Discovery that mice are an important food for Barrens wolves

The discovery that mice were an important food for the wolves at Wolf House Bay overturned Farley Mowat’s assumption that a wolf’s diet depended on large game. With the caribou gone for the summer, the wolves nevertheless stayed in good condition and raised their pups. Close observation of Angeline revealed a small-prey hunt that had been easy to overlook; further evidence showed how the adults brought that food to the den and how the wolves’ diet extended beyond mice.

The Summer Food Puzzle

Toward the end of June, the last migrating caribou herds passed Wolf House Bay on their way to summer range in the high Barrens, roughly two or three hundred miles to the north. Their departure left the wolves with hungry pups to feed but no caribou nearby. Farley Mowat could identify no other abundant prey that seemed adequate for three adult wolves and four young. Hares were scarce and difficult to catch, birds could fly away, and fish seemed unlikely to him as a major food source.

The wolves’ condition made the lack of an obvious food supply harder to explain. The two males went hunting each night and returned each morning, yet Mowat never saw them bring anything home. The family did not appear to be starving; it seemed, from his limited view, to be living without a visible larder. Concerned, he baked five loaves of bread and left them beside a hunting path. The wolves rejected the offering. The failed experiment did not solve the puzzle, but it emphasized how little Mowat understood about what they were finding on their nightly hunts.

Rodents and Angeline’s Hunt

As June waned into July, the sphagnum bogs around Wolf House Bay became crowded with small rodents. Lemmings were especially numerous, while red-backed mice and meadow mice entered Mike’s cabin and threatened its food stores. Their presence was not merely incidental to Mowat’s camp: it pointed to a prey source abundant in the same landscape where the wolves were hunting.

The turning point came when Angeline left the den after rousing Uncle Albert, who stayed behind with the pups. She went to the bay to drink. Afterward, a small flock of Old Squaw ducks landed nearby, and Angeline behaved in a way Mowat initially misread as play. He kept her in view with his telescope as she crossed the muskeg on her return. Moving slowly, she began to pounce at intervals, snapping up prey that Mowat could not at first see. On one missed pounce, he recognized a mouse in her jaws. By the time she had eaten about twenty-three mice, he could no longer dismiss the activity as casual snacking: together, the small prey amounted to a substantial meal.

The important evidence was the sequence, not simply the presence of mice. Angeline had left the pups with an adult caregiver, gone out across the muskeg, and returned after feeding. Her repeated, directed pounces showed Mowat that she was hunting, while the number of mice consumed demonstrated that the prey could matter nutritionally even though each animal was small.

From Observation to Explanation

Mowat gradually connected Angeline’s behavior with the healthy condition of the wolves and the absence of caribou from their summer range. He concluded that the Wolf House Bay family lived largely, and perhaps almost entirely, on mice during this period. He extended the inference cautiously: other wolves in the Keewatin Barrens raising families beyond the summer caribou range could also rely heavily on rodents. The conclusion did not rest on one isolated sighting alone; it explained how the animals could continue feeding themselves and their pups when the large herds had moved away.

The discovery also made sense of behavior Mowat had previously observed without understanding. George and Uncle Albert returned from hunting and went directly into the den. He had not suspected that they were regurgitating food already partly digested. Later in the summer, after the pups had left the esker den, he saw an adult wolf regurgitate a meal for them. This supplied a practical answer to the question of how adults could transport many mice back to the family: the prey was carried in their stomachs rather than externally.

Corroboration and Wider Diet

Ootek, whom Mowat came to know as a close friend and an accomplished naturalist, helped explain the transport of the mice. His knowledge also broadened the picture of wolf feeding. He confirmed the role of mice but described other foods as well: wolves ate many ground squirrels and sometimes appeared to prefer them to caribou. He also reported watching wolves fish for Northern pike in narrow marsh channels during the spring spawning season, and described them catching suckers on their spawning runs. These accounts placed the mouse discovery within a flexible, seasonal diet rather than making mice the wolves’ sole possible prey in all conditions.

A later examination of wolf scat provided another line of evidence. About 48 percent of the samples contained rodent remains, mainly fur and incisor teeth. Other identifiable material included caribou hair and bone fragments and a few bird feathers. One sample also contained a badly corroded brass button bearing a recognizable anchor-and-cable design; Mowat noted its presence but did not treat it as proof that a wolf had eaten a sailor. The scat findings supported the importance of rodents while also preserving evidence of a varied diet.

Significance

The episode changed Mowat’s understanding of what wolves could live on and how they provisioned a family. Before observing Angeline, the absence of caribou seemed to leave the wolves without a plausible food supply. The hunt disclosed a plentiful prey base in the bogs, while the adults’ regurgitation explained how small, numerous catches could reach the pups. The discovery therefore joined landscape, behavior, and family care in a single explanation.

It also exposed the limits of assumptions shaped by the image of the wolf as a hunter of large game. At Wolf House Bay, the animals’ survival through the summer depended not on a dramatic pursuit of caribou but on repeated hunts for small rodents and a means of carrying those meals back to the den. Mowat’s conclusion emerged from sustained observation, then gained support from Ootek’s knowledge and the scat analysis. Together, these sources made the mouse diet a concrete account of wolf adaptability rather than a guess based on the empty caribou range.