Sceloporus cyanogenys (Sceloporus cyanogenys) rivalry is a particularly striking behavior. Males often move and bob their heads up and down when interacting with rivals of the same species. These interactions usually last only a short time. If the weaker male retreats, the conflict quickly ends. If he does not back down, the dominant male may turn sideways, flatten his body and show the bright blue color of his belly. This signals dominance toward the rival. If the warning is not enough, physical fighting may also occur. This behavior clearly shows how important body posture and colors can be in reptile communication.
