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Female of the species is as randy as the male

From lizards to lobsters, females enjoy multiple-mating Lucy Cooke

It’s an odd thing to find kinship with a killer whale.

Surely there’s little I have in common with a six-ton swimming torpedo. But I share a rather unusual biological trait with this wily submarine predator. Females in both our species go through the menopause. Natural selection normally takes a brutal stance on a loss of fertility. For the vast majority of species, the message is simple: stop reproducing and you die. Just five known species buck this trend – humans and four species of toothed whale.

Grandmothers, it transpires, are the key to our shared post-reproductive anomaly. Killer whales are souped-up members of the dolphin family, with the smarts to match. These highly intelligent, highly social cetaceans live in family units of five to 20 individuals. Originally it was assumed these pods were led by the biggest male, with the smaller females forming his harem. We now understand that the leaders are not just female; they are the post-menopausal grannies.

These wise old matriarchs are living libraries for the environmental cultural knowledge that keeps their clan alive. By ceasing to reproduce halfway through their lives, they avoid competing with their daughters for the extra resources needed for pregnancy and lactation and have healthier grand-offspring as a result.

The same is true of humans. Research into hunter-gatherer societies suggests that such ‘grandmother effects’ also shaped the evolution of menopause in humans.

For centuries, female animals have been marginalised and misunderstood by the scientific patriarchy. Darwin is largely to blame. His theory of sexual selection branded females in the shape of a Victorian housewife: passive, coy, submissive creatures, whose only role was mothering.

Thanks to the rise of women scientists in the last few decades, a revolution has been brewing. It has redefined the female of the species and given her a modern makeover.

Take monogamy. It was long assumed that males are wired for promiscuity, whereas females will be choosy and chaste. But when feminist biologists started doing DNA tests on clutches of songbird eggs in the late 1980s, they discovered that each nest frequently had several fathers.

This rocked the world of ornithology and revealed a significant difference between social and sexual monogamy.

Some 85 per cent of songbirds do social monogamy very well and diligently pair up to share the parenting load. But females routinely sneak off to solicit sex with the neighbours to give her offspring the best chance of winning the genetic lottery. True sexual monogamy exists in less than seven per cent of songbird species, however devoted they may seem.

This revelation sparked a ‘polyandry revolution’. We now understand that multiple-mating is the preferred sexual strategy for males and females of most species, from lizards to lions to lobsters. Humans included, whose tendency for social monogamy is perhaps an artefact of our culture rather than biology.

What’s more, many female animals enjoy their licentious lifestyles. All female mammals have a clitoris. For some, like the domestic ewe, it’s a rather discreet affair, while for others, like the spotted hyena, it’s a flamboyant eight-inch organ that bulges forth like a penis. A 2022 study on bottlenose dolphins’ sexual anatomy pronounced the highly sexed cetacean’s clitoral morphology sufficiently similar to humans’ that intense sexual pleasure seems a likely reward for promiscuous behaviour. Like humans, dolphins regularly engage in sex that’s not aimed at conception – it’s just for fun.

Such hedonism is thought to help maintain social bonds in their complex society. Wild bottlenose dolphins have been observed partaking in group orgies, where males and females use snouts, flukes and flippers to excite the protruding clitorises of their cohorts. Direct stimulation has also been observed in sexual interactions between only females, which may dampen aggression between otherwise competitive individuals.

Across the animal kingdom, female competition generally revolves around access to resources related to reproduction – food, shelter or the fittest male.

Female topi antelope use their impressive horns to fight one another for the top bull’s limited sperm supplies. Some pushy cows even charge those females actively engaged in intercourse with the desired male – behaviour you might expect to see on an episode of Geordie Shore, not in the Serengeti.

When it comes to social species like primates, status is key for determining access to the best assets. Females generally inhabit some kind of formal hierarchy. Rank often passes down the maternal line and is therefore more predictable, and less dramatic, than male tussles for dominance.

But no less devastating. In savanna baboons, high-status females have it all: first dibs at food sources and a highranking protection racket for them and their babies. Low-status mums and their offspring are subject to bullying by those above. The resulting stress impacts their reproductive capacity and increases their chances of post-partum depression.

A low-ranking female baboon’s best chance of survival is to play a deft political game and ascend the social ladder through strategic coalitions with other females or males that protect her and her offspring.

Such diplomatic manoeuvring requires significant cognitive power. It’s probably one of the driving forces behind the increase in intelligence in all social primates – including us.

Lucy Cooke’s Bitch: A Revolutionary Guide to Sex, Evolution and the Female Animal (Doubleday) is out now