Bird Brains: Testing Bird Intelligence
|
|
Compared to reptiles, birds and mammals have much bigger and more developed forebrains and midbrains. Aside from that, bird brains are very different from mammal brains. For a long time, scientists thought that the differences in brains proved that birds were less capable of learning than mammals, and that birds were overall stupider than mammals of similar size. Now we know better! Birds are actually very smart compared to mammals, though some species are definitely smarter than others. Ornithologist John K. Terres wrote that birds in the crow family have probably achieved "the highest degree of intelligence" found in any birds. Other scientists believe that birds in the parrot family are at least as intelligent. In this lesson we'll look at some of the ways that scientists have studied animal intelligence and try some experiments to learn about how smart our own pets are.
To test how well animals reason, scientists can do several experiments. In one test called the Krushinsky problem, an animal looks into a chamber with two dishes. One has food, the other is empty. Then the scientist moves the dishes behind two trap doors so the animal can't see either dish, and watches where the animal goes.
|
|
Dogs and crows solve the Krushinsky test very quickly. Cats, rabbits, pigeons, and chickens do poorly on this test.
If your class has a pet, design a test similar to the Krushinsky problem to see how readily your animal solves it. Students who have pet dogs might try the experiment at home. If students try this on different breeds of dogs, how did the breeds compare?
To test how well animals can count, scientists can train animals to learn to distinguish between two and three sound tones. Monkeys have to go through 21,000 trials to figure this out, and rats never learn how, but birds have little trouble with this. Another test shows birds a picture of a number of objects, and places different numbers of objects in front of several boxes. The box with the same number of objects in front of it as the picture has food and the others are empty. This test proved that ravens and parakeets can learn to count as high as 7.
One of the ways scientists can test avian intelligence is by analyzing their forms of communication. It's very important for scientists to understand the contexts of bird sounds--what is happening when a bird makes each kind of call, and what other birds do when they hear each different call. When we hear a sound and look up and see what's happening, we're making an observation and can make guesses about what the sound means, but it takes thousands of these observations to be certain about their meanings. One measure of bird intelligence is in the size of its "vocabulary." To hear vocalizations and learn their meanings for a few species, see Journey North's Animal Dictionary.
For centuries or more, people have yearned to speak to animals. Dr. Doolittle is a popular character in books and movies because so many people wish we could speak to animals, too. Dr. Irene Pepperberg started doing research on an African gray parrot named Alex in 1977, teaching him the names of things and ways of describing objects using shape, color, number, and other catagories. Now Alex can name many objects, answer questions about them, and carry on interesting and complex conversations with Dr. Pepperberg and some other humans. No one has ever done such an extensive long-term study of an individual bird, so it's not certain whether other birds can have such a varied and complicated vocabulary or the ability to reason and answer questions.
- Imagine you are a scientist trying to develop an animal intelligence test for your favorite species. How do these animals' body shapes, sizes, and special needs affect what kind of test they can take?
- Can you think of some problems scientists face when trying to compare the intelligence of a dolphin and a crow? A cat and a gerbil? A dog and a bat?
- Do you think scientists will ever be able to communicate clearly with animals other than parrots? What species might be easiest to communicate with, and why? What species might be very difficult to communicate with, and why?
© 1997 – 2019 Journey North. All rights reserved.
