Ask A Scientist

Why can’t penguins fly?

Asked by: Amelia Kuhnen
School: St. James Middle School
Grade: 6
Teacher: Mrs. Cora Walter
Hobbies/Interests: Softball, basketball and dance.
Career Interest: Dermatologist

Answer from George Catalano

Professor of Mechanical Engineering, Director of t

Ph.D. School: University of Virginia, Aerospace Engineering, 1977

MD School: Harvard

Research area: Turbulence, Fluid Mechanics, Aerodynamics, Environmental Ethics, and Modeling Ecosystems.

Family: Wife, Karen, is a registered yoga teacher at Inner Space Yoga Studio; lives with 3 Alaskan Malamutes, two more in our hearts

Interests/hobbies: All things Italian, Creative Arts, Model trains & cars

Penguins, while sharing some of the same characteristics of other diving birds such as loons and various ducks, have evolved in ways to help them survive in their natural environment. Their bones are solid rather than hollow as typically found in birds that fly through air. This extra bone mass serves the same purpose as ballast in submarines—it allows penguins to submerge beneath the surface of the ocean. In addition, the once useful wing-like structures are now paddle-like flippers, similar to those we use to paddle a canoe, enabling more rapid and efficient motion through the water. As penguins do not need to escape predators on land, they have given up their ability to fly through the air for more maneuverability and speed as they travel through the ocean Penguins belong to a group called Sphenisciformes, in which all species are flightless and aquatic. Yet the characterization as flightless may not be quite accurate. In fact what does it mean to fly? And where do you fly? Can it only occur in our Earth’s atmosphere? We often hear of space flight as well as NASCAR racecars flying around the oval track. Let’s see if we can make some sense of all of this and answer the question whether or not those tuxedo-wearing birds can in fact take flight. According to, who offer a wide range of different definitions, to” fly” is most commonly interpreted as “to travel through the air; be airborne.” They go on to assert that, "Man cannot fly." Well, as we know now after the success of the Wright Brothers, humankind can indeed fly so maybe that limited definition of flight does not help us understand all the possibilities of flight in the natural world after all. I would suggest that something “flies” when it isn’t firmly planted upon solid ground. Yes, birds such as the majestic eagle, the boisterous crow and the beautiful cardinal all do fly but so too do the dolphin, the shark, the killer whale and our black and white feathered penguin. Eagles, crows and cardinals each propel themselves through the fluid we have named “air.” Dolphins, sharks, orcas and penguins propel themselves through a different fluid, one that we have named “water.” Though air and water seem incredibly different, they really are not and are in fact both key elements required for the existence of life on our beloved planet.  Air may be 1/1000th times as dense as water, but birds rely on the shapes of their bodies, tails and wings to provide the forces required for them to move from one tree to the next and to control their flight movements. So too do dolphins, sharks, orcas and penguins use their body shapes, tails and fins to move in a controlled way from one location in the ocean to another. So the next time someone tells you humankind cannot fly, ask that person to specify the fluid. Then head out to the nearest swimming pool, dive in and fly through the water with the greatest of ease, making sure to think back to our favorite, tuxedoed -friend, the penguin

Last Updated: 3/1/17