A Heritage In Peril


Coming from an Old World intensively cut over, cultivated, and grazed by domestic animals, Europeans were awed and often overwhelmed by their first glimpses of North America—the clouds of sea birds enveloping rocky islands off Newfoundland, the waterfowl crowding sandy beaches and inland rivers, the stately forests with their “tribes” both feathered and furred that knew not the yoke of man.


Coming from an Old World intensively cut over, cultivated, and grazed by domestic animals, Europeans were awed and often overwhelmed by their first glimpses of North America—the clouds of sea birds enveloping rocky islands off Newfoundland, the waterfowl crowding sandy beaches and inland rivers, the stately forests with their “tribes” both feathered and furred that knew not the yoke of man.

The Vikings and such latter-day explorers as Verrazano, Cartier, and Champlain encountered the deciduous eastern forest, where trees towered in parklike splendor, twenty feet in girth and one hundred feet high, over a forest floor nearly clear of brush. Luxuriantly cloaked in grapevines from head to foot, these giants showered down acorns and other nuts, including the finest chestnuts ever tasted, and the meadows brimmed with wild oats, strawberries, and flowering peas. The sweetest songsters in these woods were not nightingales, as in Europe, but shy wood thrushes, hidden among the tangles.

During the seventeenth century, English visitors to Virginia found “goodly tall Cedars” and counted “14 severall sorts of sweete smelling tymber trees,” on whose seed crops depended large flocks of wild turkeys, parakeets, and passenger pigeons “so thicke that even they … shaddowed the skie” from the beholder.

When Henry Hudson dropped anchor in New York Harbor in 1609, he found Manhattan a “very good woodland” with grassy glades and “fresh water running through it, pleasant and proper for man and beast to drink.” Atlantic salmon and whales were to be found as far north as the future site of Albany, up the river that would bear Hudson’s name. In the clear tidal rivers of the coastal plain, fish and shellfish were in great store, and often grew to immense proportions. The seventeenth-century English writer John Josselyn attests in New Englands Rarities to oysters nine inches long, which had to be cut in three pieces before they could be swallowed, and sturgeon sixteen feet long.

No one could yet guess the extent of the eastern forest, covering a third of the continent and populated, according to Myers’ Early Narrative of Pennsylvania, West New Jersey and Delaware, by such mysterious creatures as the “Possam . . . having a false belly to swallow her Young ones” and “that Remarkable Creature the Flying Squirrel, having a kind of skinny wings, almost like those of a Ban.” The hills then harbored not only foxes and deer but wapiti, moose, wolves, cougars, bobcats, lynxes, and fishers. In the swampy lowlands, otters, muskrats, and beavers sported. The vistas of autumn, unbroken by cultivated fields, presented to Thomas Pownall, geographer and colonial governor of Massachusetts, “an Appearance beyond Conception.” Having known fewer and less spectacular deciduous trees in their native lands. European settlers were constantly amazed by the displays of color, especially the clear reds and deep scarlets of maples, rising hill oxer hill, as in an amphitheatre.

The southern fringes of this forest were very early glimpsed by Spanish conquistadors. Though they sought golden cities that they could not find, they were nonetheless impressed by the southern pines, “well proportioned and as tall as the tallest in Spain,” and the hammocks of tropical forest, rising like islands on the watery prairies of Florida, “very difficult to travel and wonderful to look upon.”

Marching north from Mexico in 1540, Coronado’s men discovered the Grand Canyon of the Colorado and endured the monotony of the Great Plains—the trampled sod, the herds of bison that they called “hunchbacked cows,” and the big sky all around. Some sixty million bison ranged from the Rockies eastward into the woods of Georgia and Pennsylvania; Coronado later told his king that “there was not a single day that I lost sight of them.”

As for the west coast, it was not reached by land until the Spanish decided to colonize California, and sent Gaspar de Portolá as its governor in 1767. North of San Francisco, Portolá came upon the redwoods and realized for the first time the grandeur of the tallest trees in the world, three hundred feel high and so massive that “eight men all holding hands could not span one of them.” Since seamen never sailed more than one hundred miles up the Columbia River, they also missed the wild beauty of the Cascades, unexplored until Lewis and Clark opened up the great spruce and fir forests of the Pacific Northwest in 1805.

