deep cooperation: the mammalian equivalent of honeybees?

nytimes |  Researchers have known for some time that wild dogs are exceptionally social and civic-minded. Among most group-living carnivores, big adults feed first, gulping down the choicest organs and leaving junior diners to scrounge through gristly leftovers. Among wild dogs, said Patrick R. Thomas, the curator of mammals at the Bronx Zoo, “it’s the exact opposite.”

“The adults let the puppies feed first,” he said. “It’s very peaceful to watch.” 

For puppies too young to leave the den, or for injured pack members unable to hunt, hale-bodied adults go further, provisioning the needy by regurgitating a portion of a recent meal.

Researchers have also known that wild dogs are so-called cooperative breeders. In any given pack of closely related animals, a single male and female will do the bulk of the reproducing, while the other half-dozen or so adults serve as guardians, babysitters, even wet nurses for the alpha pair’s pups. Family is family, after all. 

Yet researchers continue to be impressed by the depths of the dogs’ self-sacrificing behavior. In one recent study, Dr. Creel and his colleagues determined that the bigger a pack grew, the more efficiently it hunted and the greater the number of offspring it raised. However, the researchers were startled to see that not everyone benefited from the swelling ranks. 

“Big packs with lots of offspring turn out to have poor adult survival,” Dr. Creel said. The cost of regurgitating food for a surging number of pups, it seemed, exceeded the advantages of bringing down more prey. As a result, nonbreeding adults in big packs would gradually become malnourished and end up dying at a somewhat younger age than their peers in smaller clans. 

The dogs are “true altruists,” essentially willing to shorten their lives for the sake of the hive, Dr. Creel said, adding, “They’re even further along the line of evolving into the mammalian equivalent of honeybees than we thought.”