The Velocity of Love. The Role of Female Choice in Salmonine Reproduction

The role of female choice in salmonine reproduction is discussed. Behaviour is explained as the outcome of the individual's internal motivation and the external stimuli received. Nest depth is identified as the key stimulus to induce egg release. The velocity by which females reach that depth is proposed to be an indicator of their choice. Long‐term data from different salmonines are used to construct a theoretical ‘Index of Choice (I)’ based on the nest building velocity. I then present the hypothesis that female choice selects for male aggression based on two lines of evidence: the artificial removal of female choice in a wild salmon population and the spawning habits of two non‐nest building salmonid species.