Which of the following is an example of a learned behavior?
birds scattering at the sight of a hawk
birds returning to a backyard bird feeder
birds singing to establish their territory
birds competing for food in the feeder

I believe that the answer would be the first one with the hawk. They have learned from previous experience not to trust the hawk because it could kill them. I am unsure about this, because the second looked like it might work, too. The others do not seem like correct answers to me.

That would be a working theory.