Connecticut not only provided complete protection for nongame birds but also prohibited the exportation of game birds legally obtained within its borders. This was an attempt to shut down the market hunting that had been so instrumental in eroding wildlife populations, which included of course the extinction of the passenger pigeon. But the wildlife industry rose to protect itself by claiming such a measure improperly poached in an exclusively federal domain by violating the constitutional edict that it is up to Congress “to regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes” (the “Commerce Clause”).
The argument reached the U.S. Supreme Court. In a landmark decision, Justice Edward White wrote the majority opinion in Geer v. Connecticut (1896), which upheld the state measure: states held wildlife in trust for their people and had the power to ensure that harvested game was kept for their benefit; since this state power adhered to all steps in killing and distribution, full private ownership of the game was never attained, thus eliminating this “essential attribute of commerce.” Even though the court clearly stated that whatever rights the states hold in their wildlife must be compatible with “the rights conveyed to the federal government by the Constitution,” the decision gave ammunition to those who later claimed that any national laws abridging what states could do with their own wildlife were a breach of the commerce clause.16
But the federal government was extending its involvement in the promotion of conservation. The U.S. Commission on Fish and Fisheries was founded in 1871 to address depleted fisheries. President Theodore Roosevelt established the first national wildlife refuge in 1903. The first regulatory statute, though, was enacted in 1900. It became known as the Lacey Act, in honor of the Iowa congressman who toiled for years on behalf of bird protection. The law targeted the trade in wildlife that originated in states where its killing was legal but was exported into states where it would have been illegal. Under Lacey the legal status of all game entering a state would be based on the laws of the receiving state. Unfortunately, even with the Lacey Act, as long as some states refrained from passing adequate restrictions, interstate wildlife marketing would continue.17
The recognition that only the national government could provide effective relief for migrating animals, here today and gone tomorrow, led to the passage of the Weeks-McLean Act. Pioneering bird photographer and Pennsylvania congressman George Shiras III first introduced the legislation in 1904, but resistance to the idea that migratory wildlife was within the purview of the national government delayed enactment until 1913. Two federal district courts found it unconstitutional, but before the Supreme Court could weigh in, the United States and Great Britain, on behalf of its possession Canada, signed a treaty that protected the birds migrating across the national borders. (The United States would later sign similar agreements with Japan, Mexico, and the former Soviet Union.) To ratify the treaty, Congress passed the Migratory Bird Treaty Act, which was virtually identical to Weeks-McLean. The high court dismissed the case against Weeks-McLean but soon visited the issue in Missouri v. Holland (1920), which challenged the new law as an improper usurpation of states’ rights. Justice Oliver Wendell Holmes wrote a characteristically memorable decision: “To put the claim of the State upon title [to birds] is to lean upon a slender reed. Wild birds are not in the possession of anyone … But for the treaty and the statute there soon might be no bird for any powers to deal with.”18
One other early law is worth noting. In 1913 the Wilson Tariff Act stopped any further importation of wild-bird feathers for hats or other business uses. Along with Lacey, it was subsequently changed to ban the importation of wildlife that was obtained or exported illegally from the country of origin. These amendments represent the first time the laws of one country were used to help the effectiveness of another. Both laws provided the underpinnings of the U.S. Endangered Species Conservation Act (1969) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the principal legal bulwarks in the nation’s efforts to protect and recover imperiled plants and animals.
Congressman Lacey’s words from 1900 ring loud and clear.
With regulated hunting and the establishment of public refuges and preserves at all levels of government, wildlife in general increased dramatically, and certain species on the precipice of extinction moved to safer ground. If the passenger pigeon is the icon of an animal driven to extinction through deliberate, wanton, and direct human actions, the continued existence of other species proves that these new conservation measures were effective. Bison now roam throughout the west and have become agricultural products as privately held herds are managed like cattle for meat production. Great egrets, plundered for their nuptial plumes and restricted to a few isolated or protected rookeries in the Deep South, rebounded and now occupy their former territory throughout the eastern United States. The heaviest of North American birds, the trumpeter swan, retreated before the gun and dredge to make its last stand at a few remote locations in Montana, Wyoming, Alaska, and western Canada. In 1933, the lower forty-eight states harbored only sixty-six of the swans, all in the Yellowstone area. Under close protection, however, their population is now pegged at sixteen thousand, enabling the species to reclaim lost range; augmented by introductions, trumpeter swans again inhabit parts of the Great Plains and Midwest after an absence of 150 years.19
As time passed, the technologies needed to sustain growing human populations took new forms. Other threats to biodiversity emerged or at least became serious enough that they could no longer be ignored. Rachel Carson’s clarion call in Silent Spring alerted the populace that products whose last four letters are based on the Latin word for “kill” (cide) are often less selective than claimed by their manufacturers. The broader implications that modern industrial societies sullied the air and the water with poisons as a matter of course led to the second great environmental movement of the late 1960s and early 1970s.
