A polar bear mom rests after nursing in Wapusk National Park in Manitoba, Canada.
Polar bears mate in the spring but don't become pregnant until the fall. Then, only those females who've successfully fattened up over a summer of hunting will begin to bear young.
During those months of plenty, a bear may gain more than 220 pounds, and mothers need every bit of those reserves when it's time to den. Depending on where in the Arctic they call home, polar bear moms may remain in their snowy dens for up to eight months without eating or drinking.
Cubs, often twins, spend their several months in their den, enjoying their mom's high-fat milk.
Moms dote on their cubs for two to three years, protecting them from threats including male polar bears. They also teach them the skills needed for life on the ice, including how to swim, hunt, and prepare dens for their own future families.
Some mothers lay eggs, in treetops or on the seafloor, while others labor through long pregnancies and live births. Many moms are on their own, but a fortunate few get help from babysitters or nursemaids. Some moms have dedicated co-parents, but others have to go it alone—or even contend with infanticidal killers.
Mother-child bonding runs the gamut of relationship styles. Lion moms may live with their daughters for life, harp seals must cram every bit of their maternal care into less than two weeks, and many lizards never meet their offspring at all. Some mothers, like octopuses, sacrifice their lives to give the next generation its start.
Just keeping babies alive long enough to reach adulthood is a challenge. But moms also have to teach their young how to be a monkey, a cheetah, a whale, or a falcon. (Read how animal mothers remind us a lot of our own.)
“Many species seem to recognize that the young really don’t know what they are doing,” says animal behavioralist Jennifer Verdolin, author of the book Raised by Animals, “so they are given a kind of grace period to learn.”
One thing that most all animal mothers have in common is sacrifice; nature doesn’t make it easy to nurture the next generation. This photo gallery celebrates some of those amazing animals who, in their own unique ways, dedicate themselves to motherhood.