Interlude - Index of

Interlude
Speckled-Egg Thinking
An article about cliff-dwelling seagulls and the challenges
they face helped shape my view of human nature. Small rocks
are always falling down the cliffs and landing in the birds’
nests. That’s bad, because rocks can crack eggs and hurt
chicks, so the gulls push them out of their nests. Sometimes
eggs roll out of the nest and onto the rock ledge. The birds
naturally pull escaped eggs back into their nests.
How do the gulls decide what to push out and what to
pull in? Or to put it another way, how do bird brains identify
stones and eggs? To find out, researchers put objects with
various shapes and colors into the nests. The gulls pushed out
anything with sharp, pointy corners. They apparently identify
rocks by feel, ignoring color. Next the researchers put the
same objects outside the nest to see how birds identified eggs.
This time, the gulls ignored shape. They simply pulled in anything
with the same brown and speckled color as their eggs.
To the scientific mind, this raised an obvious question: How
would the birds respond to a brown and speckled cube? It’s pointy
like a rock, but colored like an egg. Put this evil egg into a nest,
and here’s what happens. First, the bird pushes it out, because
of the sharp corners. Then the bird pulls it back into the nest,
because of the color. Out of the nest and into the nest, all day
long. Each individual act makes sense, but repeating to exhaustion
does not. The birds can’t step back and see the big picture.
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