Again laws were enacted and toughened. In the United States these included the Clean Air Act, Clean Water Act, National Environmental Policy Act, and the Endangered Species Act (1973). Canada passed the Environmental Protection Act and the Species at Risk Act, among others. The banning of certain pesticides in North America and the improvement in water quality have done wonders for such fish-eating birds as ospreys, bald eagles, double-crested cormorants, and white pelicans. White pelicans now nest farther east than the historical record indicates they ever did previously.
Actions under the Endangered Species Act have contributed to the “recovery” of twenty-two species or subspecies of plants and animals, including Eggert’s sunflower (Helianthus eggertii), peregrine falcon, grizzly bear, most populations of gray wolf, and all but one population of bald eagle. Other organisms have experienced increases in population even if their long-term survival is still uncertain; black-footed ferret, Big Bend Gambusia (a small fish, Gambusia gaigei), whooping crane, California condor, and Kirtland’s warbler are five examples.
The Kirtland’s warbler is an unusual case. Its survival depends on government largesse. As far as anyone knows, it was always rare, for its geographic range is largely limited to the northern part of Michigan’s Lower Peninsula (a small number of birds now nest in the Upper Peninsula, Wisconsin, and Ontario). Within that circumscribed area, the warbler breeds almost exclusively in jack pines (Pinus banksiana) between five and twenty feet in height. Add to those narrow habitat requirements heavy parasitism by brown-headed cowbirds, which routinely lay their eggs in the nests of the warblers, and you have a formula for extinction. But because of intensive cowbird control and habitat management costing over a million dollars a year, this distinctive bird has a future.
The mere passage of legislation does not, of course, prevent all extinctions. Take the dusky seaside sparrow (Ammodramus maritimus nigrescens), the only animal I have seen that became extinct. When I added the bird to my life list in June of 1972, it inhabited a paltry section of brackish marshland near Cape
Kennedy, Florida. As a birder, I was disappointed when it was later relegated to the status of a subspecies of the much more widely distributed seaside sparrow. Fortunately it was not abandoned, although what efforts were expended on its behalf bore no fruit. But its story illustrates well how much the forces of extinction have changed since railcars filled with wild-pigeon carcasses rolled out of Petoskey.
You might say the dusky seaside sparrow was an unintended casualty of mosquito control, collateral damage in military parlance. Dousing of the bird’s habitat with pesticides reduced its population substantially. No doubt the poison also aided in the control of the pesky insects, but apparently not enough to make the environs of the Kennedy Space Center comfortable to personnel. To move forward with the jihad against mosquitoes, a large part of the remaining sparrow range was flooded. Then, to widen a highway, the little bit of marsh that still held the few sparrows was drained. By 1979, the world population of dusky seasides numbered six, all males. Four years later, the four survivors were taken to the Disney World Resort, where attempts to breed them with another dark race of seaside sparrow failed. The end came on June 17, 1987, almost fifteen years to the day after I saw them. I have always thought that the last of a species should never expire at Disney World, but at least he was never put on display where the public could throw sand to make him move, an indignity to which Martha was subjected.
Now, as we approach the centenary of the passenger pigeon’s extinction, most scientists agree that we are currently in the early to mid stages of the planet’s sixth great episode of mass extinctions. (This is despite the laws and advances in knowledge.) Not only does this episode differ from previous ones in being caused by one species—some refer to human activities as the modern analogue of the asteroid that destroyed the dinosaurs—but it has resulted in the “loss of larger-bodied animals in general and apex species in particular.” Apex species are predators that have no predators themselves and reside at the highest trophic levels (they inhabit the top of the food chain). Their elimination is especially pernicious because it can profoundly alter the ecological structure and dynamics of ecosystems, including such things as fire frequency, disease, invasive species, and biochemical processes.20
A report from the International Union for Conservation of Nature in 2010 says that 30 percent of amphibians are at risk of extinction; 21 percent of mammals, reptiles, and fish; and 12 percent of birds. The Alliance for Zero Extinction has identified 131 mammals, 23 coniferous trees, 15 reptiles, 217 birds, and 408 amphibians from across the world that face imminent extinction. Nature Canada lists 631 species facing extirpation in their country, while authorities in the United States officially recognize nearly 1,100 plants and animals facing the same fate in their nation. Slightly more secure are 295 species deemed to be only threatened.
