object permanence is a fancy phrase we use in child psychology. Basically, it means that they realize objects are there even when they can't see them. It's why babies develop separation anxiety at about 9 months, because they realize that mom is gone, instead of just thinking she has ceased to exist.
Parrots need to have a sense of object permanence before they can search for food, because they realize that it exists even though they can't see it.
There, your parrot psych for the day.
-Hannah