Various hypotheses seek to explain why females would select for one call over the other.

Two males and four females, selected from Ryan's radio listenership, partook in the television show.

That is, males will claim an area as a territory and females select the best territories to roost and mate in.

The females visit the arena and select the male of their choice, mate with him and then depart to rear the young on their own.

Eventually all the males will have the characteristics that the females are sexually selecting for, as only those males can reproduce.

In this case, usually the males display, and the females select.

The females select their mate based on the quality of the cavity and the food located inside.

Therefore, females are actually selecting for high genetic variance.

For female mammals, with a relatively slow reproduction rate, sexual selection leads to choosiness, which helps females select higher quality mates.