At the time of these discoveries, North America was unexploited except by Indians, whose numbers never rose much above a million. Only where their towns were heavily clustered along the coasts, around the Great Lakes, and in the Southwest did the natives of the continent leave some lasting mark on the land.

Northeastern woodland Indians cleared large acreages for their use, and migrated every thirty or forty years to find new soil for crops and new wood for houses, canoes, weapons, utensils, and firewood. As hunters, they were generally more conservative than the white men who succeeded them. Some actually divided the territory controlled by the tribe into family hunting arounds, keeping an inventory of game and imposing limits on themselves. In the south, though less wood was needed for fire and shelter, the valley flats and hillsides were burned to flush out game, a practice that created savannas of brush and grass—excellent feeding grounds for deer, wapiti, bison, heath hen, and turkey.

On the plains, the nomadic hunters of the bison also burned off the old, dry turf, clearing the ground for new growth of protein-rich legumes and grasses. Prevailing west winds carried these fires, as well as those started by lightning, into what are now Iowa, Illinois, Indiana, and Ohio, carving out peninsulas along the border of the great eastern forest that also became grassland.

When the Indians were driven out, the tall grass prairies were gradually plowed and planted, and most of the burning ceased. So the hardwoods returned, wherever possible. The winged seeds of the cottonwood, the elm, and the silver maple took hold along the streams, and on the drier uplands shrubbery broke tip the thick sod, shaded out the grasses, and was eventually eclipsed by young oaks and hickories. Thus, at first, the landscape built up again, until it was covered with the vegetation most suited to the climate.

Such natural buildups and breakdowns (whether by fire, ice, or other disturbance) are continuous. But the kind of breakdown accomplished by European man has been much faster and more complete; and in some areas the damage wrought is irreparable.

Only three hundred years after the arrival of the first settlers, the face of the continent has been drastically altered. The forests have been cut down; cattle and sheep have overgrazed the rangeland; the plains have been planted and tilled, often unwisely; marshes have been drained and high dams built that have backed up the waters of rivers into valleys and canyons. Sewage and other wastes from growing cities and industry have polluted the waters.

Among the birds that have become extinct along the way are the great auk, the Labrador duck, the passenger pigeon, the heath hen, and the Carolina parakeet—all of which had been very plentiful and gregarious and were easily killed for food or sport. The snowy egret was nearly shot off its marshy breeding grounds for the sake of its nuptial plumes, a favorite decoration for ladies’ hats. Before 1890, ten million people had settled the West, the Great Plains were stocked with more than eleven million head of cattle, and the teeming millions of bison had been slaughtered almost to the last individual. The pronghorn antelopes, once as numerous as the bison, were down to about 30,000. mostly in the Southwest and Far West. About 125,000 wapiti survived in the northern forests and the valleys of the Rocky Mountains. The big carnivores also retreated into these relatively inaccessible places and into the wilds of Florida. Mountain sheep were driven higher in the Rockies, to the tundra homes of mountain goats, and the desert bighorns dropped to only 300.

As soon as timber became scarce and topsoil on the cutover lands had washed away, clogging river bottoms with silt and killing fishes, cries for conservation were heard.

At the turn of the twentieth century, watersheds were replanted and massive reforestation projects were begun in the South and West—tree farms for the raising and harvesting of fast-growing conifers. Areas strip-mined for coal were graded and replanted. Much later, in the prairie states, the soil bank was formed to let nature heal the wounds of drought, plowing, and overgrazing.

At mid-century, however, war and prosperity caused new inroads into natural resources, and today a population of 195 million, bigger cities, and bigger industry have made pollution of the air and water a bigger problem than ever. About eighty-five per cent of the contiguous United States is either farmed, grazed, or lumbered, often not wisely; farm and ranch lands equivalent to the combined areas of Texas and California have become man-made badlands, desolated by erosion. Giant old redwoods are still being felled as new crops grow to “commercial” size (which takes about eighty years), and in the west coast valleys of the Eel, Klamath, and Smith rivers the denuded hillsides pour down torrential floods.

