Penguins are instantly recognizable for birders and non-birders alike, but why? What makes these birds so special and unique that they can captivate nature-lovers of all ages?
Types of Penguins
Depending on how closely related species are classified, there are 17-18 species of penguins in the world, all in the scientific family Spheniscidae. The general term “penguin” is believed to have originated from the Latin term pinguis, which means fat. Indeed, these birds with their pudgy bodies and streamlined shape can look fat, but they are highly specialized for their unique environments. Despite a wide range of sizes and appearances, penguins share many unique characteristics, and understanding those characteristics can help birders better appreciate how amazing penguins can be.
All penguin species are found exclusively in the Southern Hemisphere, though the Galapagos penguin does occasionally feed just barely north of the Equator in tropical waters. Other penguin species can be regularly found in South America, Africa, Australia, New Zealand and of course, Antarctica. As pelagic birds, all penguins spend much of their lives at sea, but when on shore they often favor rocky shores, beaches and ice fields where the shape of the ice might provide some protection from harsh winds. Their overall wide ranges at sea vary depending on ambient currents, oceanic water temperatures and food supplies, though they often return to the same breeding grounds each year.
Penguins are some of the most highly adapted, specialized birds in the world. Everything about their bodies is designed to help them survive in their marine environment, including the frigid waters near Antarctica.
- Body Shape: Penguins have stout, compact bodies with short necks and rounded heads and shoulders so they can be more streamlined swimmers. This body shape is also more efficient for heat retention so the birds can stay warm in inhospitable climates.
- Posture: These birds have an upright posture with their legs and feet set far back on their bodies. This is part of their streamlined shape, but it makes walking more difficult and awkward, and instead, penguins often waddle.
- Flippers: Penguins' wings are highly specialized flippers with fused elbows and wrists for greater strength in swimming. The wing shape is very thin and tapered to further aid swimming.
- Plumage Color: All penguins have black-and-white coloration called countershading. This type of camouflage protects the birds from predators while on land an in the water, and it helps them stay disguised from their prey as well. The exact markings vary from species to species.
- Plumage Structure: From a distance it may seem that penguins have no feathers, but in fact they have nearly three times as many feathers as flying birds. A penguin's feathers are very short and compact, and are very densely arranged on its body to provide better insulation in the water.
- Legs and Feet: Penguins have short, thick legs and powerful webbed feet that aid in swimming to a minor degree, though they use their flippers for their primary underwater propulsion.
- Bill: A penguin's bill is specialized for its piscivorous diet, and the thick, strong bill is hooked on the upper mandible to allow easier feeding on fish, krill and other aquatic animals. The exact shape of each species' bill depends on its specific diet.
- Supraorbital Gland: All penguins, and many other pelagic birds, have a specialized supraorbital gland that helps extract excess salt from their blood and excrete it through a special cavity in the bill. This helps keep the bird's body chemistry balanced even when it spends much of its life in the sea.
Penguins use their specialized bodies for specialized behavior that helps them survive.
- Swimming: Penguins are superb swimmers with the ability to dive well below the water's surface in search of prey, including fish, krill, squid and other creatures. They use their flippers to propel themselves through the water, and they can stay below the surface for long periods without any detrimental results.
- Fasting: Depending on the species, penguins may fast up to 100 days or more at a time during the breeding or moulting seasons when they are unable to enter the water to hunt. During these types of fasts, they can lose a significant proportion of their body weight.
- Porpoising: While swimming, penguins will leap out of the water in shallow arcs, a maneuver known as porpoising. This can help them surprise prey or evade predators, and it also helps them breathe and insulates their plumage with a layer of tiny bubbles.
- Tobogganing: Penguins are ungainly walkers, and on land they often use tobogganing – sliding on their bellies and using their flippers and feet to move and change direction. This is a faster, more efficient way for penguins to travel over snow and ice.
- Huddling: To protect themselves from harsh winters, particularly in Antarctica, penguins will huddle as a group to share body heat. This helps protect the flock against wind and cold, and individual birds will change position periodically so every bird has a better chance of survival.
Penguins are unique birds with many physical and behavioral adaptations that help them survive in the southern oceans. These adaptations give the birds a distinct appearance and actions that both birders and non-birders can easily recognize, and makes penguins some of the most familiar birds in the world.
Photo – Emperor Penguins © Eli Duke