Birds may have a reputation for being less than geniuses, but researchers are
discovering that some are remarkably smart. Ravens, for instance, have the ability
to solve difficult puzzles, such as untangling a knotted string to free up a
tasty treat or figuring out how to steal fish by hauling in an angler's untended
line. And, as shown in "Are Animals Intelligent?," the first part of NATURE's
INSIDE THE ANIMAL MIND, crows on the remote Pacific island of New Caledonia
have learned a skill that people once thought only primates could master: the
use of tools. The birds use long, specially chosen twigs to spear the plump
grubs that hide deep beneath the bark of rotting logs.
Raven antics and New Caledonia's clever crows have helped make people much
more willing to admit that many animals, including birds, are quite intelligent.
Dolphins can follow complex instructions, for instance, while orangutans learn
complex tasks, such as washing clothes by hand, after just a few tries. And
even pigeons and parrots have shown an extraordinary capacity to recognize,
count, or name different objects.
But no bird has done more to give a whole new meaning to the phrase "birdbrain"
than Alex the African Grey parrot. More than 20 years ago, researcher Dr. Irene
Pepperberg of the University of Arizona began systematically studying Alex and
several other African Greys, parrots that are remarkable mimics, to understand
avian intelligence. "Before I began my studies, I knew that parrots could reproduce
the sounds of human speech, but that the general belief was that such vocalizations
could not be meaningful," Pepperberg has written. Today, her work with Alex
has challenged that notion. For instance, Alex can name more than 40 objects
and understands the concepts of "same" and "different," "absence," "quantity,"
and "size." Alex, Pepperberg says "has mastered tasks once thought to be beyond
the capacity of all but humans or certain non-human primates."
Happiness, sadness, anger, fear, love, hate-emotions play a pivotal role in
our lives. But do they loom large in an animal's world as well? Part Two of
NATURE's INSIDE THE ANIMAL MIND, "Do Animals Have Emotions?," explores that
question in fascinating detail.
In large part, researchers have found that emotions are accompanied by biochemical
changes in the brain. Fear, for instance, is accompanied by the production of
one set of brain chemicals that can make us alert and ready to flee, while pleasure
triggers the release of other chemicals that soothe and calm. But some emotions
aren't so biologically clear-cut. Shame, for instance, is a so-called "social
emotion," the product of attaching an emotional meaning to a behavior, such
as hitting another person, or lying, that may be appropriate in one social setting
but out of bounds in another. While researchers don't agree on how big a role
such social emotions play in the animal world, there is widespread agreement
that many animals share another emotional characteristic with us: stress. Indeed,
like humans, many animals can be harried and "stressed out"-with sometimes serious
health consequences.
Among the most remarkable studies of stress in animals are those carried out
on African baboons by Stanford University research Robert Sapolsky and his colleagues.
For three months each year, Sapolsky travels to East Africa's Serengeti plain
to examine how factors like a baboon's social behavior, personality, and rank
within its troop influence the levels of stress hormones produced by the ape.
By measuring the hormones found in each individual's feces, Sapolsky's team
has been able to show that baboon troops are high-stress societies, with higher-ranked
individuals maintaining order by intimidating lower-ranked troopmates. Indeed,
Sapolsky says, "Baboons and us are surprisingly similar . . . they can devote
a large part of each day to making each other absolutely miserable with social
stress."
Sapolsky's team has also shown that such stress can have real health consequences.
Stressed-out mothers, for instance, have more problems producing healthy offspring.
And sustained production of stress hormones can also damage the hippocampus,
a region of the brain central to learning and memory. So even though baboons
may not commute, do their bosses' dry cleaning, or pay income taxes, they suffer
very similarly from the scourge of stress.
As you read this, you are probably aware of reading this. Indeed, you can also
imagine yourself reading this-a sort of picture within a picture in your mind's
eye.
But do animals share this kind of consciousness? That is the question asked
by Part Three of NATURE's INSIDE THE ANIMAL MIND, "Animal Consciousness." The
program ponders just what consciousness is-and which animals might share this
trait with people.
Bees, for instance, appear to meet one of the requirements for consciousness.
They can create "mental maps," images they hold in their minds that allow them
to navigate around their environments by picturing themselves there. Chimps
and elephants appear to exhibit another consciousness trademark: an awareness
of death. Both animals grieve when family members die: elephants even linger
over the bones of long-dead relatives, seeming to ponder the past and their
own future. But are these behaviors enough to give bees, chimps, and elephants
membership in the consciousness club?
Researchers are actively debating the answer to that question. "Consciousness
is one of the hardest things to define and study," says Pete Chernika, an Austrian
researcher who has studied consciousness in dolphins and other animals. "In
experiments, for instance, dolphins appear to pass one consciousness test by
recognizing themselves in mirrors. And dolphins also exhibit a keen awareness
of the status and identity of other dolphins in their highly social groups,
he says.They know who mom is, who the leaders of the pod are, and how they should
behave around different individuals," he says. "They appear to be able to envision
themselves in relation to all these other animals and then act accordingly."
Indeed, many researchers believe consciousness is more likely in highly social
animals such as chimps and dolphins, who must be able to see themselves in relation
to others in their groups in order to get along. "Complex social interaction
puts a high priority on awareness of self and others," says Chernika. But he
warns that the more people study other animals, the more we realize how hard
it is to define consciousness-and how hard it is to decide who has it, and who
doesn't.
We recommend these Web sites for those interested in the subjects shown on the
program. All links are valid as of January 3, 2000.