True, man has the primary claim to the land. But in making use of the land he has too often destroyed its natural variety, coupled conservation of game with the killing of predators, and then broadcast poisons to cut down the resulting overpopulations of pests. Some of these compounds, applied directly or by plane over 89.5 million acres every year, are so stable that they circulate through food chains for years. Rachel Carson’s prophecy of a silent spring has come true in many communities where robins and insect-eating birds have sharply declined or disappeared; and massive fish kills on the lower Mississippi dramatize the threat to our own food supply, for man himself stands at the end of a food chain. “If man refuses to follow wise conservation practices in controlling his economic affairs, the ultimate victim may be not natural beauty or birds and fish but man himself,” said the New York Times recently, repeating a warning issued by Secretary of the Interior Stewart L. Udall. “Unless man, the giant predator, becomes the farsighted conservator of this planet, he may join the whooping crane, the great blue whale and the golden eagle as a threatened species.”

Prey and Predators: A Balance Upset

Far-sighted conservation policy must recognize a central fact: that the control of nature depends on a balance between prey and predators. Yet all too often in the white man’s tenure on this continent, such conservation as he has practiced has been in the nature of response to emergencies, with little regard for the long-run ecological balance.

A repeated victim of the resulting confusion has been the deer, one of America’s most beautiful wild creatures, a source of food for Indians and pioneers, and, in latter days, one of our prime game animals. In the eastern deciduous forest of 1600, the white-tailed deer population varied from about 100 to 840 per ten square miles. One or two wolves or cougars in the area kept the number of deer stable by killing off about a quarter of them each year. But as the land was settled and the wilderness shrank, these predators disappeared. The cougar, whose hunting range is twenty to sixty miles, and the wolf, whose range is ten to twenty, had no place to go except to cultivated areas, where they were shot as a menace to game and livestock. Bobcats, who prey on very young, sick, or old deer, could not take their place, nor could the omnivorous black hears, foxes, raccoons, skunks, and opossums.

So, as the nation flowed westward, deer increased on the abandoned eastern hill farms and in the lumbered-off forests. At the same time, they were protected by game laws: as early as 1677 Connecticut placed restrictions on killing them and exporting their skins; similar legislation followed dose on the retreating frontier, reaching California in 1850.

By 1880 on Mt. Desert Island in Maine, there were too many deer, and wholesale starvation occurred six years later, during winter ice storms. The Adirondacks experienced their first irruption in 1896, about a decade after the wolves and cougars were gone. In the West, the first recorded irruption of mule deer, on the Kaibab Plateau of Arizona occurred in 1924, fourteen years after government predator-control had exterminated hundreds of cougars and wolves. The herd grew from about 4,000 to 100,000 until meadows and coniferous forests were overbrowsed and mass starvation ensued. By 1938, the number of deer had dropped 10,000. The Kaibab then became a matter of national concern; the range was expanded and replanted, predators were allowed to come in from the surrounding territory, and limited hunting was restored. As a result, this national forest now supports a deer population of about 13,000.

The lesson of the Kaibab, however, came too late. Well into the mid-twentieth century one hundred trouble spots, varying in size from a small refuge to half a state, suffered deer irruptions; of these, nearly half reported a “crash” in numbers from starvation, and the rest alleviated their problem temporarily by allowing; open season on does. Only one-tenth claim to have restored a balanced community, however; all the rest are irreparably out of step. When the shrubs have grown up again, there will be more population peaks, followed by more crashes. When game managers warn of an impending irruption, state legislatures are fearful of increasing bag limits because of almost certain political censure later on, when it may become necessary to lower them again. Hunters, it seems, cannot even begin to control deer populations.

But most of us are not hunters, and the number of dedicated deer-watchers is limited. If the confusion in our efforts to control nature were limited to game laws, the apathy of the general public would perhaps be understandable. Unfortunately, it does not stop there: it extends to our use of our western ranges, to our agricultural methods, even to our tending of lawns and gardens. Our indiscriminate use of pesticides still threatens a silent spring which might fundamentally alter the kind of America in which most of us want to live.

Confusion on the Range

On our western ranges, game and livestock protection and rodent control are hopelessly confused. The basic problem is overgrazing. The Texas longhorns were little more than replacements for the bison, and the longest cattle drives were, in their effect on the land, not unlike the buffalo migrations: a longhorn herd, always on the move, allowed the range to recover before the next drive appeared.

