Question

A male stickleback fish will attack other male sticklebacks that invade its nesting territory, it only attacks males with the red belly. why has natural selection favored this

Answer 1

flatwing males favored by natural selection. behavior: a male stickleback fish attacks other male sticklebacks that invade its nesting territory. proximate cause:red belly of intruding male acts as sign stimulus that releases aggression in male sticklebacks.