National Geographic : 1961 Jul
three weeks. This practice poses the question: How do the birds survive at all? Careful inquiries gave us the fascinating answer: The Indians, like ourselves, prefer fresh eggs. When an egg is incubated, an air cell forms in its blunt end and grows larger as the embryo develops. So a well-incubated egg will float, but one just laid will not. The In dians give eggs the water test; those that float go back into the nest. Incredible as it seems, human hands touch many of the world's rar est flamingos before they even hatch. Hip-deep in Ice-cold Mud The most difficult part of the expedition still lay ahead-to get within observation and trapping distance of colonies far from shore. I knew of Roger Peterson's terrible struggle through the lake's abrasive salt and almost impassable mud. Lucho repeatedly said of that trek with Peterson: "It was the worst experience of my life." With Gerardo and Leopoldo dragging a collapsible boat full of equipment, including our cannons and net, Bates and I set out in early morning. We planned to place the can non net near some nests that the Indian egg hunters had spared at our request. None of us wore boots, lest mud suction lock us in our tracks or even wrest the boots off. The water was like ice on bare feet. It gradually became shallower and the mud deeper. Blundering into seemingly bottomless holes caused by subterranean springs, we stayed close together to assist each other. The gum my mud became knee-deep, in places even hip-deep (page 101). Layers of sharp salt crys tals cut our feet mercilessly, causing them to bleed. Progress became a series of short strug gles punctuated by long gasps for breath in the rarefied air. Even talking was an effort, but Gerardo felt compelled to announce: "Here Doctor [Peterson] crawl on knees." At last we sighted the nests, curious mud mounds in long rows on low islands. As we crawled nearer, I realized how tired I was: Dizziness plagued me, and each heartbeat blurred my vision. The colony consisted of several hundred gabbling flamingos, almost all James's. A few sat upon nest mounds to incubate eggs the Indians had spared. As we approached, they took to the air. The nests varied in size, like those of other flamingos, but averaged seven inches high and 19 inches across at the base. Those spared 103 Hooded against snow flurries, which veil the far shore of the lake, Gerardo Barria, a Chilean member of the author's party, retrieves a trapped flamingo. Tide blown in by the daily wind swirls at his feet. Even in midsummer, salty mud freezes at night along the edges of the lake.