Microlophus bivittatus (Peters, 1871)

Common Name and Endemicity

Microlophus bivittatus, commonly known as the San Cristóbal lava lizard, is a species of lava lizard that is endemic to San Cristóbal Island in the Galápagos Islands.

Taxonomic Classification

While this species is most commonly classified within the genus Microlophus, it has also historically been placed in the genus Tropidurus.

Threats

It is currently threatened by invasive feral cats living on its native island.

Evolutionary Relationship

This species is closely related to Microlophus occipitalis, which evolved as a radiation event originating from M. bivittatus.

Breeding Ritual

Like other lava lizards, the San Cristóbal lava lizard follows a specific breeding ritual: males compete with one another through head bobbing behavior, rather than engaging in direct physical conflict.

Head Bobbing Signal Timing

Studies of this behavior have found that head bobbing elicits a greater response when the response to the signal occurs immediately, compared to when the response is delayed by 30 seconds.

Conspecific Response to Male Size

Larger males receive higher levels of aggressive behavior from other males, and more assertive responses from females.

Same-Sex Competition Research Status

Currently, there is no available data to support the hypothesis that ecological competition is stronger between individuals of the same sex.