Definitions of parental behavior differ, but Shine points out that mother snakes seem to go to some trouble for their offspring. For instance, python moms will often stay coiled around their pile of eggs for about 2 months, even though they haven’t had anything to eat for 6 or 7 months. At first glance, it might seem hopeless for a cold-blooded animal to try to incubate its eggs. When the temperature drops sufficiently, though, the python shivers, thereby warming the clutch with heat derived from muscle activity.
Many rattlesnakes and their pit viper cousins don’t lay eggs but instead give birth to ready-to-wriggle offspring. Back in the Chiricahua foothills of Arizona, the black-tailed rattler mother that so excited Hardy and Greene stayed near her youngsters and the sheltering rocks of the birth site for more than 9 days. The scenes that the researchers described in 2002 might apply as well to a mother dog and her pups.
On day 4 after the birth, Hardy observed superfemale 21 near the birth site as five of her newborns crawled around. They had worked their way out of the shelter’s entrance, over the mother’s body, and a little way into the surrounding grass. An hour later, several youngsters had piled on top of her. When one wriggled over her head, she tolerantly rearranged her coils.
Thus, the days went by with the family basking just outside its rocky den. About 9 days after birth, the little snakes shed their skins as their mother watched from a few inches away. The youngsters then disappeared, presumably crawling off on their own.
Greene and Hardy’s detailed monitoring of black-tailed rattler life had convinced them that the females typically don’t eat during winter hibernation or the spring pregnancies that follow. Greene paints a heroic picture of the mother, who further delays her return to hunting. “She hasn’t eaten for about 10 months, but she stays around for 10 more days,” he says.
He and Hardy have since observed similar behavior in several females.