“When I first started watching the monkeys, I thought the females were so mean,” said Ms. Zahed, who is working on her doctorate. “The infants would try to get food, to get whatever the mother had, and the mom would grab it back and go away. The dad, on the other hand, would give up his food and let the infants get away with anything.

“Then I got pregnant with my second child while I was still nursing the first,” she added. “Then I understood. You do get grouchy.”

In contrast to the obvious link between paternal care and offspring welfare seen in tamarins and marmosets, a male Barbary macaque’s fascination with infants can look less than kid-friendly. Once abundant throughout North Africa, but now limited to forest patches in Algeria and Morocco, these monkeys live in troops of some 30 animals, a mix of related adult females and unrelated adult males. Females give birth in the spring, and Dr. Fischer said, spring “is high season for infant dealing.”

Within days of being born, every infant is fair game for male pawings. “A male will approach a mother slowly,” Dr. Fischer said, “seize the moment, and take the infant.” He will carry the infant under his belly, or in his arms, and he’ll advance toward one or two other males and start to make nice.

“If they don’t have an infant, they can’t interact,” Dr. Fischer said. “There would be too much tension between them.” A male may hold on to an infant for hours at a stretch. If the baby starts to cry, he may take it back to the mother for a feeding, all the while hanging on to the ankle of his precious networking tool.

The researchers initially assumed that baby handling might have a tranquilizing effect on the males, but on measuring the macaques’ hormone levels, they found the opposite: carrying an infant caused a male’s stress hormones to spike. The scientists now propose that the males use the infants as “battle symbols,” as Dr. Fischer put it, “to show other males that they can bear the stress.”

What better proof of a worthy ally, who will not wilt come breeding season  when males must form coalitions to monopolize fertile females and help spawn the next generation of fuzzy handheld devices?