Biologist David Blockstein refers to the Four Horseman of modern extinctions: habitat loss, direct take, pollution (which would include pollution-induced climate change), and introduced species. Each of these can be devastating to a particular group of species, but these factors are not operating independently. Often, an interplay between them exacerbates the effects of any one. It is important to keep this in mind as we discuss briefly the anthropogenic forces that are ridding the planet of its biological richness.21
Habitat loss is impossible to miss, for modern human societies consume tremendous amounts of space. Landscapes once harboring a multitude of living things are covered with buildings, roads, and croplands that ooze across the countryside with nearly the same lethality as molten lava. Mining and unsustainable forestry practices gobble up ground in the hinterlands. From the perspective of most plants and animals, humans make terrible neighbors. Relatively few organisms find these new circumstances hospitable and proliferate, often to the detriment of less common species. But many more find that these changes make it impossible to execute life’s necessary functions. Habitat loss is generally deemed to pose the greatest risk to biodiversity.
One subset of habitat loss that carries its own special type of threat is the imposing structures that we design and construct. Tall buildings are monuments of prestige and wealth. But when well lit during periods of migration or veneered with reflective glass, they become deadly obstacle courses for birds and bats. One biologist concluded that only habitat loss claimed more avian lives than collisions with buildings. Communication towers potentially threaten air traffic, so those higher than two hundred feet or near airports must be lit, but that illumination, particularly when it is red, increases crashes of another kind: millions of birds, of which various warblers, including the rapidly declining cerulean, are among the principal victims. If the construction of wind turbines, an environmentally friendly energy source, continues to expand as projected, a million more birds may die per annum. Bats are not faring too well either, as their corpses have been found at almost every wind facility in North America where adequate studies have been conducted.22
While regulated hunting is unlikely to cause extinctions, illegal taking of species whose carcasses bring high prices continues to plague conservation efforts on behalf of such animals as the tiger and several species of rhinoceros. In the case of horseshoe crabs, overharvesting along the Mid-Atlantic coast of the United States has not only reduced the crabs but is damaging shorebirds, particularly the red knot, that rely on an abundance of crab eggs for food before embarking on long flights to arctic breeding grounds.23
But the most egregious examples of profligate slaughter, reminiscent of the type that so ravaged wildlife in the nineteenth century, occur where there is no state authority: the open ocean. Factory vessels equipped with immense seines can remove virtually all life larger than its meshes from a column of water that reaches from the surface to the bottom. Catches of the five most coveted species of tuna, for example, have increased from a million tons a year in the mid-1960s to over four million currently. These species are now deemed to be threatened or nearly threatened with extinction by the International Union for Conservation of Nature. But where there is no authority to stop them, players are free to plunder. Only international cooperation can spare the commons from becoming defiled and depauperate. Yet with the world population of people topping seven billion, that kind of voluntary restraint seems like a daydream.24
Pollution is a seemingly unavoidable concomitant of human aggregations that only increases with population size and standards of living. Specific contaminants can be regulated or banned, but the pernicious effects of spewing forth pollutants in huge quantities is felt across the globe. Aquatic ecosystems are perhaps most vulnerable as the introduction of pollutants renders the water unfit for life. This effluent can kill outright or negatively impact long-term health by altering reproductive capacity, creating specific illnesses such as cancer, reducing oxygen levels and water clarity, compromising immune systems, increasing levels of acidity … and the list continues. Even the oceans, the planet’s least vulnerable repositories of liquid water, are being sullied to dangerous levels: they are beginning to manifest what appears to be impending biological impoverishment beyond what humans have ever experienced, and the time to implement effective and rapid remedies is fast ebbing.
As the industrial world has dumped untold tons of carbon into the air for centuries now, we have triggered yet another profound challenge to the maintenance of biodiversity. The effects of climate change are just beginning to be felt and are most pronounced at high elevations and in the Arctic, where the warming is apt to be greater than in other regions. Whitebark pines (Pinus albicaulis), a keystone species of subalpine forests, inhabit western Canada and the United States, but are fast disappearing as temperatures rise and moisture decreases. These changing conditions favor competing trees and make the pines more susceptible to fatal infestations of mountain pine beetle (Dendroctonus ponderosae) and white pine blister rust (Cronartium ribicola), a native of Europe. Fire suppression by land managers also allows expansion of competing trees at the expense of whitebark pines.25
The Arctic Climate Impact Assessment projects that warming will reduce summer sea ice by roughly half in less than a century. This will likely prove devastating to a host of animals that require ice for resting, feeding, or denning. Such charismatic species as polar bears, ribbon seals, walrus, and ivory gulls are among those that would be affected. One known victim of climate change is the terrestrial Peary caribou (Rangifer tarandus pearyi), an inhabitant of the high arctic islands of Canada. This herbivore survives by using its unusually pointed hooves to reach food plants buried beneath the snow. But freezing rains and a change in melt-thaw cycles, both caused by a greater number of warmer days, have led to the formation of ice layers that stymie efforts at foraging. This is believed to be a major reason behind the caribou’s population crash: from twenty-six thousand in 1961 to seven hundred in 2009. Increases in ice and crusted snow have also adversely affected such other arctic land mammals as musk oxen, lemmings, and voles.26
A Feathered River Across the Sky Page 26
