Final answer:
When a killdeer's nest is approached, the killdeer exhibits display behavior by pretending to have a broken wing. This behavior can increase the fitness of the killdeer by protecting its offspring from harm.
Step-by-step explanation:
When a killdeer's nest is approached, the killdeer typically performs:
4) It flies away.
Killdeer birds are known for their distinctive behavior when their nests are approached. Instead of confronting the intruder aggressively or attacking, they often resort to a distraction display. Killdeer may feign injury by pretending to have a broken wing, luring potential threats away from the nest to protect their eggs or chicks. This behavior aims to divert attention from the nest's location by drawing the intruder's focus towards the seemingly injured bird. The killdeer will fly away or run a short distance, trying to lead the intruder away from the nest without directly attacking or defending it.