Final answer:
The mother duck defends her ducklings by pretending to have a broken wing, distracting predators away from her young, which demonstrates altruistic behavior and increases her genetic fitness.
Step-by-step explanation:
The mother duck defends her child from predators by creating a distraction such as pretending to have a broken wing. This act of sacrificing potential safety is known as altruistic behavior. By risking harm to herself, the mother duck draws the predator away from her ducklings, greatly increasing their chance of survival, which in turn boosts her overall genetic fitness. This behavior is not just limited to birds, but is a common trait among various species for caring for the young in the animal kingdom.