The Granite Spiny Lizards in the video below are chasing each other all over the rock. These two male lizards are fighting for dominance. Depending on space requirements and the distribution of key resources in the environment, social behavior among lizards can vary from defense of exclusive territories to the formation of dominance hierarchies. As anyone who has watched large groups of lizards is aware, increases in population density usually lead to more social interaction and heightened aggression, especially among mates. The video and photos below were taken on our Joshua Tree Adventure Tour!