When Khali, a sloth bear at the Smithsonian’s National Zoo in Washington, D.C., went into labor in late December last year, her keepers were thrɪ.ʟ.ʟed. But soon after Khali delivered her first cub, something went wrong.
“We don’t really know what happened,” says Tony Barthel, a mammal curator in the zoo’s Asia Trail section. He and the bears’ keepers were watching Khali on a closed-circuit television. They cheered when they saw the palm-size cub come into the world.
Then, 20 minutes later, Khali—stɪ.ʟ.ʟ in labor with other cubs—bent down, not to lick her newborn, but to ᴇ.ᴀ ᴛ it. The cheers turned to gasps of ᴅɪsᴍᴀʏ.
“Our assumption is that the cub was not well, and it ᴅɪᴇd,” Barthel says.
Khali gave birth to two more cubs that day, and for the next week, she was as attentive, calm, and nurturing as a mother sloth bear could be. (She was an experienced mom, having raised two other cubs at a different zoo in 2004.)
The keepers continued to monitor her and her cubs, as they do with all bear mothers. So they were on hand when Khali ate another of her babies and turned her back on the third.
Rescuing a Baby … From Mom
Barthel and the keepers decided they had to intervene. On January 6, they retrieved Khali’s last surviving infant—a female—from her den. They rushed the cub to the zoo’s veterinary hospital, where she was found to be ʜʏᴘᴏᴛʜᴇʀᴍɪᴄ and sᴜꜰꜰᴇʀing from an ɪɴғᴇᴄᴛion.
“She was ɪ.ʟ.ʟ, with an elevated white blood cell count,” Barthel says. “We don’t know if this was the case with her other two cubs, but my assumption is they were not well.”
Shortly afterward, all the sloth bears fell ɪ.ʟ.ʟ with a ғʟᴜ ᴠ.ɪ.ʀ.ᴜ.s, which may have caused the cubs’ ɪ.ʟ.ʟness.
To save the lone cub, the veterinarians immediately trᴇ.ᴀ ᴛed her with antibiotics and placed her in an incubator to restore her body temperature. A few hours later she was happily nursing from a bottle.
And the keepers were left trying to answer what seems the ᴄʀᴜᴇʟest and most unthinkable of questions: Why would a mother ᴇ.ᴀ ᴛ her own young?
It sounds counterintuitive to evolution, but ɪɴꜰᴀɴᴛɪᴄɪᴅᴇ in the wild is well-documented, said Doug Mock, professor of biology at the University of Oklahoma and author of a book on the subject. Animal parents have limited resources to dedicate to their offspring, he said, and if the baby is s.ɪ.ᴄᴋ or weak, carnivores have been known to ᴄᴏɴsᴜᴍᴇ babies or ᴀʙᴀɴᴅᴏɴ them. Cᴀɴɴɪʙᴀʟɪsᴍ gives the mother the calories she needs to raise her healthy babies or get pregnant again.
That’s the natural history of carnivores!
Sometimes it’s the mother or father that ᴋɪ.ʟ.ʟs; sometimes it’s the siblings. Mock remembers watching a group of egret chicks peck their sibling to dᴇ.ᴀ ᴛh, while their mother stood idly by, cleaning her fᴇ.ᴀ ᴛhers.That may have been the case for Khali, Tabellario said. A ɴᴇᴄʀᴏᴘsʏ of her second cub revealed that the cub had a parasite in its intestines, which Khali may have sensed. When the keepers pulled the surviving cub from the den, she was ɪ.ʟ.ʟ too.
“It’s the most startling thing I’ve ever seen in the field,” he said. “I literally sat and watched and thought, ‘Any second, the parents wɪ.ʟ.ʟ step in and stop this.’”
When asked him how he felt witnessing this behavior: “My soul ᴅɪᴇd,” he said.
Mock has seen birds push their chicks from the nest, ᴀʙᴀɴᴅᴏɴ them, even sᴛᴀʀᴠᴇ them. In the animal kingdom, he says, ɪɴꜰᴀɴᴛɪᴄɪᴅᴇ is not about ᴘᴀᴛʜᴏʟᴏɢʏ. It’s about ensuring that the strongest offspring survive.
“It’s one of the less pleasant aspects of nature, something humans don’t like to think about. You want to think of nature as warm, cuddly and fuzzy,” he said. “We assume that other species look at offspring the same way we look at offspring… To us it seems as if (ɪɴꜰᴀɴᴛɪᴄɪᴅᴇ) must be some s.ɪ.ᴄᴋ kind of thing, but it isn’t necessarily.”