The other evening, I went to the window to look out on my garden but instead found myself face-to-beak with a dove. Its ramshackle nest was perched just below the windowsill atop a tree that has grown against the house. We looked at each other unblinkingly, its eyes framed by an electric blue that would make women of the '80s mighty jealous. I could barely contain my maternal excitement: Baby birds were on the way. I began Googling: "Nesting dove," "dove nests," "dove reproduction."
Wikipedia informed me, "The Mourning Dove is monogamous and forms strong pair bonds." When I went into the yard, I discovered another dove eyeing me suspiciously from the roof of a neighboring building as if keeping watch on the occupied nest. What teamwork! I did as any proper member of my generation would do when confronted by an awe-inspiring aspect of the natural world: I took out my iPhone and logged onto Twitter. "Just found there's a pair of doves nesting in my yard!" I tweeted. "Google says doves are monogamous and take turns with the babies/nest-building. If they can figure it out ... "
Moments later, I got a response from Debby Herbenick, a sexual health educator at the Kinsey Institute: "Yes, though DNA testing has found that many birds are socially, but not as sexually, monogamous as they seem .... :)," she wrote. A sad trombone riff played in my head: Wah-wah-wah. On an unthinking, emotional level I had taken doves' "monogamy" as an auspicious sign at a time when infidelity appears so common (it's something I've been thinking and writing about a lot lately). But, alas, even seemingly devoted doves were getting some on the side! She elaborated: "Many birds live as 'couples' ... but secretly mate with others. Fascinating stuff." Fascinating indeed, but I -- irrationally, I admit -- found it depressing.
I'm hardly alone in turning to the animal kingdom for insight on our own sexual behavior and what is or is not "normal." "Family-values" groups hilariously cheered the monogamy and parental dedication shown in the hit documentary "March of the Penguins," as though these flippered creatures served as a superior model for homo sapiens (never mind that, like doves, penguins are not as sexually "faithful" as they at first seem). Anti-gay conservatives like to use the abundance of opposite sex mating as an argument for why homosexuality is "unnatural"; liberal activists, on the other hand, point to same-sex pairings found in the wild to prove just the opposite. The prevalence of promiscuity in the natural world is used to explain the preponderance of high-profile sex scandals or, conversely, to make the point that the purpose of modern human society is to help us evolve beyond those baser drives. The truth is that there isn't any one "natural" way: "Animal species are incredibly varied in their sexual and mating behaviors," Herbenick told me. "There is no one standard."
I emailed Faye Flam, author of "The Score: How the Quest for Sex Has Shaped the Modern Man," a book that explores sexual evolution across species, for some further insight. "Studying other animals shows how complex and interesting mating behavior can be, and that there are many choices on nature's menu." There are animals that mate for life and co-parent, while other species practice a degree of promiscuity you would only find in the human world on the set of "The World's Biggest Gangbang." Oftentimes, when researchers call animals monogamous, they mean that "the pairs stay together just long enough to launch their young into the world, but in popular discourse, this would be 'serial monogamy' at best," Flam explains.
This sexual diversity exists not only "between species but also within species," Herbenick told me by email. That's also true of humans, of course. We have a rainbow's array of sexual orientations, fantasies and practices. Few people manage lifetime monogamy -- as in having one sexual partner for one's entire life -- but serial monogamy is "very common," she says. "Open relationships and outright cheating are less common but still prevalent." There is also tremendous personal variety: "Sometimes the same individual can be a complete slut in one phase of life, and a devoted spouse in another. It's also very hard to detangle our biology from our culture, since both are powerful influences on our behavior."
There is of course merit in looking to the animal kingdom for insight on sexual evolution, but extrapolating conclusions about ourselves is highly problematic. "It might be tempting to think that we're naturally as promiscuous as chimpanzees, since they are our closest animal relative," says Flam. "But observations of very closely related species of voles show that totally different sexual behavior can evolve very fast and can be under the control of just a couple of key hormones." It's also the case that "people do 'unnatural' things all the time, such as learning to play the violin, speak a new language, ride a bicycle," as David Barash, co-author of "The Myth of Monogamy," told me. "When something is 'unnatural,' it means that it is likely to be difficult, not impossible, and perhaps quite desirable!"
More than anything, our furry, feathered and scaled friends reveal where humans as a species fall on a broad spectrum of sexual behavior. "Monogamous animals, for example, tend to show very little size differences between males and females, and often, as in penguins and certain monogamous monkeys, the two sexes look almost identical," says Flam. "That's not us, but we're also not as grossly different as peacocks or gorillas." But, again, the variation within a species can be extreme. That's why "those who want to prove a point may find animals to back them up," says Flam, "but there are dozens of others that would likely do the exact opposite."
Nature is in bloom everywhere I look: In addition to the doves, there is a nest of pigeons in the alleyway alongside my house. There's also been an explosion of microscopic snails in my aquarium and, until recently, there were mysterious squeaks of baby birds coming from inside my living room wall. All this blatant reproduction is somewhat humbling; humans are just animals, after all. That isn't cause to look to critters' mating habits for an essential truth about humankind, but rather inspiration to marvel at the outrageous diversity of sex-driven evolution. Take the hermaphrodite snail in my aquarium that produced an enormous brood of babies all by its lonesome. Far from depressing, these things makes sex seem all the more spectacular.