WE CALLED IT the desert island game. Arriving at a train station or airport gate, you’d survey your fellow passengers—those with whom you were throwing in your body to hurl through space—and you’d have to choose by the time you boarded. Who would you want to be stuck with if it all went wrong?
We were teenagers. What did we know about other people? I’d have been horrified knowing I was auditioning for a part in someone else’s mental landscape while rummaging for pretzels or filling my water bottle. We were only just growing into an awareness of our mortality. We were role-playing as bodies on a planet we could not control. Trying to figure out when—if—love could stint our fear.
WHEN YOU THINK of global warming and birds, you might think of dehydrated birds falling from the sky, baby birds jumping from hot nests, or birds migrating at the wrong times. But as we face forecasts of wingless skies, it’s worth remembering that population health can be affected in quieter ways—when, say, courtship goes awry. Most creatures have a short window for breeding and conception, and though some birds mate for life, many face particular time pressure. A bird, unlike a human, cannot spend months observing a potential partner.
Near the beginning of the hottest month in history, I sat at my desk in Portland, Oregon, and watched a video of a male bird stand tall, puff his neck like a cobra, and launch himself into the air with a chirpy snort. He was a little bustard in his native habitat on the steppe of the Iberian Peninsula, where temperatures were lately climbing toward 110 degrees Fahrenheit. I was watching the bird’s mating dance, which happens at a lek, where males gather to show off for female birds. A recent study found that, as temperatures rise, the increasing need for birds to rest and preserve energy comes at the expense of this kind of exertion. When it gets too hot, they are less able to dance. Female bustards are then more likely to select different mates, because a weak mating ritual connotes greater overall weakness, potentially leading to less fertilization success and overall weaker offspring. Agriculture has already led to massive habitat loss. Even without heat waves, their numbers are declining.
In a Darwinian sense, “natural selection” describes how the most adaptive traits in a species will persist while others die out. For most species, the “why” behind partnership is to find a mate who can bear them the strongest and most successful offspring, and, in some cases, help provide for their nest. It’s less straight-forward to those of us for whom partnership means more than two figures of opposing sex. I grew up understanding I could marry whomever I want, but I now understand I have freedom over the of it too: not only do I not have to marry, I also do not have to marriage in any prescribed format. Just
