Study shows birds have remarkable brains

The next time someone calls you a bird brain, you can thank him. Even though that comment is usually intended to be less than kind, the brain of a bird is quite remarkable.

Consider birds in migration. They depart their northern nesting territories to fly sometimes thousands of miles to wintering grounds. They can find their way at night, in poor weather and over land that may have changed since their last flight.

Ornithologists now believe that many migratory species actually have a complicated set of magnetic sensors in their brains, allowing the birds to use the earth’s magnetic field to find its way. These sensitive indicators register the exact location of the preferred destination and allow a bird to use magnetic variations to find its way. The use of this internal mapping is a combination of learned and genetic behavior. A young bird in its first migration will still be able to generally find its way. Adult Tundra Swans nesting in the arctic depart south before their cygnets are ready to fly. Once fully flighted, the young birds find their way to wintering areas without the benefit of experience. However, studies have shown that adult birds are better able to compensate for inclement weather and still arrive at their destination. Along with this internal compass, birds can use the position of the sun to keep their bearings, and internal GPS.

Many species spend long periods of time in the air during these migratory flights, sometimes days. Their brains are designed to sleep one hemisphere at a time, a feature called unihemispheric sleep. During long flights, one eye will close to rest half the brain, while with the other open they can navigate and avoid dangers. This behavior may be associated with micro-naps, sometimes lasting only a few seconds. These tiny periods of sleep give the bird’s brain needed rest even while in flight. We lowly mammals would be hard-pressed to function very long without a decent rest.

A superb memory can be a positive adaptation when it comes to food collection. Jays and crows are masters of stashing food and finding it again, sometimes months later. They will take acorns and other seasonal treats and store them in tree bark, under leaf litter or any other safe storage spot. When the natural food source disappears, they have a pantry waiting. Clarke’s Nutcrackers have been observed hiding as many as 30,000 pine seeds over an area of 200 square miles, and later finding over 90 percent of them.

For thousands of years, many have considered the use of tools to be a feature only found in humans. However, many birds have now been found to use humans to actually assist them in food gathering. In Japan, Carrion crows have been observed placing nuts in the road so passing cars will drive over them and crush open the hard shells, then the crow returns to collect his prize. Gulls collect shellfish, then drop it from on high to break open on hard pavement.

In the Galapagos, the Woodpecker Finch will pluck a twig, shape it to its liking and use the tool to dig in holes after insects. This behavior is apparently taught from generation to generation. In captivity, other related species have learned to fashion tools, even though in the wild their relatives do not. There are cases of tool use with birds that have been documented to have come about during the course of observation; the birds did not use tools, then shortages or other variations in food supply caused them to become tool users to survive.

One of the best-known cases of bird intelligence is that of Alex, the African Gray Parrot. He has been taught a vocabulary of more than 100 words and can correctly use conceptual words such as those for colors and shapes. His language abilities are considered equal to a 4-year-old child. Many species of birds in the parrot and corvid families have been taught to speak. Until controlled studies showed otherwise, this was considered just mimicry. But now scientists believe that these birds actually use language the way we do, to communicate ideas.

If all this doesn’t convince you that birds have amazing brains, then watch them in play. I have watched Ravens tumble down an icy slope, stop at the bottom, shake off and fly back to the top to do it all again. There is no survival trait learned here, no food gathered or mating conducted. These birds were simply enjoying themselves. What bird brains!

Nancy Wade is member of the Mat-Su Birders and Alaska WildBird Rehabilitation Center. Send birding questions for her column on birding to alaskaflamingo@yahoo.com.