Twenty-one years ago Bernd Heinrich, a cold-hardened University of Vermont biology professor, burst upon the literary scene with Ravens in Winter, which did for corvids what Farley Mowat’s Never Cry Wolf did for canids. Although Heinrich’s later books ranged further afield--Bumblebee Economics explored the energy economy of bees, while Why We Run looked at what drives the oldest human sport--he’s never lost his fascination with birds.
In his new book, The Nesting Season: Cuckoos, Cuckolds, and the Invention of Monogamy (Harvard University Press, $30), Heinrich returns to his first love, and throws himself into an in-depth study of the mating lives of birds. The result is a fascinating exploration of the biological origins of bonding and emotional attachment. Birds choose monogamy mostly because it’s a great survival strategy. Sometimes it’s as simple as chore division: I sit on the egg, you go get supper. Other birds, like those in the cuckoo family, use tag-team diversion and stealth to insert an egg into the nest of another species, where it’s raised as a foster chick--hence the word "cuckold." Cuckoos, in fact, come off like the grifting swingers of the bird world. Whereas most avian luuv-making is, as Heinrich notes, "a perfunctory affair lasting about two seconds," cuckoos go at it for a good two minutes. Roadrunners (a species of cuckoo) "copulate at the site where they will build their nest, and they continue to do so even after their clutch has been completed," Heinrich writes, "hence suggesting their activities function to bond the pair."
The big question: Do birds feel love? The answer: Heinrich wouldn’t call it love, exactly (hey, he’s a scientist). But he does turn up evidence of emotional attachment, grief, joy, deception, and play--always driven by the imperative to survive and reproduce. Which sounds a lot like human love.