Revealed: The Surprising Reasons Why Penguins Can't Fly

Why penguins cannot fly
Penguins are flightless birds who dive deep into the sea. A study was conducted to understand why these birds can't fly. An account of this research, pertaining to their diving abilities and inability to swim, is given here.
Swimming Champs!
Penguins can swim underwater at a speeds between 15 and 25 mph. Emperor penguins can dive to a depth of more than 500 meters.
Penguins are aquatic birds found in the southern hemisphere. These birds easily attract our attention owing to their unique form and body features. Although penguins are placed under the category of birds, their appearance is more like aquatic creatures. Also, their wings are smaller in proportion to the size of their body. They are flightless birds with flipper-like wings.

A research was conducted by a team led by Kyle Elliott from the University of Manitoba, Winnipeg, to find out why penguins cannot fly. The conclusion derived from these research activities was that a penguin's flippers are better suited for swimming and diving. It is difficult to fly with the help of such flippers. In fact, the flippers of penguins were never meant for flying. Their sole function was to assist penguins to swim efficiently. In other words, penguins would have developed much better wings if they had chosen flying over swimming.
Comparison Study
A study was conducted on guillemots to obtain an insight on why penguins cannot fly. Researchers have agreed upon the fact that a bird's wings cannot perform both, swimming and flying. It is assumed that, at a certain point in the process of the evolution of wings, penguins had to choose between flying and swimming; they chose swimming.

The research conducted on cormorants and murres proved to be of great help in understanding why penguins can't fly. Both these birds have an anatomical structure similar to that of penguins. Recorders were fitted on murres to measure the depth, time, and temperature of dives. On the other hand, cormorants were fitted with data-loggers to record temperature, depth, and changes in acceleration that takes place while diving.
Thick-billed Murre (Uria lomvia)
This bird is also known as Br√ľnnich's Guillemot. The murre flaps its wings to wade through water at the time of diving. Tests conducted on murres revealed that they needed 30% greater energy than penguins of the same size.
Pelagic Cormorant (Phalacrocorax pelagicus)
The Pelagic Cormorant is found off the Pacific coast. The cormorant uses its webbed feet to propel itself through water. The energy costs of diving in these cormorants were higher than that of penguins as well as murres.
penguin dancing
The wings (flippers) of penguins are suited for swimming; it is evident from how their physical features have evolved over the course of time.
  • The wingspan of a penguin is smaller than that of most birds. One of the benefits of having such wings is that the drag experienced while swimming is reduced to a great extent.

  • One of the differences observed in the flight of a penguin and that of other aquatic birds is that a penguin employs a beating motion of its wings. Most aquatic birds move underwater by means of the paddling movement of their webbed feet.
  • The body of a penguin is bulkier than that of other aquatic birds. It helps it dive deeper and keep its body insulated from the surroundings.
Energy Burned in Flying
The comparison of the energy burned in flying to that at rest should help understand whether a bird is an efficient flyer or not. A murre spends 31 times as much energy while flying than at rest. The energy spent is quite high if compared to most flying birds. Thus, we can conclude that murres waste a lot of their energy in their flight. Penguins, on the other hand, have totally given up on flying, to conserve energy.
Penguins lost their ability to fly in the course of evolution, millions of years ago. So how (or rather why) did they lose this ability. The explanation presented by researchers is that penguins are efficient swimmers, and they gave up flying for the sake of swimming. Murres, on the other hand, can fly as well as swim; however, flying comes at the expense of a large amount of energy spent. Thus, we can say that murres are yet to make up their mind whether to fly or to swim.

So what is the significance of studying the thick-billed murre's flight. This comparative study helps us understand that in spite of higher flight costs, murres did not shed their flying instinct. This is because, even if flying is a laborious activity for the murres, they benefit from it in different ways. Flying allows them to flee predators. The action of flying also helps them move between their nests and foraging grounds. It might be one of the reasons why murres didn't give up flying, even if this activity consumes a lot of energy.

Finally, we can say that penguins were smart enough to shed their flying instinct to survive in the predominantly aquatic surroundings of the Southern Hemisphere. They have evolved into efficient diving creatures.