The individual time series of pre-ovulatory periods for each of the five Control (blue) and five Playback treatment (red) animals from the start of the experiment (vertical back bar) until 26 weeks thereafter. Individuals are organized vertically along the y-axis with each animal identified by an alphanumeric code. For example, the first Control individual is C1, while the last Playback individual is P5. The end of each pre-ovulatory period is highlighted with a point, as this is the time when a female can mate and become pregnant. There were 34 pre-ovulatory periods observed for the Playback group, and 17 observed for the Controls.