Small birds will often mob large predatory birds such as owls and hawks. This behavior involves the smaller birds gathering or flying near the larger bird, calling loudly, and even striking the larger bird, and may result in the larger bird leaving the area. This behavior is risky for the smaller birds but is commonly seen. From this description we can reasonably conclude that:
a. birds are not intelligent enough to know that the larger bird is dangerous
b. this behavior is clearly maladaptive and should be eliminated by natural selection
c. there must be some advantage of this behavior, such as protecting their chicks, that makes the risks worthwhile
d.These birds must have learned this behavior by operant conditioning

Predatory birds such as owls and hawks are a major danger to small birds such as sparrows, for example. Animals are aware of the dangers that surround them, so little birds know that facing predatory birds is not a pleasant situation and extremely dangerous. However, animals have an instinct to fight for their survival and the survival of their chicks.

Small birds only face predatory birds when there is a situation that provides an advantage in this behavior. This advantage has to be large enough to overcome the risk of death the predator provides. Small birds may face predators to protect their chicks, for example.