Just before arrival at William & Mary, I began a series of studies on birds that consume hard-shelled food such as walnuts or clams. Some species carry these impenetrable prey items high into the sky so that they will shatter on the ground below.
This is a complex skill, and carrying the food items too high, or not high enough, will result in wasted energy. I have shown that crows perform this task with close to the theoretical maximum efficiency when they are adults, extending the classic work by Zach on crows and snails that kicked off the optimal foraging research revolution in the 1970's. With undergraduates at William & Mary, I have pursued this question on a local population of clam-dropping gulls to determine how young birds acquire this sophisticated behavior - through imitation, trial-and-error, or simply following a genetically-inherited set of behavioral rules.