Why is the energy expended during kleptoparasitism often energy-efficient for the skua?

Answer

The victim bird has already done the hard work of locating and catching the prey.

The energy saved by stealing often outweighs the energy expended in harassment because the victim bird has already successfully located and caught the prey item.

Why is the energy expended during kleptoparasitism often energy-efficient for the skua?

#Videos

Skua facts: Sky Pirates | Animal Fact Files - YouTube

birdseabirdSkua