A Parrots Foot Preference May Help Determine Its Talking Ability

As French neurologist, Paul Pierre Broca discovered in 1864, the function of speech is handled by the left side of the brain. But, unlike righties, some left-handers use parts of the right side of their brain for processing language. Dr. Peter Snyder, a neuroscientist at Allegheny General Hospital in Pittsburgh, was intrigued by whether this is strictly a human phenomenon or whether animal brains function the same way. So, he began to look for the right animal model. At the National Aviary in Pittsburgh, Dr. Snyder found the perfect candidates: parrots. Right-footed African Grey parrots, he determined, know more words than left-footed birds.
For 300 years, people have noted the parrots dexterity and tendency to favor one foot over the other when handling food. But all of the scientific attempts to quantify this behavior were deeply flawed, Snyder said. He began by developing the largest and most accurate study to date of parrot footedness, using more than 500 birds, enlisting the publics help. He created questionnaires describing a set of experiments and strict guidelines for carrying them out, and published them in bird magazines and on the Internet. From the responses, Dr. Snyder concluded that parrots in general show a tendency toward left footedness. Among one species, the Australasian Cockatoo, 82% of the birds are left-footed--close to the percentage of humans who are right-handed. That degree of preference is unknown in any other vertebrate animal, including primates.
Hoping to find a link between brain function and footedness, Dr. Snyder focused on the best avian talkers--African Greys. Parrot owners reported on the size of their birds vocabulary, providing lists of up to 300 words. Amazingly, the right-footed bird
s had memorized a significantly larger number of words than their left-footed counterparts. Even after adjusting for age and for how pushy the owners were about teaching them to talk, right-footers won wings down, Dr. Snyder said.
The evident link between foot preference and language skills in parrots is especially striking because its believed that birds split off from our branch of the evolutionary tree some 150 million years ago. Perhaps birds and people have followed a strangely parallel evolutionary path, Dr. Snyder notes, or else they share brain asymmetries inherited from an even older ancestor. Either way, he believes that the new findings will improve scientists understanding of why our brains are organized the way they are, and of how brains adopt a preferred handedness during fetal development. Such information could lead to new insights into the nature of brain disorders, such as those associated with strokes and epilepsy.
Dr. Snyder has treated patients with brain disorders affecting memory, comprehension, speech and other functions for more than 10 years. He has been a bird owner since 1986 and volunteers his time doing research at the National Aviary located inPittsburgh, Pennsylvania. He is the author of the”Pet Parrot Book,” a guide to help parrot owners better understand their pet, published by Barron's Educational Services, Inc.

Copyright 2000 Beth Shery Sisk

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