Data from: Intruder color and light environment jointly determine how nesting male stickleback respond to simulated territorial intrusions

Variation in male nuptial color signals might be maintained by negative frequency-dependent selection. This can occur if males are more aggressive towards rivals with locally common color phenotypes. To test this hypothesis, we introduced red or melanic 3D-printed model males into the territories of nesting male stickleback from two optically distinct lakes with different-colored residents. Red-throated models were attacked more in the population with red males, while melanic models were attacked more in the melanic-male lake. Aggression against red versus melanic models also varied across a depth gradient within each lake, implying that the local light environment also modulated the strength of negative frequency-dependence acting on male nuptial color.