In 2001, anthropologist Jeremy Narby traveled deep into the Peruvian Amazon. There he discovered that colorful macaws consumed large quantities of clay on a daily basis, quantities that could easily be considered dangerous. Yet these birds thrived.
Further inspection revealed that macaws were fond of seeds that contained toxic alkaloids. The clay was consumed for a specific purpose: it bound these toxins so they could be speedily eliminated from the body. The clay was also rich in kaolin, a substance used by man to treat food poisoning.
How did the macaws become so smart?
In his book, Intelligence in Nature ( New York: Jeremy P. Tarcher/Penguin, 2006), Narby reveals why the word "birdbrain" is no longer tenable as metaphor for stupidity. Birds might have small brains, but they are uncommonly intelligent.
According to avian experts, anatomy textbooks on bird neurobiology need to be rewritten because they were based on an old paradigm - linear evolution.
Birdbrain and Evolution
How did "birdbrain" get such associated with such an uncomplimentary connotation? This misnomer came from the belief that evolution worked in a linear fashion, moving from fish to amphibians, to reptiles, then to birds and finally to mammals.
German neurobiologist, Ludwig Edinger, known also as the Father of Comparative Anatomy, assumed that evolution moved in a straight upward line: fish were least intelligent; humans were the most intelligent because they have the most highly developed neocortex. Avian brains, composed of clusters without the six-layer cortex, were assumed to be dominated by unintelligent, instinctual responses.
New studies are now challenging this classic view of neural evolution. One view suggests that avian brain clusters function in a manner similar to the six layer cortex in mammals. What this means is that while bird brains are anatomically different from mammalian brains, their functions are essentially the same. One brain is not better than the other; they both arrive by different means to the same functionality in behavior and intelligence.
Tool-Making Crows
Nature is filled with examples of smart birds. Researchers at Oxford University have discovered that New Caledonian crows can bend wire to create hooks which they use as tools to obtain food. They can even make spears out of barbed leaves to probe the underbrush for prey.
One crow named Betty showed remarkable problem-solving intelligence. Faced with a situation she had never encountered before, Betty modified objects into tools specific to the situation. This ability to evaluate a specific problem and modify a response to it is considered a sign of higher thinking skills.
Pigeon Memory
According to Avian Web, pigeons can memorize up to 725 different visual patterns. They can recognize all 26 letters of the English alphabets. Scientific tests have shown that pigeons can not only distinguish between photographs but also between two different human beings in a photograph.
Pigeons have been taught to distinguish between the color and stylistic features of paintings by Van Gogh and Chagall. They were trained by being rewarded for pecking at paintings by Van Gogh and discouraged from pecking at Chagall. After the training, the birds were exposed to works by both artists, works they had not seen before. Researchers wanted to see if the birds could tell the difference between the stylistic features of the two artists.
How did the birds do? Quite well. According to Narby, "the pigeons as a whole performed as well as a parallel group of university students majoring in psychology."
Pigeons have such a strong memory they have been trained since the days of Genghis Khan to be mail carriers. Reuters started its News Agency business in 1850 by using 45 trained homing pigeons to deliver financial news across the continent.
Songbirds and New Neurons
Not only do young birds learn from their parents, they develop new songs for new situations. Canaries, for example, often change their repertoires. Recent studies show that adult canaries generate new neurons each year, a discovery that overthrows the long-held view that adult brains never change. The discovery also suggests that intelligence in birds is sharpened by experience.
While the macaws are partial to a particular delicacy in the Peruvian Amazon, they are also smart birds - intelligent enough to counter its toxicity with clay. Like the human brain, bird brains are shaped by the environment. If intelligence is the ability to respond and adapt to new situations, then birds are very smart indeed.
Source:
- Blakeslee Sandra. "Minds of Their Own:Birds Gain Respect." Science Section.The New York Times. February 1, 2005.
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