Too Rich, Too Thin Study Of Baboon High Society Shows Drawbacks For Female Leaders

She had been poor and she had been rich, and everybody believed the vaudeville star Sophie Tucker when she assured them rich was better. Wealth, fame, success, status: these are the glorious bonbons of life, out of reach to most, perhaps, but desirable to nearly all. Who can doubt the plentiful benefits that come with being at the top? Who but … a baboon?

A long-term study of female olive baboons living in Gombe National Park, Tanzania, has revealed that while the high-ranking individuals in a group do indeed reap many nutritional and reproductive rewards from their status, they also pay a few unexpected costs.

The baboons that are the cream of their highly hierarchical and female-centered society - the grandes dames and their prima donna daughters - are able to monopolize the best foraging sites and to displace subordinates that happen first on a tasty patch of grass nodules or palm nuts.

As a result of their greater access to food, the alpha females reach maturity faster, their infants are likelier to survive, their daughters tend to become alpha females themselves and they can start reproducing again more quickly after each birth, compared with their beta through omega counterparts.

However, the dominant females turn out to have a much higher rate of miscarriage than do their subordinates, and in some cases they are not able to breed at all, a rarity among female mammals.

The new study suggesting that there is a price for being boss baboon, and that price is the most dreaded tithe of all, reduced fertility, was reported in the current issue of the journal Nature.

Dr. Craig Packer of the University of Minnesota in Minneapolis, who analyzed data that he gathered at Gombe with the renowned naturalist Jane Goodall and her co-workers, proposes that the fertility problems the dominant females experience are linked to aggressiveness: the higher the female’s status, the more aggressive she is likely to be, and possibly the more she may be loaded up with androgens, the male hormones. Those excess androgens could in turn contribute to fertility problems.

The researchers suggest that such a reduction in fertility could explain why females do not evolve in a steadily more aggressive direction, the better to accrue resources, trounce competing females and even fend off males that would tyrannize them.

“The idea we wanted to test is that perhaps it’s possible to be too rich or too thin,” said Packer, turning around the line attributed to the Duchess of Windsor. “We found that there is a cost to high status.”

The study is among the largest and longest efforts to quantify the lifetime reproductive performance, the socalled fitness, of animals situated up and down the hierarchy of their social milieu.

It takes to task easy assumptions that the leaders in a given setting are destined for genetic ascendancy and immortality. The researchers used data from 25 years of observations, taking into account the maternal careers of 138 female baboons with 584 pregnancies among them.

Although Goodall is better known for her work with chimpanzees, she has also been a dedicated baboon watcher, and this monkey was chosen for the analysis because it is shorter-lived than the chimpanzee and thus its complete story is more easily captured.

Other animal behaviorists praised the work for its breadth and precision, but some emphasized that when considered in sum, the data still supported traditional notions that high status has its perks in heightened fecundity. Dr. Jeanne Altmann of the University of Chicago, who has also studied baboons for many years, said that the inclusion of a couple of infertile baboons in the analysis skewed the outcome.

Nevertheless, the baboon study demonstrates strongly that dominance has its sword of Damocles side.

Packer said that even if one ignored the completely infertile baboons, the high-status females still ended up with twice the miscarriage rate of those lower in the pecking order, regardless of the age of the females under consideration.

The high rankers do manage to recover from their setbacks quickly, aided by their comparatively greater intake of food, but their susceptibility to spontaneous abortions indicates there could be an upper limit to having the upper hand.

In addition, while most of the high-ranking females had their first menstruation at a comparatively early age, as a result of their nutritious diet, a number were unusually delayed in menarche, not for want of food, but possibly because of hormonal imbalances.

The natural reining-in of the ruling class is probably the saving grace of baboon society, which is not exactly a model of pastoral civility.

Males come and go, and compete viciously among themselves for access to the stable of females. While the males tussle among themselves, the females maintain a rigid and reasonably stable hierarchy. An alpha male of today may be a washout tomorrow, but an alpha female is likely to die a star.

The general acceptance of the status quo does not mean the females are jolly and cooperative. They squabble, screech, chase and snap at each other, said Packer. Often, if a dominant female displaces a subordinate from a good feeding spot, she follows up with an act of overt aggression, such as biting the inferior on the base of the tail.

Whether the new study has relevance to humans remains one of those issues that is impossible to resolve - and impossible to resist speculating on.

Dr. Martha K. McClintock, a professor and chairwoman of biopsychology at the University of Chicago, who has studied the relationship between hormones and reproductive behavior in many mammals, warns against glib analogies between a dominant female baboon and a dominant female human.

“Are we to compare a dominant baboon to a woman who is working as a trial lawyer or an executive?” she said. “Or would a more apt analogy be with a matriarch in a large, extended family - an Italian or a Chinese grandmother, say?” Or Ivana Trump or Leona Helmsley, for that matter.

Nor is it clear that the most successful women are the most aggressive ones, she said. And while extreme stress has been shown to impede fertility, the causes of stress are many. Sometimes the most stressful thing one can do in life is nothing at all.