By Mike King
Nature constantly presents organisms with new challenges along their way to surviving to reproductive age and leaving behind offspring. Animals meet these challenges by adapting incredible traits that allow them to thrive in their environment. When reminded of these adaptations, one might think of Bat-eared Foxes that use their massive ears to hear prey underground for great distances, New Caledonian Crows that sharpen sticks into hunting hooks, or Orchid Mantises that perfectly imitate flowers to ambush pollinating insects. Less commonly do we consider adaptations under the surface layer of animals. Are there mechanisms within an organism’s body as astonishing as those we can observe with the naked eye? As it turns out, penguins have a few tricks up their sleeves that may surprise you.
Penguins are extremely active animals. From lengthy Emperor penguin migrations to complex diving patterns exhibited by krill-hunting Gentoos, movement is of critical importance to every penguin species in the world. Many species spend all day out on the water swimming and hunting for food. With all of this waddling around, how do they find their way back to the colony? As it turns out, all birds possess some extraordinary adaptations for navigation; although penguins have the added disadvantage of being flightless. This makes it impossible for them to soar above the horizon in search of familiar landmarks leading them home. Scientists are beginning to understand some of the ways penguins can locate their colonies after long days spent far away.
Penguin researcher Anna P. Nesterova and her team recently spent time studying King penguin navigation in Antarctica. They observed that King penguins live in massive colonies that seem to be quite difficult to navigate. How then, do penguin parents find their way back to their chicks after a day out searching for food? It is known that penguins can recognize individuals through vocalizations, but this is only an effective strategy for King penguins within eight meters of their chicks.
Some penguins in the study were documented taking very lengthy, indirect paths to their chicks when returning to the colony after feeding to avoid aggressive encounters with resting neighbors. So, do King penguins simply wander, or is there something more to their navigation? The answer may have something to do with nighttime movement. As it turns out, many penguins were observed to leave and return to the colony in the middle of the darkness of night. Although King penguins can see 1.5 times better than humans, they are still incapable of seeing landmarks well at low-light levels. The researchers involved in this study believe that over time, penguins can learn the acoustic landscape of their colony, thus navigating by the unique sounds of their neighbor’s voices. It is also possible that King penguins use a method that science had only speculated about until this year—magnetism.
Overexpression in Yeast, Photocycle, and in Vitro Structural Change of an Avian Putative Magnetoreceptor Cryptochrome4, pubs.acs.org/doi/abs/10.1021/bi501441u?journalCode=bichaw
For years, researchers have known that birds navigate by sensing the magnetic field of the earth; but until just recently we did not know how this was accomplished. It was observed that birds have high levels of iron within their bills, which could possibly be used as a sort of compass. This was the prevailing viewpoint in the scientific community for years, but it lacked credible evidence. It seemed for a long time that the mystery of bird navigation would remain unknown to man—until now. Just this year researchers analyzed a special protein found within the eyes of birds, and it turns out it is critically important for navigation. This protein, called Cry4, is a type of photoreceptor that detects blue light. Birds are able to use these photoreceptors to actually see the magnetic field of the Earth. This amazing discovery helps us to understand how migratory birds can fly with perfect orientation through the complete cover of darkness. This protein has not yet been analyzed within the eyes of penguins, but Cry4 may be an essential tool for these seabirds to find their way to their chicks.
We do not yet know whether King penguins use acoustic landscapes, magnetic fields, or their memory to navigate through crowded colonies. However, each of these adaptations can and should be appreciated for the ingenious ways they help an organism rise above the challenges presented by its environment. People often use the term “life will find a way” to describe situations in nature that seem too extreme to support living organisms, yet still do. Through the observation of evolutionary adaptations such as navigation, we are better able to understand the extraordinary nature of life to overcome seemingly impossible odds. This characteristic defines the very concept of life—to continue changing, adapting, and evolving alongside the surrounding world; constantly pursuing a level of ecological balance that allows an organism to flourish despite overwhelming challenges presented to them.
What do you think about how penguins get around? Did you learn something new? Would love to hear what you think, what you learned, and more!
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