Then came the barbed wire and the windmills that made homesteading and the raising of pedigreed beef cattle the new industries of the plains. The stock farmer sank wells, making water available on dry pasturage, and brought in the shorthorns and Herefords that would, unlike the longhorns, live docilely behind fences. Inevitably he ran too many cows on his fenced-in pastures. Each cow needed at least thirty acres of prime grassland. With several cows on that amount of pasture, and perhaps sheep and horses, too, the farmer could manage only by supplementing the natural range grasses with field crops of sorghum and maize. But in a drought, the crops failed, weeds grew up on the worn-out land, and jack rabbits and rodents proliferated. On the circumstantial evidence alone, it seemed to many a ruined stockman that these animals—not the drought or the overgrazing—were responsible for the sorry plight in which he found himself.

But they had not been in really serious competition with his cattle for the range grasses. If he had looked carefully the previous year, when the range was still in fairly good condition, he would have seen that jack rabbits were feeding near a water trough, where the cows had already worn away the grass and a patch of weeds stood. Rabbits and many rodents actually prefer weeds. Nor, once the bison had been all but exterminated, was any of the big game animals ever in competition with cattle for food. The pronghorn antelope may be observed eating considerable quantities of weeds along fence rows and in gullies and breaks. Mule deer concentrate on shrubbery among the rimrocks. White-tailed deer browse high in the mountains, wapiti along the borders of coniferous forests.

On the other hand, the damage done by the stockman’s animals does affect the wild game. Continued overgrazing has prevented the return of the natural grasses of the range, like buffalo grass and bluestem. On the Big Bend in Texas, for example, where once there were great grassflats, only brush now grows, and much of this arid area has reverted to desert scrub, mainly creosote bush or greasewoocl, which none of the game animals can eat; the spread of this poor habitat lessens their chances for survival.

Two plains animals, however, were in part responsible for the stock farmer’s losses: the prairie dog, which does eat a good deal of grass (preferring the fertile river bottoms most valuable to cattlemen), and the coyote, which not only feeds upon the man-made irruptions of rabbits and other rodents but also attacks sheep, cattle, and starving game.

To eradicate these troublemakers, and particularly to kill the hardier coyote, more and more deadly poisons have been devised. At first strychnine was used, but its taste made coyotes shy away from the poisoned bait. Thallium compounds, developed after World War I, were thought to be the answer. They were tasteless and acted slowly, assuring that a lethal dose would be absorbed. The trouble was that thallium also killed other wild and domestic animals that ate the bait.

By the late 1940’s another nerve poison, sodium fluoroacetate (“1080”), had been developed. Theoretically, it could be used selectively, to kill only the coyotes and rodents for which it was intended. But 1080 turned out to be many times more lethal than thallium; a pound of 1080 is enough to kill a million pounds of animal life. Worse, it is highly stable in rodent bodies, causing secondary poisoning of scavengers and predators. Not only the coyote but the golden eagle, the kit fox, the black-footed ferret, or the condor that dines on a ground squirrel killed by a particle of 1080 may also die. Thus, rare and desirable animals, as well as the so-callecl pests, have become the victims of an ill-considered policy.

Today the traditional rationale of predator and rodent control is being challenged. Scientists are beginning to wonder whether it is sensible to kill both the rodents and rabbits and their predators. Similarly, questions are being raised about whether the money spent on killing certain predators is justified by the returns. Considerable government funds are being spent, for example, to kill coyotes throughout California’s national forest lands, though only a small part of these areas is being used for sheep grazing.

And positive steps are being taken to broaden our understanding of the whole field of game and livestock protection. In research centers at Patuxent, Maryland, and Denver, Colorado, the United States Fish and Wildlife Service is experimenting with new solutions to predator—and rodent-control problems. Their trouble-shooting inventions range from sonic warning systems to ward off blackbirds to birth-control drugs for coyotes. In the Southwest, golden eagles, implanted with tiny transistor radios, are being tracked to determine how much—if any—damage they do to herds of sheep and goats. A federal law was enacted in 1962 to protect the eagles, after some 20,000 had been shot in twenty years of intensive campaigns. As might be expected, it is being appealed by ranchers.

In wilderness, of course, is sanctuary. Two years ago President Johnson signed an act that would preserve, in perpetuity, nine million acres of Wilderness Areas, accessible only on foot or on horseback. But powerful commercial interests block every new acquisition, and some private companies are already at work undermining the Wilderness Act. San Gorgonio Wilderness Area, near Los Angeles, is now being contested before a House subcommittee by would-be developers of a ski area. Southern California’s last forty condors, huge scavengers from the ice age with wings spanning nine and a half feet, are being made more secure at their Sisquoc Falls roost by its reclassification as the San Raphael Wilderness Area; but they face destruction in another part of the Los Padres National Forest. Builders of a proposed dam on Sespe Creek, just north of their nesting grounds, are planning to drive an access road from the town of Fillmore directly through the heart of the refuge. In March of this year the taxpayers of Ventura County rejected the $50 million project by a margin of only forty votes. Most of them were more concerned about the project’s effect upon their tax bill than upon the condors, however. And the promoters will be back.

