While the Santa Catalina Island rattlesnake is a largely nocturnal snake (1), this can vary depending on the time of the year. During spring, when temperatures are a little cooler, the Santa Catalina Island rattlesnake can be observed crawling about during mid-morning as well as at night, while during the heat of summer, this snake is rarely seen out during the day, possibly spending most of the daylight hours in a burrow (2). Unlike many rattlesnakes, this species is known to be an agile and capable climber. It can move rapidly across the ground, and then swiftly climb into vegetation, to escape danger or to pursue prey (2). It was once thought that its climbing ability, as well as lack of functioning rattle, was an adaptation to eat birds (2). However, more recent research has revealed that the majority of this snake's diet is comprised of the Santa Catalina deer mouse (Peromyscus slevini), with the remainder consisting of lizards (3). So although this argues against the theory that the lack of a rattle is for silently hunting birds in vegetation, it could have evolved to allow the rattlesnake to hunt these partially arboreal rodents instead (3). Very little is known about reproduction in this snake. Males have been observed bobbing their heads and flicking their tongues during courtship (5), and evidence suggests that the breeding season falls between spring and early summer, with young being born in late summer to early autumn (2).