London, June 17 : The presence of a wiggling tongue-like knob on the genitals of some birds, is what helps them attract females of their species, revealed scientists from University of Chicago.
Typically, male and female birds copulate by briefly pressing together their cloacas, genital openings, which is also called a cloacal kiss.
However, scientists have for the first time spotted a muscled tongue-like projection called a cloacal tip in males of several species of Australian wrens, which indicates that it can be quite similar to a French kiss.
After studying eight species of wrens researchers led by Melissah Rowe examined the alignment of the muscles and peculated that this may help the cloacal tips to wiggle from side to side.
While she did not really seen a tip in action, she wonders that it cannot be possible that a structure made of muscle is not able to move.
They also discovered that the cloacal tips were proportionally larger in wren species where females had a tendency to mate with many partners.
Rowe said this indicated that the tip's function might be to stimulate females and encourage them to take up and retain the males' sperm.