Birds in flight possess flawless instinct. I don’t believe that – after thirty years of daily soaring activity and twice as many on the ground looking up, I know it. Not to say birds are incapable of error, but next time one does something that appears graceless or counterproductive, keep watching. Was that a fledgling’s ungainly first attempt at what will be its specialty for as long as that specialty keeps it alive? (Even agile Bambi must have stumbled a time or two her first day… ) Or might it be an individual bird of any age or species indulging in idle playfulness? You’ll see that a lot, too. Go to a park and feed the birds until they don’t want any more, then sit back and watch. Once they’re finally bored, some get grumpy and quarrel about territory, but the smart ones continue to display the curiosity that got them there.
Whatever the circumstance, the genius of instinct is always a central theme in the behavior of birds. There are too many stories to even remember, so let’s settle for just the latest.
Watching two turkey vultures glide slowly by into a robust wind, I noticed a subtlety I’d never recognized before. The birds’ staggered formation was loose by airman standards, but the longer I watched the more it seemed ideal for their purpose – they are birds, after all. The one flying lead was visibly bigger (older and more experienced?) than its ‘wingman’ who held position at eight o’clock a couple hundred feet back. (Mother and son perhaps?) That second bird, the ‘wing’, exhibited what seemed an unlikely error, but readiness to learn fast as well.
These guys know how to fly S L O W. Their specialty, if you want to call it that, is a glorious, airborne version of laziness. Vultures commonly glide less than a hundred feet up, Inching along at a walking pace and oddly rocking their wings every few moments… Each rock is a stall recovery! Yet no one would attribute that to lousy flying skills. It’s simply the easiest way to fly really, really slow in very weak lift. They mean to do it; it’s not an error. You’ll seldom catch one of nature’s supreme soaring creatures stalling by accident in any situation, especially for example at the top of an ordinary pull-up in lift… But that is what I saw last night.
Their ground speed looked close to zero while pulling up in periodic lift, and maybe triple that when they dove through sink. First surprise, on several pull-ups the wing got too slow and actually did stall. Recovery was instantaneous of course, but that cost energy… The wing was supposed to be keeping up with the lead, who already held advantages in gross weight and wing loading, and flying too slow and recovering from stalls didn’t help.
As the lead bore on STRAIGHT into that headwind scarcely moving a feather, its ups and downs gave evidence of lift and sink well before the wing entered that same air. The genius is in what the wing did with this information.
Each time the lead entered lift the wing would edge toward it and wait to reach the lift before pulling up. Once that lift was behind them the wing would slide back to its previous separation. Then when the lead hit sink the wing would immediately veer away, again waiting to reach the sink itself before nosing over. In this way, a bird whose overall flight control was demonstrably less efficient was able to share in the other’s lift while avoiding at least some of its sink. Despite having to fly a longer flight path the wing managed to keep pace, never once flapping its wings. All the while, those two geniuses together were expending less energy than you do simply holding your head up to read these words. (Also, by the time they flew out of sight the wing was no longer stalling at the top of those pull-ups!)
Now don’t we just have to call that genius? Don’t tell anybody, though. If people flew like that without being tongue lashed, and improved so quickly on their own, I’d be out of work!