For some animals, parenting lasts a lifetime. For others, it ends before the offspring are even born.

A sea turtle digs a nest in the sand, lays her eggs, covers them and returns to the ocean. Weeks later, the hatchlings emerge and make their way to the water without ever meeting their mother. Many butterflies follow a similar strategy: the female chooses a plant that will provide food for her caterpillars, lays her eggs and leaves.

An octopus takes a very different approach. After laying her eggs, a female may spend weeks or months guarding them, cleaning them and circulating oxygen-rich water over them. During this period, she typically stops eating. In most octopus species studied, the mother dies around the time her eggs hatch, and the young begin life on their own. Some deep-sea octopuses take this devotion to an extreme: one female in the deep sea was observed guarding her eggs for more than four years.

Birds often continue caring for their young after they hatch. American robins spend about two weeks incubating their eggs and another two weeks feeding the nestlings. After the young leave the nest, the parents continue feeding and protecting them while they become stronger flyers and learn to find food for themselves.

For some mammals, childhood lasts years. Young orangutans stay with their mothers for about seven or eight years, learning what to eat, where to find it and how to move through the forest. Elephant calves also spend years dependent on their mothers and other members of the herd, gradually learning the social and survival skills they will need as adults.

And then there are orcas. In some populations, sons and daughters remain with their mothers throughout their lives. Mothers may continue sharing food with adult sons, and even after females stop having calves themselves, their experience can help their families survive.