21. Grunts are commonly heard from hungry young and from adults in their courtship display . 22. It also has an elaborate courtship display and a variety of loud mating calls. 23. Male courtship displays include elaborate vocalizations, which the female responds to with nest building. 24. While the courtship display hypothesis speaks to sexual selection and competition, even between females. 25. Visual cues are important for males to find females, and courtship displays can be elaborate. 26. In courtship display on membranous neck sacks and the drum-like call of the greater prairie-chicken. 27. Biological ornaments are used in courtship displays in many species, especially insects, fish, and birds. 28. Seesawing, the second courtship display , involves repetitively alternating lowering and raising the head and tail. 29. These flashes from the wings may attract several males that engage in aerial courtship displays . 30. During breeding season males perform courtship displays such as horizontal figure eights around the nest.
