Most desert animals do not require water daily. The deer, the bighorn sheep, the javelina are believed to go two or three days at a time without a drink, getting by, that is, on what they’ve stored in their tissues. Early March, also, is not the best of times for finding wildlife at a water hole; cool days, natural tanks full of winter rains, fresh plant growth make needs less pressing. Midsummer—July, August, September—that’s the best time. It was quite possible, therefore, that I would see nothing.

I waited. The air grew chillier, the moon slipped lower, the night came on. One more hour, I resolved, and then I give up; then it’s back up the trail by moonlight and down the other side, back to the truck, a beer, something hot to eat, before laying out my bedroll on the desert floor.

I heard the clash of stone far down in the brush-filled ravine below the spring. I raised the field glasses and studied the area but could see nothing in motion. I waited, changing position again to ease my aching limbs. Again I heard the slight, faint, far-off click of something hard on stone. An animal was approaching, and as I watched, concentrating on the mesquite and acacia thickets, I saw first one then a second sleek, gracile, dun-colored form appear, climbing on delicate hoofs up the path toward the spring. Followed by a third, a fourth, a fifth, all in single file. And then two more. And still more, at least a dozen in all, quiet as shadows, pale and obscure as the twilight, bodies barely distinguishable from the dark background of stone and brush.

For a moment I thought they were small deer. But all young bucks! With black spikes. And then I recognized them as desert pronghorn, a species almost extinct in the United States, though once quite numerous in southern Arizona. These had probably come up from Mexico, sliding under the fence like illegal immigrants. I was glad to see them. They gathered about the spring, jostling one another until the basic order of precedence was reestablished, then drank, two or three at a time while the others waited and watched. I could hear the gurgling of water passing rapidly down those parched throats, the sighs and grunts of satisfaction. There is something in the feeding and drinking of large animals that gives, to the human onlooker, a sensation of deep pleasure. Mammalian empathy, perhaps.

Finally the pronghorns had enough. A long time, as it seemed to me, for of course I had to wait until the last had drunk its fill before I could stir; I didn’t want to scare away from a much needed watering the lowest pronghorn in the pecking order. Not until all turned and started back the way they’d come did I stand up. At once, with a clatter of stones and armored feet, they took off. A dozen white rump patches flashed in the moonlight, vanishing two seconds later into the gloom below—soon gone beyond earshot as well as sight. I walked down and inspected the spring. A ring of dampness showed that the pronghorns had lowered the water level eight inches. I felt the muddy residue, then cupped my hands under the trickle that flowed from the algae-covered rock and drank.