It
was once believed that the function of the brain was
to cool the blood. That theory went extinct before
the Dodo, but despite the now accepted knowledge
that the brain is involved in processes of thought,
we are still little further in unlocking many of its
mysteries. Professor Louis Lefebvre and his team of
researchers in the Department of Biology at McGill
University have been studying the evolution of
intelligence for the past 7 years. By focusing their
research on innovative bird behaviors, they have
managed to shed light on some of the mind-bending
questions that have perplexed scientists for
centuries.Since the
early 1800's scientists had suspected that brain
size was linked to intelligence. German
neuroanatomist Franz Joseph Gall suggested that
organisms with a large brain relative to body size
might be of greater intelligence than those with a
smaller brain. The theory sounded reasonable enough,
but until recently a suitable method of testing this
idea had eluded scientists. The trouble is that
intelligence is particularly difficult to define,
let alone measure. "Previous attempts to establish
animal intelligence used standardized IQ-style
tests, which were unfair to certain species and out
of touch with real life situations", explained
Lefebvre. "We had to find a whole new way of
measuring intelligence". By recording the ability of
animals to find solutions to problems in a natural
setting - to innovate and learn in the wild -
Lefebvre developed a new, unbiased method of
measuring their intelligence.
In 1994 Lefebvre started to
collate reports of wild bird innovation to
investigate the relationship between brain size and
intelligence. "Birds are incredible innovators",
explained Lefebvre. "People love to bird watch and
record these behaviors." Nowhere is this more
apparent than in Britain, where membership to the
Royal Society for the Protection of Birds is nearly
four times greater than membership to Tony Blair's
ruling Labor Party. The scientific journal British
Birds devotes numerous pages to observations of
novel bird behavior provided by amateur enthusiasts
and scientists alike. Much like the game of cricket,
the British love of birds spread through many of the
Empires' former colonies. Consequently, examples of
innovation in birds can be found in great abundance
from around the world. Lefebvre has documented over
2000 new innovations from more than 500 different
bird species. Interestingly, feeding behaviors are
the most reported innovation. One of the most
commonly cited examples of a feeding innovation is
that of the European blue tit; In Britain, where
milk is delivered to household doorsteps, blue tits
are commonly found opening the tin foil bottle caps
in order to feed on the cream. Other examples may be
less familiar but equally, if not more remarkable.
For example, in New Zealand, house sparrows gain
access to cafeteria food supplies by triggering the
motion sensor that opens the door. In Australia,
skua feed alongside elephant seal pups on the milk
from their lactating mother. Greenback herons can be
found around the world using bread and insects as
bait in order to catch fish. Using innovation
reports like these, Lefebvre has been able to rate
bird groups according to their intelligence and
confirm a positive correlation between brain size
and intelligence in birds. "The common crow has one
of the highest brain to body size ratios" said
Lefebvre. "In human IQ terms it would be around
135". In contrast the IQ of the average person is
100.
So what are the world's
most intelligent birds? Woodpeckers rank high in the
bird intelligence pecking order. As an example of
their innovation, take the gila woodpecker found in
the south west USA and Mexico that fashions a wooden
scoop out of tree bark to carry honey home to its
young. Also high in intelligence are birds of prey
(e.g. hawks, eagles and falcons). Bald eagles in
northern Arizona have discovered that dead minnows
lay frozen under the surface of ice-covered lakes.
On lakes where the ice is thin, eagles can be found
chipping holes in the surface. This alone is not
enough to earn them their meal however; the eagles
then jump up and down on the surface of the ice,
using their body weight to push the minnows up
though the holes. The most intelligent bird group
according to Lefebvre's research are crows. The
Japanese carrion crow exhibits a remarkable
behavior that demonstrates why this bird is at the
top of the "bird brain" charts. At a university
campus in Japan, carrion crows have developed a
unique feeding innovation that exploits human
technology. Carrion crows perch at traffic
intersections and patiently wait for the red light.
When the vehicles come to a stop, the crows spring
into action - they fly down to the cars and place
walnuts under the tires. These crows are smart
enough to have figured out that the simplest way to
open a nut is to get someone else to do it for you!
