signed by 12 nations ensuring the protection of the species, major threats to their survival continue to exist.

Climate change in the form of melting of Antarctic ice and warming of waters is affecting food sources of emperor penguins. Organisms like zooplankton and phytoplankton grow only on thick ice. These are food for fish, squid and krill which in turn supplies a major part of the penguin's diet.  African penguins, especially, are the most vulnerable to climate change. Many of them are found on the islands off the coast of South-Western Africa and feed on a rich diet of sardines and anchovies that come in with the cold Benguela current. Heating oceans are causing this current to move further from its normal path, making the search for food for the penguins a much more difficult task. The penguins swimming reach is only up to 25 kilometers at the most.

Oil and gas exploration activities, and their resultant spill-outs, have destroyed large swathes of the penguins' food territory leading to outright starvation. There have been instances of penguins drenched in oil, making it difficult for them to stay afloat. Ingestion of toxic chemicals from exploration activities have resulted in deaths and severe drops in body temperatures or hypothermia. A major oil spill off Nightingale Island in the South Atlantic ocean resulted in the deaths of 200,000 Rockhopper penguins, half the world's population of this species.

Overfishing by an avaricious commercial-minded industry has resulted in a major depletion of fish stocks on which penguins feed. The penguin's inability to swim very far can result in it coming back to its nesting site with nothing to feed its offspring.

Although penguin hunting and egg harvesting is now illegal, it continues to occur. Legal harvesting of penguin guano to be used as fertilizer also endangers some penguins, as guano is essential for their nesting burrows.

Yet another threat to penguins is habitat destruction. Tourism-related pressures, such as foot traffic and litter, is encroaching on penguin colonies and nesting sites. 

Penguins have always faced natural predators, but they are now threatened with new introduced predators. Feral dogs, cats, rats and ferrets steal their eggs. Penguins usually live in specific areas and return to specific mating areas, making it easy for introduced predators to severely decrease their populations.

One of the most endangered penguin species is the little blue penguin found in Australia, New Zealand, Chile and parts of the Tasmanian coast. They are the smallest species of penguins and stand just over a foot in height. They have an average lifespan of 5-6 years, compared to the penguin average of 15-20 years. As this small creature does not breed until almost 3 years of age, reproduction is a serious issue for this species. Despite being protected by stringent laws from illegal hunting, threats from predators always exist. It is prey for sharks, seals and weasels in the waters, and for snakes and foxes when on land.

Other larger species of penguins are favorite prey of the killer whale, skua (a large sea bird), and the leopard seal of the Western Antarctic where concentrations of the emperor and Adele penguins are high.

Fundamental changes are needed if we are going to save this iconic creature of the Southern Hemisphere. Habitat loss, pollution, and fishing, all factors humans can readily mitigate, remain the primary threats for penguin species. Their future resilience to further climate change impacts will almost certainly depend on addressing current threats to existing habitat degradation on land and at sea. Protection of breeding habitat and designation of marine reserves is critical for the future conservation of penguins. Other ecosystem-based management methods must also be developed to maintain marine biodiversity and ensure that ecosystem functioning is maintained across a variety of scales.