Page 34 - 2007 DT 12 Issues

Aspects of Intelligence, Part 2. of episodic memory—the ability to when one observer was present, and
mentally travel forward and backward in a different set of trays under the
n the last 15 years, rigorous experi- in time—and even imagination. watch of a different observer. Upon
ments and observations of animals Scrub jays hide several thousand returning to their trays and finding one
Iin the wild and in the laboratory pieces of food each year and remem- of the observers present, they focused
have produced some startling results ber where each piece is stashed. To on moving items from the set of trays
with a host of species, challenging test whether jays remember the ex- they had used when that particular
our long held assumptions about the perience of hiding the food as well observer was around.
origins of intelligence. Intent-specific as where it is hidden, Dr. Clayton Such behavior suggests that
communication and tool use can be gave the animals moth larvae and animals can remember and discrimi-
used to determine a level of animal peanuts to hide. The birds favor the nate among individuals that possess
intelligence. Other aspects, such as larvae when they are fresh. Later, the different knowledge. People do this
episodic memory, cognitive capacity birds that were allowed to return to by “theory of mind,” that is, imagin-
and imagination, are harder to define. their caches after waiting four hours ing plots running through someone
A wealth of recent data, however, else’s head. Although the
paints a fascinating picture. Some of scientists do not equate
the smartest subjects under study are the jays’ abilities with
lurking in our own back yards. theory of mind, some con-
Except for certain parrot species, tend that the jays seem to
corvids may be the smartest of all have the mental agility to
birds. Natural history author Can- imagine that a particular
dace Savage writes, “Crows, ravens, individual is likely to steal
magpies and jays . . . are able to make their goods sometime in
complex decisions and show every the future.
sign of enjoying a rich awareness.” Ravens and crows are
Jays, for example, will sit on an considered by many to
ant nest, allowing the angry ants to be more intelligent than
douse them with formic acid, a natural canids—coyotes, wolves
pesticide which helps rid the birds of tended to dig up those containing the and dogs. Ravens have the largest
parasites. Carrion crows use road traf- larvae. Birds that had to wait five days relative brain size of any birds. They
fic to crack tough nuts at traffic light to return dug up the peanut caches, will call wolves to prospective meals
crossings, patiently waiting for a red instead. To avoid the possibility that to expose a carcass which the birds
light to retrieve their meal. Controlled the birds were signaled by the odor will then scavenge. They’ll also wait
experiments have uncovered even of rotten larvae, Dr. Clayton had first for other birds with specialized forag-
more sophisticated examples. dumped all the filled caches and re- ing skills to make a catch, then, snatch
As reported in the April 3, 2007 filled them with mud. the subdued prey for themselves.
New York Times article, “Time in the When stashing food in the wild, a Crows have been compared to
Animal Mind,” Nicola Clayton, a pro- scrub jay keeps an eye out for any oth- great apes and chimpanzees in aspects
fessor of comparative cognition at the er jay that may be watching, returning of intelligence because of their large
University of Cambridge in England, later to defend its hoard. In one exper- brains and social skills. A captive New
has conducted a series of ingenious iment, the birds were given a set of ice Caledonian crow named Betty be-
laboratory experiments with Western trays filled with pellets in which they came famous when she was observed
Scrub Jays over a period of more than cached some of their favorite foods in making various hooks out of wire
10 years which strongly suggest that the presence of an observing jay. The to obtain out-of-reach food. In the
the resourceful jays possess a form birds cached food in one set of trays wild, Betty’s cousins routinely make

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