Emperor penguins – There are 17 species of penguin, with emperor penguins being the largest. They weigh up to 45 kilos (100 pounds) and grow to 120 centimeters (48 inches) tall. These three are pictured on sea ice at McMurdo Sound in Antarctica.
Where to spot them – Emperors can be seen along the coast of Antarctica. Breeding colonies are often the destination for cruises and scenic flights. Penguin species can also be spotted in South Africa, Chile, Argentina, Australia and New Zealand.
Climate change – As with most polar species, penguins are feeling the effects of climate change. Ice melt is changing their breeding grounds and overfishing and ocean acidification is affecting their food sources of fish, squid and krill.
That waddle – Emperors have an awkward, waddling gait on land, but are graceful in the water. These birds can dive more than 550 meters (1,800 feet) and stay under for up to 20 minutes.
Adelie penguins – Less than half the size of an emperor penguin, Adelie penguins are one of the smallest of the Antarctic penguin species. Each October, they build nests of rocks on land near open water.
Strength in numbers – Adelies are one of the most abundant of the penguin species. They can be found in large colonies and on icebergs and coastal areas in Antarctica waters.
Reduced habitat – Adelie penguins face the same climate change dangers as emperors, such as reduced habitat and a diminishing food supply. However, due to their larger population, they're currently less at risk.
South polar skua – The south polar skua is the Adelie's only land predator. It will attempt to steal penguin eggs and attack young chicks. Penguins work together to fight off the vicious skuas.
African penguin – The warmer climes of coastal South Africa and Namibia are home to the African or jackass penguin. Boulders Beach near Cape Town, South Africa, is a popular destination for penguin spotting.
Homebodies – Unlike the highly mobile penguins in Antarctica, African penguins breed, nest and feed in the same area instead of traveling hundreds of miles between sites. They build nests under boulders or bushes or burrows dug from their own guano.
Endangered species – African penguins are listed as an endangered species. Their decreasing population is spurred by loss of nesting grounds due to guano removal by humans, as well as a decreasing food supply as a result of overfishing.
Little penguins – The little penguin, also known as the fairy or blue penguin, can be found on the coasts of New Zealand and southern Australia. They're the smallest of all penguins, weighing just a kilo or two and topping out at just over 30 centimeters tall.