But unlike the birds themselves, penguin sexuality is not all black and white. That perfect penguin pair, that “ideal example of monogamy,” those “model parents” are monogamous only as long as it takes to get their little one out of the egg, off the ice, and into the frigid Antarctic water—a little less than a year. If you’ve seen the film, you know that with all the trekking back and forth across the windswept ice and huddling against raging Antarctic blizzards, there’s not much in the way of extramarital temptation anyway. Once Junior is swimming with the other eleven-month-olds—the penguin equivalent of kindergarten—fidelity is quickly forgotten, divorce is quick, automatic, and painless, and Mom and Dad are back on the penguin prowl. With a breeding adult typically living thirty years or more, these “model parents” have at least two dozen “families” in a lifetime. Did someone say “ideal example of monogamy”?
Whether you found the film to be cloyingly sweet or refreshingly so, a bold, if somewhat perverse, double feature would pair
The prairie vole is another supposed paragon of “natural monogamy”According to one newspaper article, “Prairie voles—squat rodents indigenous to plains and grasslands—are considered to be a near-perfect monogamous species. They form pair bonds that share a nest. Both male and female actively protect each other, their territory, and their young. The male is an active parent and, if one of the pair dies, the survivor does not take a new mate.”19 Considering the vitriol Darwin faced 150 years ago when he dared compare humans to apes, it’s striking to note the scraps of comfort contemporary scientists find in equating human sexual behavior with that of the ratlike prairie vole. We who once compared ourselves to angels now see ourselves reflected in this lowly rodent. But C. Sue Carter and Lowell L. Getz, who have studied the biology of monogamy in prairie voles and other species for thirty-five years, are unambiguous: “Sexual exclusivity,” they write “is not a feature of [the vole’s] monogamy.”20 Thomas Insel, director of the National Institute of Mental Health (formerly director of Yerkes Primate Center) and an expert on the prairie vole, says that those in the know have a less exalted view of the prairie vole’s monogamy: “The21 ll sleep with anyone but they’ll only sit by their partners.” 1
Then there’s that line (invariably directed at women, for some reason) that goes, “If you’re looking for monogamy, marry a
*
swan.”
So what about swans, then? Many species of birds have long been believed to be monogamous because two parents are needed for the 24/7 labor of incubating eggs and feeding nestlings. As with humans, investment-minded theorists assumed males would help out only if they were certain the young were their own. But the recent advent of affordable DNA testing has blown embarrassing holes in this story, too. Although a pair of bluebirds may build a nest and rear the young together, an average of 15 to 20 percent of the chicks are not sired by the male in the partnership, according to
Patricia Adair Gowaty, a behavioral ecologist. And bluebirds aren’t particularly slutty songbirds: DNA studies of the chicks of some 180 bird species previously thought to be monogamous have shown that about 90 percent of them aren’t. Swans, alas, are not among the virtuous 10 percent. So if you’re looking for monogamy, forget the swan, too!
HELEN FISHER
Strange trademark for a species that enjoys so much
