We arrive at our destination, and our group marches off into a swampy wilderness. It begins to pour, and then, for the next several hours, we all become drenched in rain, covered in mud.  Even Simon, in his khakis, is a mess.

Susan, Sandra, Simon and José each have an incredible ability to see and to find life.  The rain-drenched wilderness could appear almost lifeless. But when I realize that Simon has an extraordinary ability to see tiny animals hundreds of feet away, and that Sandra can pick out a tiny dot in the air and say, I think that's a zone-tailed hawk, I suddenly realize that the birder's hobby is directly related to the oldest joys of the wanderer.

Birders develop skills of wildlife observation because humans evolved to do exactly that.  And like those fishermen, who learn the subtleties of river currents, or the gardener who takes account of hundreds of species and packs her mind with botanical observations, the birder is taking part in a joy that is built into our species.

When anthropologists describe humanity’s earliest developments, they refer to us as generalists.  The features that make us uniquely human – our brains, our lack of body fur, our eyesight, our fingers – are the features of a species that foraged, collected, scavenged and hunted a wide array of foods seasonally from savannah to coast. In our earliest days, we learned to distinguish between hundreds of plant species, the types of seashore creatures and fish in the sea.  The parents of our distant ancestors trained their children to identify species at an early age – it was required for their survival.