The Contaminated Web of Life

The use of poisons to control pests has not been limited to the western ranges. A whole new group of chemicals has been developed for use against insects that prey on shade trees, on field cops, even on lawns and ornamental shrubs: because these are readily available and seemingly effective, we have used them in large quantities over large areas, without much regard for their ultimate effects.

Recently, however, we have begun to learn some alarming facts. In the first place, it has become apparent that most of these compounds can be only a treatment for insect irruptions, not a cure. They do not completely eradicate pests; on the contrary, the pests often build up a resistance to them. This phenomenon has been known for half a century, but it was not borne in upon the public consciousness until just after World War II, when it was generally noticed that houseflies and mosquitoes, after being sprayed with the initially effective DDT, came back in numbers greater than before, and this time DTT could not control them. To the present day 120 species of insects have managed to outlive the development of stronger and stronger pesticides.

Not only do pesticides damage nature’s own system of controls by killing less prolific insect enemies of the target pests along with the pests themselves; they kill other wildlife as well, either by direct application, through aerial drift of the chemical sprays, or through the runoff of residual poisons into watercourses.

Another insidious fact has been discovered: relatively small, “safe” amounts of poison are stored in animal bodies and passed along the natural food chains in larger and larger concentrations. Food-chain poisoning was first brought to public attention in 1958, when Dr. R. J. Marker published the results of his research into the deaths of robins and other birds on the campus of the University of Illinois. There elm trees had been repeatedly sprayed with DDT to combat Dutch elm disease, a fungus that had spread throughout some twenty states. Trees sprayed in the summer dropped contaminated leaves, causing a concentration of DDT in the soil and in the bodies of earthworms. By the time the robins returned in the spring, their favorite food was poisonous. A single worm harbored ten limes more DDT than the soil, and a diet of a hundred worms was enough to kill a robin. In sixty eastern and midwestern communities, robin populations dropped drastically, anywhere from thirty to ninety-eight percent. Nor were robins the only victims: approximately eighty species of birds were affected—orioles, warblers, and vireos of the treetops (which picked up the DDT from spray-drenched insects), flickers (which eat bark beetles), and falcons (which feed on flickers). It is suspected that a similar DDT concentration process may be responsible for the nesting failures of bald eagles on Lake Michigan, in Maine, and in the mid-Atlantic states; of the osprey north of Chesapeake Bay; and of the beautiful peregrine falcon, which has today virtually disappeared from the entire Northeast. Pilot investigations by the California Fish and Game Department in 1961 have shown that in rice fields treated with DDT, ring-necked pheasants laden with this and other pesticides are able to hatch eggs, but the survival rate of the young is very poor.

A decade was needed to prove that the widespread use of chemical sprays had a crippling effect on the reproductive systems of fish, too. In 1956 and 1957, every one of the young trout hatched at the Lake George Fish Hatchery in New York’s Adirondack Mountains died. The eggs had been collected from a watershed that had been plied with DDT for the control of gypsy moths, blackflies, and mosquitoes. Small fish were concentrating the chemical and passing it on to the female lake trout, which in turn were destroying their own progeny by passing it into the stored fatty material of their eggs.

On the lower Mississippi River, a delayed reaction to another pesticide, endrin, precipitated the deaths of three and a half million fish in 1960, a quarter of a million more in each of the two succeeding years, and a staggering 5,175,000 in the winter of 1963-64. For the first time, in every major waterway, more fish were being killed by pesticides than by all other causes combined—sewage, soaps and synthetic detergents, oil, tar, and the leakage of sulfuric acid from mines.

