Book Review: Bird Sense: What It’s Like to Be a Bird, by Tim Birkhead

BirdsenseWhat is it like to be a bird? It’s a question that’s been asked for centuries, and it’s still somewhat of a mystery. The answer may very well seem to be, “You have to be a bird.” We can only really imagine what it’s like to stoop at incredible speeds like a Peregrine Falcon, dive down into dark, icy water like a penguin, or feel the urge to migrate south. But even if we can’t feel the way a bird does, we can still learn how their senses work, especially with new technology and knowledge. The new book, Bird Sense: What It’s Like to Be a Bird, by British ornithologist, Tim Birkhead, will help on this quest.
Everybody knows that humans possess five senses: sight, hearing, touch, taste, and smell. Birds also possess all these senses, along with magnetic sense, but like us, they seem to rely mostly on sight and hearing. Since they use their eyes and ears so much, as Mr. Birkhead points out, we tend to think that they don’t smell, touch, or taste, though they do. He goes onto say that we often comprehend things by our own standards and limitations, in order to understand. This makes truly understanding how they live difficult, but, with the aid of technology, we can comprehend easier.
Sight, the first sense explored in this book, is one of a bird’s best senses. If you compare bird eyes to mammal eye, you will find that birds do have larger eyes relative to the size of their skull. The reason for this is fairly obvious: they have to avoid hitting objects while in flight, are mostly active during daylight hours, and their prey is usually fast, or camouflaged, or both. Size is important, too: the larger the eye, the larger the retina, the better you can see. The author compares it to television screens; an image is much better on a 36-inch screen than on a 12-inch because there are more pixels available to make up the image.
Next the author addresses hearing, a bird’s second most important sense. Unlike humans, birds don’t have a pinna, or external ear; the function of the pinna is to help collect sound, but having one wouldn’t be aerodynamic in flight. Birds seem to have made up for this lack because they still have excellent hearing. Another difference is that birds replace their cochlea (a space filled with fluid that has a membrane where fine hairs grow) often, while humans don’t; once we damage these hairs, they are permanently damaged. Ever wonder if any nocturnal birds use echolocation like bats? A few species actually do! Scientists were able to prove this by stopping up the birds’ ears. The birds would send out clicking sounds, but since they weren’t able to hear the clicks bounce back, they would fly into walls.
As far as touch is concerned, birds’ beaks are much like our fingers: very sensitive to touch because they have many nerve endings. This is especially true for dabbling ducks, parrots, and other birds that rely on their bills to find food. If you open a duck’s beak, you will notice that tiny pores surround the edge and if you could look at them under a magnifying glass, you could see a papilla (a group of about twenty to thirty microscopic nerve endings) extends from each pore. These are the reason that ducks are so effective at straining out food items from pond muck and mud.
Who says birds can’t taste? Birds do have comparatively few taste buds, around 400 to 500 with Japanese Quail have the fewest of species studied—only 60!—when judged against humans who have 10,000. Despite this, they can still distinguish the same tastes that we can: salt, sour, bitter, and sweet. Hummingbirds can taste the amount of sugar in nectar and fruit-eating birds certainly distinguish between ripe and unripe fruit. But probably the best-known example is of Blue Jays refusing to eat Monarch butterflies because they taste bitter.
And what about smell? According to Mr. Birkhead, many ornithologists do not like hearing that birds can smell. “Ask any of them and they’ll turn up their noses and say no, there’s not much going on in the olfactory department of a bird’s brain,” he notes. The Father of American Ornithology, Mr. John James Audubon himself, was the one to start this myth. Experiments in subsequent years were conducted, but they seemed to prove that birds couldn’t smell. Even when scientists did other tests that proved the contrary, these results were ignored. It wasn’t until 1950 Betsy Bang, a medical illustrator at Johns Hopkins University, proved that birds most certainly did have a sense of smell. As she dissected and drew birds’ respiratory systems, she couldn’t understand how animals with good-sized nasal cavities couldn’t smell. She performed experiments to help prove this fact. Since then, there have been other studies that prove this fact. In spite of this evidence, some scientists still have a difficult time accepting the idea that birds do have a sense of smell.
How do birds find their way to and fro from their winter grounds to their breeding grounds? For centuries, people have wondered this. Releasing seabirds like shearwaters many miles from their nests and documenting their return straight home seemed to prove they had some kind of navigating instinct. After many, many years of research, it was discovered birds did indeed have an internal magnetic compass. Not only that, birds have a “magnetic map” which works somewhat like a GPS system, the author says. Instead of satellites, though, birds rely on the earth’s magnetic field. Even birds that don’t migrate, like chickens, have this magnetic sense.
The author also discusses avian emotions. Afraid that they would be attaching human qualities and sentiments to birds, most scientists, and many birders, don’t like to think of birds as having emotions. As Mr. Birkhead writes, there is a “difficulty of trying to imagine how the mere firing of neurons can create a sense of awareness or feelings of discomfort or euphoria.” Just as we don’t always understand how a person is feeling, we can’t understand what feelings a bird possesses.
One of the features I liked best about this book was the fact the author does not just tell you what we now know about bird senses; he describes how we came to that knowledge, over the years, a few times going all the way back to the ancient Greeks. Despite the fact it deals with some fairly technical information, it is easy to read and understand. I enjoy learning about all aspects of birds and birding, but I must admit: I’m drawn to scientific research. I think birders who, like me, enjoy reading about scientific studies and discoveries, will find this book a must-read. Perhaps we don’t possess magnetic sense like birds do, but we are attracted to them like metal to magnet.

AlexandriaAbout the author: Alexandria Simpson is an avid, sixteen-year-old birder from Santa Anna, Texas. While she wishes she could say she has been birding all of her life, instead she has spent the last four years making up for lost time. She wants to become an ornithologist and someday read scientific papers without falling asleep. Her photography, illustrations, and writings have won awards at local, state, and national levels.