Moms give up sleep, solitude, serenity for love

By Dr. Beth Leermakers

In the animal kingdom, child rearing typically falls to females — especially among mammals, where male involvement in caregiving is rare. Like human mothers, mammalian moms wear many hats. They are:

Milk providers. Lactation and nursing are energy-intensive tasks that continue for years in some species. Orangutan mothers nurse their young for six to eight years — and sometimes longer. A grey seal mother transfers more than 18,000 kcal to its pup each day over an 18‐day lactation without acquiring any food (energy) herself. This is roughly the daily energy requirement for nine adult humans (based on an average of 2,000 kcal per day). 

Elephants have the longest gestation period (18-22 months) of any mammal. An elephant mom feeds her newborn calf 2.5 gallons of milk per day, increasing to more than five gallons per day at the calf’s first birthday. For comparison, a human mom usually produces about 30 ounces (.2 gallon) of milk a day to feed her baby. Some elephant calves suckle occasionally for up to 10 years. 

Protectors. For many animals, survival depends on being able to avoid predators. Mother cheetahs hide their cubs in their den for six to eight weeks, moving from den to den many times to protect their young from lions, hyenas and leopards. If her cubs are discovered, mom fights off the predators, but she rarely wins, given that cheetahs are built for speed, not fighting. 

With their fiercely protective nature, grizzly bears are the reason “mama bear” is used to describe protective mothers. While other bear species may abandon their cubs when danger lurks, a mama grizzly bear will fight off any creature — including male bears — who tries to harm her cubs. 

Mother bears must protect their cubs from male bears. If a mother loses her cub, she soon goes into heat, so a male that kills her cub has a good chance of impregnating her. Female grizzly bears and Scandinavian brown bears move away from male bear territory after giving birth. 

Researchers discovered that brown bears in Sweden that successfully raised their cubs lived close to human settlements. Adult male bears avoid towns because people are likely to kill them. The researchers concluded that the mother bears were using people as a shield to protect their young, following the principle of “the enemy [people] of my enemy [male bears] is my friend.” 

Teachers. Bottlenose dolphins start teaching their young to recognize mom before they’re even born. Dolphins teach their babies a “signature whistle”— unique sounds made by dolphins to identify each other — from two weeks before birth until two weeks after. 

Researchers think dolphin moms sing these “lullabies” to imprint their offspring so they recognize their mother and don’t get lost or stolen by another female in the pod. During the first two weeks of the calf’s life, the other dolphins in the group don’t produce their signature whistle very often, presumably staying quiet to prevent the calf from imprinting on the wrong signature whistle. But after the mom stops repeating her whistle, the other dolphins became more vocal. 

Orca whales are among the few species known to actively teach their young (and each other) different skills. Biologists observed four female Orca whales off Antarctica teaching three calves complex hunting techniques, including wave washing (i.e., creating a powerful wave to wash seals off an ice floe), tipping the ice, bubble blowing to flush the seal from under the ice and taking hold of the seal by its hind flippers to prevent injury from its teeth. In one film clip, a female orca was the head teacher, demonstrating how to pull the seal off the ice by its tail, while the calves watched and learned. The whale let the seal escape and, after it jumped back on the ice, the calves took turns practicing the technique. 

Cheetah moms start teaching their cubs to hunt when they’re about five months old. Mom begins releasing her captured prey for the cubs to practice chasing and re-catching, but mama still must perform the kill. The mother and cubs hunt together until the cubs can initiate their own hunts and kills (usually at 12 months).

This Mother’s Day, we honor the incredible human moms who give up sleep, solitude and serenity to lovingly care for their two- and four-legged kids. Wishing all moms a joyful and well-deserved celebration!