The concentration of the poison does not have to be very large to be lethal. On the lower Mississippi, for instance, there was only 0.054 to 0.134 parts of endrin per billion of water. The victims, mostly catfish, had picked up contaminated silt particles while feeding on the river bottom. They had concentrated amounts as high as 6.0 parts per million in their fatty tissues during the summer; then, as water temperatures dropped in winter, and the fish were feeding less, they absorbed these fatty reserves into their bloodstreams, and with them lethal levels of endrin. In the estuaries,too, the larvae of shrimp were demonstrating a low tolerance to endrin, yet a great ability to concentrate it from mere traces in the water. More than fish were affected. The bayous and backwaters of Louisiana lost countless numbers of turtles, crabs, alligators, and otters, along with cormorants and other waterfowl; to this day the brown pelican, the official state bird, has not returned in any numbers to breed along the coast.

Concerned about the health of the people of the bayous, who subsisted on catfish; about the commercial sale of possibly contaminated fish and shrimp; and about the pollution of drinking water in the city of New Orleans, the United States Public Health Service set up monitoring stations and traced one third of the endrin in the Mississippi to a plant producing the chemical in Memphis, Tennessee, 450 miles upstream. The company was enjoined to clean up a dump which Senator Abraham Ribicoff of Connecticut called a “primitive and dangerous nuisance"; over the past two winters there have been no more catastrophic fish kills. Heavy agricultural use of chemicals on fields of cotton and sugar cane continues in the delta, however, and the runoff into the river has created pockets of prolific, insecticide-resistant mosquito fish, golden shiners, bluegills, green sunfish, and cricket frogs. Here are the beginnings of supercontaminated food chains.

Recently, as the awareness of such dangers has increased, we have begun taking remedial action. In 1964, the Interior Department virtually banned the use of DDT, endrin, and other chlorinated hydrocarbons on all lands it controls. The Dingell-Neuberger Bill, passed by the Eighty-ninth Congress, has increased federal funds for probing the effects of chemicals on wildlife—from a former ceiling of $2,565,000 a year to $3.2 million this year and $5 million in each of the next two years. And attempts are being made to rebuild environments shattered by the careless use of pesticides. Neighboring Canada and our own state of California are taking the lead in experimenting with integrated chemical and biological controls. An example is their use to control aphids, the most prolific of insect pests, in the alfalfa fields of California. Small amounts of Systox (a nonresidual organic phosphate) in the juices of the plants kill only the sucking insects, leaving the predator population healthy. Other enemies, such as parasites and fungi, are then imported to attack the aphids. The result is an artificial balance, maintained without excessive cost, great toxic hazard, or the risk of increasing the pests’ resistance to insecticides.

So, in great ways and little, the battle to save whatever is left of our wildlife heritage goes on. As this is written, the major skirmishes are proposals for the North Cascades and Redwood national parks in the Northwest, which are opposed by mining and logging companies; the “wild rivers” bill, which would preserve “free-flowing stretches of our great scenic rivers” from exploitation; and the controversy engendered by the man-made drought in the Everglades, where a system of locks built by Florida flood control authorities and the Army’s Corps of Engineers has cut off all but a trickle of the normal flow of water from Lake Okeechobee into the Everglades National Park, posing a crucial danger to its wildlife. (In February of this year the Corps announced that the old Miami Canal would be cleared out and extended, but federal funds are still being sought to pay for pumping.)

One of the more hopeful signs noted by conservationists is a bill—S.2435, introduced by Senator Frank E. Moss of Utah—that would redesignate the Department of the Interior as the Department of Natural Resources and consolidate under its control all the scattered agencies that presently govern national parks and forests, lakes, rivers, and wildlife. Currently, forests come under the Department of Agriculture, wildlife under Interior, water-pollution control under Public Health—a compartmentalization that denies any relationship among, say, a watershed, a forest, and fish. Another piece of legislation, one that will supplement the effectiveness of President Johnson’s Wilderness Act, is the Endangered Species Bill recently passed by Congress; it will give the Bureau of Sport Fisheries and Wildlife power to create inviolable refuges for native wildlife threatened with extinction.

These are concrete evidences that Americans are beginning to acknowledge that man is not divorced from but is very much a part of the web of life on this continent. If we are to control nature intelligently, we must learn how wildlife communities work and how they are interrelated. As Secretary Udall recently warned, “every species, being unique, may prove essential in current and future scientific research into the mystery of life itself. Each species is part of the food chain which supports other species. Each has a function to perform. Man … cannot escape the natural consequences of his actions … the sheer power of the population and technological revolutions may make man himself an endangered species in many parts of the earth.”