By Sanjayan

Having traveled a dozen times to East Africa in about as many years, I no longer expect the unexpected on my trips there. That's how I nearly missed the ghost bird — or a chance to view evolution in action, to be more precise. 

It was just a white speck, perched atop a whistle-thorn acacia bush. Maybe it's a tern, suggested our guide, or a cattle egret.

And then we — six staff, trustees and donors from The Nature Conservancy — almost forgot about the bird. It was our party's first morning on the Serengeti — the greatest wildlife show on earth was awakening before us, and we had little time to get hung up on the commonplace.

But the bird's identification nagged at us, and we kept a distant eye on it. Then it took flight. Instead of the languid, predictable beat of the stalking egret, this one looped, rolled and barreled through the sky — a predator designed for maneuverability.

The mystery had just deepened. We had to follow it.

Nature Doesn't Go in Just One Direction

Other safari vehicles sped past on their way to a lion kill or perhaps the cheetah family on the hill. 

Meanwhile, thousands of wildebeest streamed past us, suspicious at the vigil we were holding parked near a lonely tree, where this brilliant white bird the size of a jay was preening.

It was clearly something new — something not in the guidebooks, something never before seen. The shape was familiar. But the yellow beak and dark eyes meant that the bird was not an albino, but a rare morph of something else. Though a mutant, it had made it into adulthood and seemed healthy enough.

Amidst the endless dramas of life (and death) on the Serengeti, it took this aberration to remind us that what we were seeing all around us was evolution — not just fodder for our cameras. Each death is at heart a natural selection, and each new life a further attempt to adapt to the environment.

Variation is the key to evolution, after all. If our very distant, single-celled ancestors had all been identical, we would never have made it out of the first oozy primordial pool; life would have blinked on, and at the first sign of hardship or changing environment, blinked out.

Of course most mutations don’t do anything at all, and the rest are usually bad. Only a very few actually do something good — improving on the previous design, and thus spreading through the population.

And it’s a humbling reminder to conservationists that the work of nature is not always directional. We may think we can fine-tune our approach toward picking what to save — but our choices might not always be right.   

Make Room for the Odd and the Strange

"The best" and "the most": These are two phrases all major conservation organizations use to set their priorities

Conservation has to triage — we have limited resources, and the Earth faces unlimited threats. We believe that careful choice of "the best" habitat, "the most representative" examples, etc., allows us to preserve future options.

But while protecting "the best/the most" is a rational strategy, it's one we should apply with humility. Because it's entirely possible that the "crash zones" — the places where habitats come together, where species mingle and where variation and selection can run rampant — are the drivers of change and of adaptation to future conditions.

A classic example of such a crash zone is the Wallace Line — the rich zoogeographical boundary between Asia and Australasia where species from two separately evolved continents come together.

But other, less dramatic crash zones abound everywhere: in transition zones where forests meet grasslands, where grasslands meet deserts, where corals meet mangroves, etc.

The Conservancy tries through its planning process to include these transitions in its conservation plans…although there is a strong pull to simply protect “the core” habitat — the best of every type, unadulterated by other habitats. 

Conservation should of course protect "the best" if we can. But we should also make room for the odd, the strange, the maligned. It's their novelty that provides a range of variations wide enough — on an evolutionary scale — to withstand the challenges nature throws at us.   

Will This Variant Live On?

We watched the bird carefully for over an hour — and then its I.D. came to us, haltingly at first, but then with conviction.

It was a type of roller — probably a Eurasian Roller, usually one of the most colorful birds in the world, like a child's painting of a bird.

None of us including our excellent guides had ever seen a variant of the roller like this one, and none of us expect to see one ever again. But we could be wrong. It's just possible that the bird's shroud of white might give it an imperceptible but eventually decisive advantage over its multi-hued brethren. 

Then the new trait would spread, and white rollers would become frequent on the plains. But it’s also possible that its difference will be its undoing. Unable to mate, the bird's distinctive trait would disappear. 

Savior or ghost — only time will tell.

The opinions expressed in "Wild Life" are the author's. They should not be construed as the position of The Nature Conservancy.

Read Other "Wild Life" Columns:

• February 2008:
  Worth a Thousand Words
• January 2008:
  The Jaguar and the Tiger
• December 2007:
  I'm the Diversity
• November 2007:
  Should We Save the Last Intact Places?
• October 2007:
  The Encounter
• September 2007:
  Climate Change and the Arctic
• July 2007:
  Mr. President and his Monkeys
• June 2007:
  The Perpetual War for Nature
• May 2007:
  A Road Called Optimism
• April 2007:
  The AIDS Drain on Conservation
• March 2007:
  Blood and Diamonds
• February 2007:
  To Shoot a Lion

Nature picture credits (left to right): Photos © Sanjayan (Eurasian Roller); © Erika Nortemann/TNC (Sanjayan); © Warwick Tarboton/VIREO (Eurasian Roller).