From San Francisco, at the Experimental Biology 2006 meeting
Animals endure famine—some more successfully than others—by cannibalizing their own tissues. Rattlesnakes, among the champions, can survive more than 2 years between meals.
To understand how, evolutionary physiologist Marshall McCue of the University of Arkansas in Fayetteville starved 2-year-old rattlers for more than 5 months and measured changes in their bodies. To his surprise, he found that although the snakes continued to move about and even to grow, "they undergo an almost hibernation-like drop in metabolic rate." In this state, the snakes consumed just 20 percent as much oxygen as when they were well fed, says McCue.
After initially putting Western diamondbacks (Crotalus atrox) on a regular feeding regimen of one mouse every 2 weeks for 6 months, McCue suddenly gave them only water. He reports that the animals relied largely on stored fats to survive.