The strong sociability of the Ethiopian wolf actually puzzled researchers when they launched their first major studies here in the late 1980s. Since Ethiopian wolves generally hunt alone, "it didn't make sense," Randall says. "Why live in a pack if you're not going to hunt and eat together? Why help raise the offspring of somebody else?"

An answer came after researchers inventoried the rodents available to each pack in their small, two-to-three-square mile territories: It was largely a matter of ensuring the size of their range. "They live together so they can defend an area with enough rodents so that everybody can eat and feed the pups," says Randall. That's why the morning patrols are so important to the wolves. They are, in essence, guarding their grocery store.

Breakfast doesn't come easy, judging from the number of failed stalks and leaps the male we're watching has made. He's chosen an area favored by the giant mole rat, a hefty rodent with eyes protruding from the top of its head like two periscopes. The rat feeds by making short, sudden lunges from its burrow to grab fresh grasses and plants. And it's in those few brief moments when the rat is at the surface that the wolf must act.

"The wolf's hearing is very acute," Randall says, as the male cocks his head from side to side, listening to the rustling of rodents below ground. "I'm sure they can hear the rats getting ready to surface."

Suddenly, a mole rat pops up and begins its busy back-and-forth shuttle. The wolf folds his tall frame into a crouch and crawls forward, his tail swishing like a cat's. He holds still for another second, then makes a quick dash and leaps into the air. When he comes down, his front paws slam the mole rat's burrow and he shoves his snout deep into the earth, biting dirt and grass—but not rat. Once again, he's missed his meal. Randall laughs. "It takes the young ones a while to get the hang of this."

Randall has another pack to check on that afternoon, one called Garba Guracha. It was in their territory that she found the dead wolf. Randall doesn't know if the wolf was from the Garba Guracha pack or another one nearby, and now she or another researcher checks up on the Garba Guracha wolves daily. "Some of them look sick," she says. Still, the dominant female is lactating, a sign that there are pups.

Over the next few days we return to Garba Guracha several times but never do find the den. We revisit Quarry pack, too, and spend time at Batu pack's den, watching their pups fight over old rat bones and sticks and bounce over the frosty grass to tackle their babysitter. No more dead wolves turn up, and at the researchers' camp the mood begins to lighten.