By: Joey Wu
There are many types of birds that surround our world: majestic eagles, soaring high in our skies; the friendly chickadees and other songbirds, bringing a lively tune to the neighborhood; elegant herons, gracefully waltzing through the ponds.
While the thought of a bird evokes a multitude of responses, the common ground revolves around the concept of flight. And through a cursory thought, flight seems to be a pretty abundant generalization for birds - most of our daily experiences revolve around the avians in the sky.
However, penguins can’t fly. Interestingly enough, they aren’t the only birds that are flightless! In fact, a few others include steamer ducks, wekas, ostriches, kiwis, kakapos, and cassowaries!
What, you may ask, makes these birds so special? Why would they have wings if they cannot fly? If not for flight, what do they use their wings for?
Over a process known as evolution, where populations of animals adapt to changes in their environment to better their chances of survival, you can easily determine why penguins fly - simply, they have no need to!
Penguins spend most of their time in the water, shooting out of it only to take breaths of air (a process known as porpoising). Since they are swimming, their bones are dense and thick unlike their aerial counterparts (birds of flight have air pockets inside their bones to help resist the weight of gravity). Additionally, the weight of their bones helps them resist buoyancy (the upward force that helps you float) and prevents them from sinking into the water.
Since penguins have a diet that consists almost completely of aquatic organisms (namely, fish), their evolutionary process pushed them towards flightlessness in order to assist their swimming. With this in mind, it seems natural that penguins can’t fly in the air - after all, they were built to fly through the water!
The undulation of their wings is also built in a way that supports streamlined swimming; besides their shape and range of motion, penguins secrete oils to help make their fins waterproof. This makes the wing hydrophobic, meaning “water-fearing,” since oil and water don’t mix. Since they are built for swimming, their wings are not functional for flying.
Ostriches are another flightless bird. Being a large bird that grows over 9 ft tall and 800 pounds, these birds are truly one of a kind! On one hand, they are much too heavy to fly (imagine the energy their poor wings would need!) On the other hand, their long legs are meant for running instead of flying.
Many birds like ostriches don’t have pectoral keels, so their wings are too underdeveloped to lift their massive bodies. While they have wings, they use them for a completely different purpose, just like penguins.
Ostriches evolved in a place where they faced little predatorial pressures, so they were able to grow in size over the years, amassing into the large birds that they are today. Since they faced little competition in their environment, they also lost the necessity to evade predators through flight. After growing to their maximum size to thrive in their environment, they became so large that flight wasn’t necessary!
Ostriches use their wings for balance and steering while they run; as they race at large speeds, they turn their wings slightly to bend and twist in directions rapidly. While their wings aren’t meant for flight, they still have an important role in their life.
As you can see, though a few birds such as ostriches and penguins cannot fly, their wings are still essential for their survival and everyday function. Just because these birds can’t fly doesn’t mean that their wings don’t work for anything!
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