Animals Wildlife 12 Peculiar Penguin Facts By Starre Vartan Writer Columbia University Syracuse University Starre Vartan has been an environmental and science journalist for 15-plus years. She founded an award-winning eco-website and wrote a book on living green. our editorial process Starre Vartan Updated March 17, 2021 Digital Zoo / Getty Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species Penguins are flightless birds, but their wings are still very much a part of their mobility. Instead of gliding through the air, penguins use their wings — which evolved into flippers — to dive, cruise, and zoom through the water. They are athletic and dextrous swimmers, but walk with a waddle on land — where they spend 50% of their time — and use their tails for balance. The 18 (or 20) varieties of penguins have a lot in common, and for the most part are pretty similar, though some have special plumage, colors, and can vary in size, too. Read on to learn some peculiar and unexpected facts about penguins. 1. Penguins Only Live in the Southern Hemisphere Technically, one species of penguin lives in the Galapagos Islands, which straddle the Equator, so some Galapagos penguins may occasionally cross over into the Northern Hemisphere. Other than the occasional wanderer, all penguin species live in the Southern Hemisphere, where they seek colder waters. Even the Galapagos penguin stays in the Cromwell Current, a cold ocean current that hits certain areas of the islands. Penguins inhabit very cold regions, like the Antarctic, where we might be more used to seeing them. However, many penguin species live in temperate zones, like in Melbourne, Australia, where 1,400 fairy penguins live on St. Kilda's pier. The penguin colony there is so revered that volunteers are constantly present to keep people from getting too close. Fairy penguins are also known as little penguins, a very apt name for the smallest species of penguin. Besides Australia and neighboring New Zealand, penguins also live in Argentina, Chile, Namibia, South Africa, and even France (Ile aux Cochons, an island owned by France, to be precise). 2. There Are 18 (Or Maybe More) Species of Penguins There's some disagreement among scientists about how many penguin species there are. According to the IUCN Red List, there are 18 species of penguins, a recent update from the 17 previously recognized. The rockhopper penguin used to be considered one species, but in 2006, it was categorized as two separate species, the southern rockhopper penguin and the northern rockhopper penguin. These two species are now accepted by most scientists, but not all agree. And others think that a few other species of penguins should be divided into two species as well, so the number might be as high as 20 or 21 soon. 3. Penguins Have Feathers, Not Fur An adult king penguin molting on a snowy day on South Georgia Island. The old feathers are coming loose. Anne Dirkse / Getty Images One of the reasons penguins are able to survive in extremely cold environments is that they have feathers, not fur. Penguin feathers are so good at insulating the birds that overheating is actually more of an issue for them than keeping warm. Penguin feathers have some additional remarkable properties besides their amazing insulating capabilities. They are also icephobic, which means that they actually repel ice. That's why they can dive in and out of freezing water and get drenched by ocean waves, and not end up with icy patches on their feathers. Scientists who have studied the ice-repelling feathers believe that this feat is due to three characteristics: "a unique combination of the feather’s macroscopic structure, the nanoscale topography of its barbules, and the hydrophobicity of its preen oil." This means that the larger-scale and microscopic structure of the feathers, as well as a special oil secreted by the animal itself and distributed over its feathers, prevents ice from getting on them. As all birds do, penguins molt every year. Molting involves shedding old, worn feathers, and growing fresh new feathers. Penguins molt much more quickly than other birds though, in a 3- to 4-week process. Scientists have tracked king penguins due to their drastic molt, which involves them marooning on shore while they shed their feathers and fast. They lose half their bodyweight, including almost all of their fat and some muscle, which they must build back up once their feathers grow in. 4. Penguins Don't Have Teeth Mike Korostelev / Getty Just like their bird cousins, penguins don't have teeth. They do have spines inside their beaks, however, that can look a little tooth-like. They also have these spines on their tongues — both sets of spines point backwards. These allow them to hold fish or other prey in their mouths, and can help them swallow as well. 5. They Eat a Wide Variety of Protein-Rich Food Penguins eat a variety of fish and crustaceans. Specific food choices depend on where they live and the type of penguin they are. Larger penguins can dive deeper into the water, where they can catch squid and cuttlefish, while smaller penguins scrape krill from the underside of ice. Little penguins will only dive between 2 feet and 50 feet on average, but king penguins can dive to depths between 300 feet and 900 feet. Penguins are opportunistic, which means they will eat what they can find, within their preferences. Various penguin species, including yellow-eyed penguins and king penguins will eat everything from squid and crustaceans to fish like silverfish, sardines, sprats, opal fish, pilchards, and other smaller fish. The birds swallow the fish whole, which makes it easier to regurgitate the food for their chicks. If they are just feeding themselves, their gizzard breaks the fish down (instead of chewing with teeth like primates and ruminants do). 6. Penguins Are Monogamous (But Only for the Season) Coral Brunner / Getty During the breeding season, once penguins have chosen their mate, they stick with them, but they may or may not choose that same partner again next year. Some penguins lay two eggs per season, but the biggest species, like emperor or king penguins, lay just one. The partnered couple shares the work of incubation, turning the eggs and keeping them warm. Emperor penguins are the one species in which the male penguin takes full responsibility for egg incubation. Only little penguins lay more than one brood of eggs per season. 