Researchers in the Serengeti were quantifying the hunting behavior of female cheetahs (Acinonyx jubatus). They measured the proportion of the day spent hunting, hunts started per hour, proportion of hunts which were successful, and time to complete a hunt. They recorded the age of the cheetahs' cubs if any, and how her hunting behavior changed with the age of the cubs.
Cheetahs with no cubs don't have to spend as much time hunting. Once they have cubs in the lair or just out of the lair, they have to spend more time hunting to feed those children.
But there's another factor that goes into time spent hunting. I will remind you that cheetahs don't pair up, so these female cheetahs are single ladies with no babysitters and they can't even get their own mothers to help.
The cheetahs whose behavior confounded the measurement of hunting time had young cubs, nursing but out of the lair. Fluffy, playful, delightful cubs full of nonstop energy, with exciting new teeth.
When their mothers hunted these cubs either stayed behind or followed her for a short distance. Then they would sit and watch their mother advancing toward the prey, not coming forward unless she called them (to share the gazelle she'd just caught, say). Cubs know how to do this. They watch carefully as their mother stalks the prey.
A cat stalking its prey often creeps forward, stops and crouches in place for a while, creeps forward some more when the prey isn't looking, stops again, and so forth. The researchers timed all this. To their surprise, the mother cheetahs were also taking naps. Creep, creep, crouch, snooze, creep, creep, crouch, snooze. Sometimes they'd sleep for ten minutes at a time in the middle of a stalk. Presumably, the cubs, lacking binoculars, just thought their mother was being extra sneaky.
I think the researchers sympathized. “Freed of nursing attempts and being played upon, a mother had a chance to close her eyes,” wrote T. M. Caro in Cheetahs of the Serengeti. “Prey often wandered off as a consequence...”
Any caretaker of youth can guess how those cheetahs feel. “I would kill for a nap. A nap and a glass of wine. A nap and a glass of wine without being chewed on and FIVE MINUTES CONVERSATION ABOUT SOMETHING BESIDES MR. IMPALAHEAD.”