Southern Pacific rattlesnakes on Santa Catalina Island display higher levels of aggression compared to mainland snakes, undermining the 'island tameness' theory.

These island rattlesnakes are more prone to bite and inject larger amounts of venom, indicating a possible evolutionary adaptation for defense in isolated habitats.

The research included a thorough and blinded examination of the snakes' defensive behavior, suggesting that adaptability in isolated species is complex and environment-specific.

Despite their aggressive defense mechanisms, Catalina Island's rattlesnakes do not pose a greater risk to humans, as they generally avoid human interaction unless threatened.

The findings emphasize the nuanced relationship between animals and their ecosystems, and the importance of considering unique environmental pressures in studies of animal behavior and evolution.