How does a hard-working animal mum juggle the demands of a helpless baby with feeding herself and her family? For the black-and-white ruffed lemur, Varecia variegate, the answer is simple: dedicated day care.
Lemurs are our most distant primate cousins, and only found on the island of Madagascar where they’ve been evolving in isolation for some 50-60 million years. Endangered black-and-white ruffed lemurs are unusual for primates since they give birth to litters of up to three babies.
Most primate mothers manage just one at a time as their big-brained babies take a long time to reach independence, which makes them especially demanding. Varecia variegate females have an innovative solution to the problem: they make like birds and build nests high up in the canopy. These serve as communal creches for two or three separate litters, so working lemur mums can share the parenting load.
Anthropologist Andrea Baden has been investigating this practical solution to primate childcare for the last five years. It’s not an easy task as their lives are played out high up in the canopy. But by radio tagging individuals she’s been able to decode their lofty antics.
Black-and-white ruffed lemurs are “super-weird”, she tells me as we race through the undergrowth after them. Around 20-30 individuals share a territory, but not as one cohesive group. Instead, they are “more like atoms constantly bouncing off each other”.
Despite this fluid social life females give birth all at the same time, likely triggered by a bountiful harvest. Such fruity abundance doesn’t occur every year, and the lemurs may go for six years without having babies. When they do, they make up for it by having litters. The babies are unusually helpless – blind and unable to even cling to their mother. For the first month they remain in the natal nest with mum exclusively. But once big enough, mum parks her babies in a communal nest close to a big fruiting tree.
A dedicated sentinel keeps the babies safe from harm in this high-rise nursery. As well as rescuing tumblers, babysitters also play, groom and possibly even suckle their charges. Occasionally, guard duty falls to aunts or sisters, but Baden has found that friends – both male and female – are equally, if not more, important.
Trust is key and she’s recently discovered that females will travel long distances in order to nest with reliable friends. This is borne out by how the mothers spend their free time.
Baden was surprised to discover that while some is spent gorging on nearby fruit trees, lemur mums are also spending much of their time socialising. They say, “It takes a village to raise a child”, well it certainly does if you are a black-and-white ruffed lemur.
Maim image © Getty Images