7. Penguins Can Drink Salt Water These birds are able to drink sea water thanks to their supraorbital gland, which is a special gland that filters salt out from their blood. Their system then pushes the salt out of their body via the penguin's nasal passages. 8. There Were Once Giant Penguins Mint Images - David Schultz / Getty The largest living penguin is the emperor penguin, which can reach a height of about 4 feet. However, fossil evidence discovered in 2017 in New Zealand revealed that human-sized penguins once roamed the land. They lived between 55 and 60 million years ago, likely weighed around 220 pounds, and stood about 5 feet, 10 inches tall. "That a penguin rivaling the largest previously known species existed in the Paleocene suggests that gigantism in penguins arose shortly after these birds became flightless divers," wrote the researchers. These were not the only large penguins in prehistory, but they are the oldest and biggest scientists have found so far. 9. Yes, All Penguins Are Black and White No matter where you find them, or how large or small they are, all penguins are what scientists call "countershaded." They have black backs and the topsides of their wings are black, while their necks, breasts, and bellies are white. Their coloration pattern serves as very useful camouflage. Penguin predators like orcas and seals mostly swim below them in the water, and when they look up, it's harder to differentiate between penguins and the water surface. From above, their dark backs are less detectable as they blend in with the water around them. However, since most penguins live in polar regions that are often snow- or ice-covered, they are highly visible on land. 10. Color in Penguins Is Generated by Structures Not Seen in Any Other Animal Penguins may be mostly black and white, but flashes of color such as blue or yellow are important as signals to other penguins. And according to fossil records, now-extinct penguins were even more colorful. Interestingly, they've developed unique microstructures for that color that aren't seen in any other animal. This is because they developed them separately over time from the types of coloration seen in other birds. However, unlike other birds, which often need to eat certain foods to generate color in their feathers, penguins are able to produce pigments in their feathers themselves. 11. It's Unclear Where Their Name Comes From A group of penguins in the water is called a raft, and on land that group is called a waddle, but the origin of the name for the species of bird in general is a bit of a mystery. It first appears in the 1500s as another name for the great auk — Europeans who first encountered penguins thought they looked like the Northern hemisphere bird (though they are not related). So dictionaries like the Oxford English Dictionary and American Heritage Dictionary suggest the word penguin comes from the Welsh word for "head" (pen) combined with the word for "white" (gywn). Another theory of the origin of the word is that it comes from the Latin word pinguis, meaning "fat or oil." 12. Penguin Populations Are Declining According to the IUCN, the populations of most penguin species are declining, and five species have been declared endangered: the African penguin (Spheniscus demersus), the Galápagos penguin (Spheniscus mendiculus), the yellow–eyed penguin (Megadyptes antipodes), the northern rockhopper penguin (Eudyptes moseleyi), and the erect-crested penguin (Eudyptes sclateri). Most of the ways humans can help penguins involve keeping the animal's home and hunting grounds — the ocean — clean and healthy. Ensuring penguins have enough to eat and minimizing climate change so that penguins who depend on ice can still live in those areas are important, too. Save the Penguins You can help save the penguins by making a few changes at home: Only buy and eat fish from responsibly managed fisheries, since overfishing limits the available food for penguins. Support the creation of marine reserves, where all animal and plant life are protected from fishing. Support legislation that fights climate change or supports carbon reduction goals. Do your best to use less power, drive less, and otherwise use less energy to reduce your contribution to climate change. View Article Sources Jouventin, P., et al. "Genetic Isolation and Divergence in Sexual Traits: Evidence for the Northern Rockhopper Penguin Eudyptes moseleyi Being a Sibling Species." Molecular Ecology, vol. 15, no. 11, 2006, pp. 3413-3423., doi:10.1111/j.1365-294X.2006.03028.x Alizadeh-Birjandi, Elaheh, et al. "Delay of Ice Formation on Penguin Feathers." The European Physical Journal Special Topics, vol. 229, 2020, pp. 1881-1896., doi:10.1140/epjst/e2020-900273-x Enstipp, Manfred, et al. "The Dive Performance of Immature King Penguins Following Their Annual Molt Suggests Physiological Constraints." Journal of Experimental Biology, vol. 222, no. 20, 2019., doi:10.1242/jeb.208900 Ropert-Coudert, Yan, et al. "An Exceptionally Deep Dive by a Little Penguin Eudyptula minor." Marine Ornithology, vol. 34, 2006, pp. 71-74. Sato, Katsufumi, et al. "Buoyancy and Maximal Diving Depth in Penguins: Do They Control Inhaling Air Volume?" Journal of Experimental Biology, vol. 205, no. 9, 2002, pp. 1189-1197., doi:10.1242/jeb.205.9.1189 Chilvers, B.L., et al. "Diving Behaviour of Yellow-Eyed Penguins, Port Pegasus/Pikihatiti, Stewart Island/Rakiura, New Zealand." New Zealand Journal of Zoology, vol. 41, no. 3, 2014, pp. 161-170., doi:10.1080/03014223.2014.908931 "Sphenisciformes: Penguins." Animal Diversity Web. Agnew, Philippa, et al. "Variation in Reproductive Performance of Little Penguins (Eudyptula minor) Attributable to Double Brooding." Journal of Ornithology, vol. 155, 2014, pp. 101-109., doi:10.1007/s10336-013-0992-x "Aptenodytes forsteri: Emperor Penguin." Animal Diversity Web. Mayr, Gerald, et al. "A Paleocene Penguin from New Zealand Substantiates Multiple Origins of Gigantism in Fossil Sphenisciformes." Nature Communications, vol. 8, no. 1927, 2017., doi:10.1038/s41467-017-01959-6 Clarke, Julia, et al. "Fossil Evidence for Evolution of the Shape and Color of Penguin Feathers." Science, vol. 330, no. 6006, 2010, pp. 954-957., doi:10.1126/science.1193604 Thomas, Daniel, et al. "Vibrational Spectroscopic Analyses of Unique Yellow Pigments (spheniscins) in Penguins." Journal of the Royal Society Interface, vol. 10, no. 83, 2013., doi:10.1098/rsif.2012.1065 "Penguin." International Union for Conservation of Nature Red List of Threatened Species.