Nature Noir by Jordan Smith (romantic books to read .TXT) 📗

It was the latter that the biologists at Eight Mile Curve were actually looking for that June day in 1998. Lyme disease hadn't even been identified in the United States until 1975, and no one had heard of Lyme in the Sierra Nevada foothills until the early nineties. Even then it seemed rare and obscure. By that decade, the state Department of Health Services and the Placer County Health Department had began collecting a species of tick that was the local representative of the group that carries the disease to humans and animals, and a fair number of them had tested positive for Lyme. This western black-legged tick, Ixodes pacificus, carries the Lyme bacterium—a microscopic corkscrew-shaped thing known as Borrellia burgdorferi—in its gut and saliva, and disgorges the bacteria into people and animals when it finishes sucking their blood. Under a powerful microscope the spirochete, as this class of corkscrew-shaped bacteria is known to scientists, looks not unlike that which causes syphilis, and indeed the late-stage neurological effects of the two diseases can be somewhat similar, once the bacteria are fully disseminated in your brain and nervous system. Syphilis, however, is far easier to cure. Lyme is very curable early in the infection but devilishly resistant to antibiotics once it's hidden in the deep reaches of your body.

But the ticks are really just intermediaries, carrying the disease to a new victim after acquiring it from an animal that acts as the bacteria's perennial host. As Lyme research began in California, the perennial host animal—epidemiologists call it the "disease reservoir"—was generally found to be either a dusky-footed woodrat, a kangaroo rat, or one of a couple of species of deer mice. Woodrats are common in the oak forests of the American River. They are far prettier than you might imagine when you hear the word "rat": soft and furry, with delicately colored feet. Their nests, some quite large, are piles of sticks, often stacked against a tree or a rock on sloping ground. These serve generations of rats and their smaller cohabitants, the deer mice.

But at Eight Mile Curve, what the biologists found surprised them. While the ticks they collected on the site tested positive, only one of the many rats and pinyon mice they trapped did. So what was the disease reservoir—the mystery animal that passed the infection to the ticks? At Eight Mile Curve the biologists were seeing a good many songbirds feeding on the ground, and studies elsewhere—Europe, Asia, and the eastern United States—had found Lyme disease in avian hosts. So they turned their attention to birds.

What they then found was published two years later in the Journal of Medical Entomology: On the Foresthill Divide, within the lands the Bureau of Reclamation had condemned to build the Auburn Dam, birds were discovered with ticks embedded in them. Many of the ticks carried Lyme disease. Of ninety-two blood samples taken from birds there—towhees, warblers, sparrows, flycatchers, thrushes, finches, jays, and a single hawk—over half tested positive for Lyme; in some species the number was 100 percent. Many of these birds were neotropicals that traveled as widely as flight attendants, appearing in wintering grounds as far away as Central and South America.

Disease on the wing was an idea to get used to in California. Less than three years after the study went to print, the slow wave of West Nile virus, which was by then making its way across the United States at the speed of bird and mosquito flight, reached Southern California. There the virus's arrival was announced, as it had been everywhere else during its cross-country journey, by crows—which, among the avian victims of West Nile, seem to suffer greater mortality, literally falling like sparse black rain from the sky. But even before that, on the spring mornings when those men in moon suits lumbered through the oak forests of the Foresthill Divide carrying containers of little animals, although the air was still full of the familiar, if unseasonable, damp scent of spring, it was a new world.

By 1998 it had been twelve years since I had arrived to work as a ranger on the American River, twenty-three since construction of the Auburn Dam had come to a halt. During an informal meeting with officials from the Bureau of Reclamation in the late nineties, one of our rangers was told, "The Bureau has never deauthorized a dam, and we're not about to start at Auburn." And so our lives in the dam site continued to be a long improvisation. Without a unifying plan for the place—other than its eventual flooding—our effect on it was an aggregate of our individual whims and interests, all expressed in the makeshift way of things that happen under the shadow of a limited budget and a limited future. More often than not the right hand didn't know what the left hand was doing, and although one of my coworkers had made arrangements for the biologists to get into our locked gate at Eight Mile Curve, I never heard about the study until much later. As early as April 1997 the Placer County Health Department was warning citizens in radio ads to be careful about Lyme disease. California State Parks' response to this was not to respond; no cautionary memo was issued to rangers or their seasonal assistants working in the areas where infected ticks had been found. And while biologists who spent only a few hours in our park had taken elaborate precautions against infection, we who were there every day continued to go around in shorts in the summer, our guns no protection against a threat too small to shoot.

Among environmentalists there is a popular fable: If you drop a frog into a shallow dish of boiling water, the frog will fight for its life to jump out; drop the same frog in cool water and then very slowly heat the water to boiling, and the frog will perish with no apparent distress until the