How do penguins use stones in their courtship behavior?

In the context of reproductive behaviour in zoology, the use of stones is a specific nesting behavior rather than a direct component of courtship displays.

Among Adélie penguins, unpaired males return to their breeding colonies in late September to build small nests out of stones. While these nests are essential for the breeding process, the actual courtship behavior—known as the "ecstatic display"—consists of physical actions such as neck arching and beak thrusting performed by the male to attract a mate after the females arrive at the colony.1

Therefore, while the collection of stones is a foundational part of the male's preparation for the breeding season, it serves to establish the nesting site rather than functioning as a courtship display itself.1