Dave relocated this courting pair of Western Diamondback Rattlesnake in mid-November. Mating activity can happen at any time with this species in Arizona, but spikes in spring and fall. If successful, the female will store sperm until the Spring. So, regardless of when mating occurs, babies are born around the same time in the late Summer.
But, this was going on just off someone’s back patio … so Dave found them a room somewhere else. Somewhere else, of course, being carefully-selected microhabitat suitable for hibernation.