Microlophus bivittatus

The San Cristóbal lava lizard (Microlophus bivittatus) is a species of lava lizard endemic to San Cristóbal Island in the Galápagos Islands. The species is commonly attributed to the genus Microlophus but has been attributed to the genus Tropidurus. They are currently under threat by invasive cats on the island.

Reproduction 
Lava lizards have a breeding ritual where males will compete via head bobbing to avoid physical conflict. Research has found that head bobbing achieves a greater response when the response is immediate as compared to a 30-second delay. Larger males will receive greater aggression from other males and greater assertive responses from females. There is no current data that supports ecological competition is higher between same sex individuals however.

References 

bivittatus
Category:Endemic fauna of the Galápagos Islands
Category:Lizards of South America
Category:Reptiles of Ecuador
Category:Reptiles described in 1871