Once upon a time—only a few decades ago, in fact—most animal
scientists were convinced that humans were the sole creature to make and use
tools. These scholars were sure that the superior intelligence of Homo sapiens was required, in order to be
able to create and employ tools—as well as an opposable thumb to provide the
necessary dexterity. These unique human advantages are crucial, it was thought,
in order to forge a complex culture and to manipulate the environment to one’s
use through tools. We humans rule the world by dint of our big brain, our complex
instruments, and our technology (and that thumb, of course). We are alone in
our use of tools!
That prideful perception has become assigned to the trash
heap of theories, as one observer after another has witnessed and described nature’s
many other critters who intelligently fashion and employ tools. Some of the
first examples to shatter the outdated viewpoint were observations of other
primates: our chimpanzee and ape cousins. They are quite accomplished at using
sticks and twigs to extract insects from hiding places, to measure water depth
(Is it safe to cross this stream?), and for other purposes. They sharpen sticks
to use as weapons. They are also adept at using stones for cracking nuts and
other clever applications. Chimps will chew leaves to soften them and use it as
a sponge to soak up water. They watch each other, learn these tricks, and pass
them on.
Elephants will pull pieces of bark from a tree to stuff in a
small water hole, in order to maintain the hole they just dug. They move large
objects (like boulders and tree trunks) to use as stepping stools to reach
overhead objects. The will grab a stick and use it as a back scratcher. They
don’t possess a thumb at all, but have a very dexterous and sensitive trunk. Maybe
that makes up for their clumsy feet?
Now, elephants are known to be very sociable animals and are very
intelligent. But even “dumb” birds can do it. Crows cleverly manipulate sticks
with their beaks to extract insects from logs. They also drop hard-shelled nuts
on human-built pavement, wait until passing cars crush them, and then retrieve the
nutmeats. Ravens carefully select twigs, which they then use for toys.
Moving to aquatic animals, octopuses collect sunken coconut
shells and move them to a new location, to build themselves a protective shelter.
That’s not only a tool-building skill, but also a good example of planning
ahead. Some species of fish employ rocks to crack the hard shells of bivalves.
And let’s not forget those clever dolphins. They blow bubble rings and play
with them, use conch shells to trap fish, and stick a sponge on the end of
their sensitive noses to protect them from abrasions, as they forage along a
rocky sea bottom.
What is common in all of these examples of tool building is
they are exhibited by what are considered to be Earth’s more intelligent animals.
In fact, these examples were all wild
animals. Scientists have known for some time that animals in the wild are
smarter than their domesticated cousins. When an animal is bred for tameness,
its brainpower suffers. It seems to give up intelligence for the safety of
human companionship. So how about a domestic example of animal tool use? More
on that next time…
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