It is always interesting to
see other species using tools to get what they want. This usually means food,
of course. It seems reasonable to see primates doing this, but birds are
becoming well known for using tools too. New Caledonian crows are the favorites
to be tooled up and, of course, we like to test their competence.
The latest test that
they’ve had to pass is the one set up by Æsop
in the 2nd Century CE. Specifically from the Crow and the Pitcher
story in which the canny crow dropped stones into the pitcher to raise the
water level up to beak reach level. Taylor et al reported this new study in
yesterday’s edition of PLoSone (1).
The participants were wise
old birds: Caesar, Laura and Bess, and two young adolescents: Mimic and Pepe.
Unfortunately Bess was a bit flighty and Mimic hopped into the breach. Unlike
in Æsop’s example, the birds weren’t thirsty.
There was some tasty morsel lying tantalizingly on a little raft that was out
of reach down a tube.
They very quickly worked
out that dropping stones into the tube raised the water level. Moreover, they
preferred to use larger stones, which, of course, meant they got the food with
fewer repetitions. At this point the bird-psychologists got sneaky and gave
them a choice of two tubes with rafts. The first was filled with water and the
second was filled with sand, but our crafty crows decided that water was a
better bet if they wanted to eat.
By this time our team had
got into the habit of using large and heavy objects to get their just
desserts. So what did the psychologists
do? They changed the game. They put the food in a deep channel and offered the
team thin sticks, thick sticks and a piece of string to dig the food out. The
string was picked up and tossed casually aside with proper contempt. They also
liked the thinner sticks to the thick ones.
Clearly, our team was well
brought up to have delicate and refined table manners.
Please note that this
blog is migrating to
in 17 days.
