So how to teach young cranes where to go at migration time? When humans raise cranes, the cranes tend to bond to the people raising them -- which meant that the cranes are not the least bit interested in flying anywhere without their humans. They need to bond to something that ... flies. Something that could lead them in flying long distances. So William Lishman, a pilot of ultralight aircraft, came up with "Operation Migration." The idea was to bond fledgling whooping cranes to -- yes -- an ultralight aircraft. So from the time the cranes can struggle up onto those ungainly legs, they are fed and cared for by humans garbed entirely in white with crane-head puppets on their arms. Soon the white-garbed humans are whirring around them in machines that look and sound like ultralight aircraft. Then eventually the ultralight plane itself is brought in, leading them on short flights. The cranes grow up thinking this noisy little machine is their parent -- perhaps the evolutionary trade-off for having beautiful big wings and a small aerodynamic head.

And when it is time to migrate, to take that transcontinental trip to some winter place? The ultralight takes off, a flight of faith -- and the young cranes follow it into the air. They know they are supposed to go; they just don't know where. So off they fly with this human dressed like a Ku Kluxer in a silly little flying machine out of a Mad Max fantasy.

And I challenge anyone to watch this, or a video of this, without experiencing a need to surreptitiously wipe at your eyes. It is beautiful. It is also crazy. Absolutely crazy beautiful. Absolutely cranish.

I was almost embarrassed, leaving a viewing of the video of this, to find questions squirming into my mind. If we can devote this kind of altruistic and creative intelligence and money -- this isn't cheap -- to pea-brained birds with the wings of angels, why are we so helpless, so unimaginative, so unmoved, in the face of human poverty and destruction, the sufferings of our own kind? Why can't we or don't we apply that kind of creative intelligence to health care? Infrastructure? Education? Intercommunity, interracial, international conflict?

I have no answer for those questions. I can only throw out hypotheses like ropes with grappling hooks, hoping they catch on something. Perhaps  we as a species are all -- as Dylan Thomas put it -- "as mad as birds." Are birds mad -- cranes crazy? It's probably more accurate to say that cranes are just cranish. That once the cranes learn where to go, it's not crazy for them to fly there and back again every year, even if it means crossing whole continents. So by extension, for a member of Homo sapiens sapiens, understanding the craziness of lavishing love on birds while our own kind go wanting -- well, I'm losing the thread here, my end of the rope, in a cranish way: I can think, I want to think it through, but I don't know where to go with it.

There's something I keep thinking about when I ponder the way we seem to be, as the planet gets more crowded with us and our consequences -- a changing climate, the imminent terminal fever of petroleum supplies we don't know how to do without, out-of-control mad spending on foreign wars even as we slash public spending on our own well-being just when we most need the help, our inability to escape from a perpetual state of war against everything from terrorists to drugs to collateral citizenry -- all these things, none of which we seem to have the will to address. I keep thinking about what I said back at the beginning of this essay: I think about evolution. What will we be when we grow up? When or how do we learn where we're supposed to go?

Biologists have shown that there are species that never do actually grow up -- that is, they have no adult stage. These species live in environments so harsh that most of them never reach an adult stage of development; they only survive if they are able to breed in their immature forms. There's a subspecies of salamander found in some ponds in the high mountains near where I live that remains in its immature aquatic state all its life. It never trades its gills for lungs to go amphibious, to leave the water -- and it breeds that way. It is what biologists call a "neotenous" species: After a long enough time of breeding in immature stages, retaining its gills, it loses the capacity to lose its gills and become an adult able to live in two environments rather than one.

Now some biologists are suggesting (not very loudly) that we humans might be a neotenous species -- "the neotenous primate," as one of them puts it. Hundreds of thousands of years in the hot and cold deserts of the Ice Age were so hard on our species that we only survived through the breeding of adolescents -- basically, teen pregnancies. Most paleontologists agree that surviving to the age of 20 only a few hundred thousand years ago was like living to 60 or 70 today. A Hobbesian "poor, nasty, brutish, and short" life meant that few humans actually reached physical or psychological adulthood -- and over those tough millions of years, the scientists say, we may have lost whatever the characteristics would have been for Homo adultus.

I won't go into all the evidence that persuades some scientists that this is the case. But it includes physical conditions like our mostly hairless bodies and the relatively large head-to-body ratio that mature primates lose; and it includes psychological conditions like the persisting desire to learn (which other primates lose at an early age), and the lifelong need many of us have for a stern but loving "parent figure." You can extrapolate the political and religious implications there yourself.