Male peacocks have tail feathers that make up 60% of their body length. During the mating season they fan their tails and shake these feathers in front of females. Females evaluate the tail-shaking behavior as part of selecting their mate. Which behavior is most likely to have been the original behavior that, through natural selection, resulted in this mate choice behavior of tail shaking?
1. head movement to make eye contact
2. involuntary muscle contraction such as shivering
3. sound production with the larynx flight
4. grooming feathers with the beak