The concept of multi-generational families living together is not common in the animal world. Most mammals don’t live very long after they have finished passing along their genes to offspring, or they move on after raising their young. But there are a few notable exceptions -- in addition to humans, of course. There is an evolutionary role for some grandparents living in the families of elephants, certain types of monkeys, and whales. Studies have shown that in some species, grandmothers can influence natural selection long past their reproductive years. Grandfathers, however, rarely play any role in animal families. Older males typically focus only on producing more offspring.
A place for Nana:
- Grandmother langur monkeys, for example, aggressively defend the family's infants against attacks from predators. They also help groom the young, and intervene when playtime gets too rough.
- Elephant grandmas can live up to 80 years and are often the boss of the family. They know the best spots to forage for food, or to find water, and they take the lead when interacting with other elephants.
- Many whale species travel as family units, including grandmothers and their grandcalves. Older sperm whale females, for example, take care of the young while their mothers dive for food.