"Smart Parrot" joke

This
guy goes to a pet shop to buy a parrot. There he sees
a parrot with a red string tied to its left leg and
a green string tied to it's right leg. He asks the owner
the significance of the strings.
"Well, this is a highly trained parrot. If you
pull the red string he speaks French; if you pull
the green string he speaks German," replies the
shop keeper.
"And what happens if I pull both the strings?"
our curious shopper inquires.
"I fall off my perch you fool!!" screeches
the parrot.