Some years ago I went along on a pack trip into the high pine country of the Sierra Madre in northern Mexico to look for the Imperial Ivory-billed Woodpecker. My companions were John Rowlett and Victor Emanuel, both highly qualified bird watchers who now lead nature tours. The bird we were looking for was a huge woodpecker, the world’s largest, almost two feet in height, the size of a raven. The bird was thought to be extinct—not seen authoritatively since 1954, when a dentist named W.L. Rheim spotted a pair 100 kilometers south of Durango; four years later, returning to the Sierra Madre, he met an Indian on the trail carrying a dead Imperial, very likely one of the pair he had seen earlier.
Nonetheless, the occasional rumor that the bird had been spotted gave us hope, and so did the vast stretches of pine forest: it seemed inconceivable that the woodpecker was not in there somewhere. Rowlett had learned from tapes the call of the American Ivory-bill, which was thought to be close to the Imperial’s, and he would stand on the ridges, hands cupped to his mouth, and call into the pines. No reply. A day or so before we backpacked out, we met a logger who had eaten an Imperial Ivory-bill fourteen years ago. He told us this with a broad innocent smile, a gold tooth shining in it. Victor, translating from a rush of Spanish, said, “He tells me that it was un gran pedazo de carne—a great piece of meat.”
The reasons for the woodpecker’s decline were evident enough. Not only was it shot as a campfire delicacy and its feathers used to decorate Indian headdresses, but for a pair to breed successfully, it needs an enormous, undisturbed tract of pine forest—probably as much as 2,000 acres. From time to time we could hear, if the wind through the pines was right, the thin, high whine from a sawmill settlement named Pescadores.
The sad lot of the Imperial Woodpecker came to my mind while reading Birds in Jeopardy by Paul R. Ehrlich, David S. Dobkin, and Darryl Wheye. The Imperial is not mentioned since the authors have restricted their listings to the “imperiled and extinct birds” of the US and Canada, including Hawaii and Puerto Rico. But the authors discussed our own smaller, native Ivory-billed Woodpecker (Campephilus principalis), which will be declared extinct this year unless documented proof of its existence is produced. Its last known population was in the 120–square mile “Singer [Sewing Machine Company] Tract” along the Tensas River in Louisiana. In 1948 the area was cleared for soybean production.
Thus, almost surely, the Ivory-bill will join four species native to the continental US and Canada which have become extinct—the Labrador Duck; the flightless Great Auk, a bird so tame that it could be herded across gangplanks into holding pens aboard ship; the Passenger Pigeon, once so abundant that it was though to account for one fourth of all American land birds (the ornithologist Alexander Wilson once estimated that a sky-darkening flock he saw contained two billion birds). And yet the pigeon was so overharvested that by 1913, only a single specimen was left—a female named Martha, who died that year in the Cincinnati Zoo. The decline and disappearance of the Passenger Pigeon was matched by that of the Carolina Parakeet, the only member of the parrot family native to the US, a beautiful bird but an agricultural pest. The last two specimens (Lady Jane and Incus) died in 1917, in the same zoo where a breeding program had kept the species going for twenty years.
One could very well add to those four not only the Ivory-bill Woodpecker, but also Bachman’s Warbler, whose last confirmed sighting was in 1962, and the Eskimo Curlew, also last seen in 1962, on Galveston Island, Texas. Three years before, my friend Victor Emanuel had seen the bird in the same vicinity, quite likely the identical one. He said it was like “seeing a dinosaur.” Since then there have been a sprinkling of sightings, the last in late May 1987 when Canadian Wildlife Service biologists reported a pair of Eskimo Curlews in the Canadian Arctic—which suggests at least the possibility of a nest.
Definitely lost are at least five American subspecies.* These include the Heath Hen (which died out on the island of Martha’s Vineyard in the 1920s), San Clemente Bewick’s Wren, a Texas race of Henslow’s Sparrow, the Santa Barbara Song Sparrow, and the Dusky Seaside Sparrow, the last purebred of its subspecies (named Orange) having died in 1987 at the age of thirteen at Florida’s Disney World.
One might suppose that this is not too bad a record—the loss of just seven species and five-odd subspecies in so vast a country since, say, 1776. But it doesn’t take more than a glance or so at Birds in Jeopardy to realize that there is very little to rejoice about, and much to give concern.
The authors first describe the seventy birds (species and subspecies) in the US, Puerto Rico, and Canada considered by the Endangered Species Act of 1973 to be “endangered” (in imminent danger of extinction) or “threatened” (likely soon to be in such danger)—the Whooping Crane, Least Tern, Red-cockaded Woodpecker, the Northern Spotted Owl, Kirtland’s Warbler, and Everglade Snail Kite are on this list. Next is a selection of eleven vulnerable but not officially listed birds (the Golden Eagle, the Harlequin Duck among them), followed by the seventy birds on either the Audubon Society’s “early warning” Blue List or the society’s auxiliary list of birds warranting “special” or “local” concern. Bird watchers will be surprised by some of the entries here—the Great Blue Heron, the Turkey Vulture, the Common Loon, and the Black-crowned Night Heron, for example—relatively common birds that are listed because they are declining in specific regions. Last, there is a melancholy list of the birds already extinct, including twenty-three formerly from the Hawaiian Islands.
The most dismaying chapters in the book describe the natural history of Hawaii, truly an ecological convulsion. When the first explorers from the Polynesian islands stepped ashore 1,500 years ago, the only mammals there were the monk seals, which thronged the beaches, and a single species of bat; there were no mosquitoes, lizards, or snakes. Now it has been estimated that half of Hawaii’s rich original flora and fauna has gone—done in by an appalling combination of deforestation (conversion for agriculture), avian pox, habitat destruction (rooting, browsing, and trampling by deer, rabbits, sheep, and goats—all introduced into the islands).
Ironically, introduced birds have also had a hand in the ravaging—among them the Japanese White Eye, the Common Myna, feral parrots, even the superbly named Melodious Laughing Thrush, as well as others, crowding out native birds. Indeed, Hawaii’s state bird, the Hawaiian Goose, more commonly called the “nene” (a name familiar to crossword puzzle addicts) is down to a population in the wild of about 500 owing to encroachment on its nesting grounds by the Ring-necked Pheasant, yet another “introduced” bird.
Perhaps the most horrifying episode of introduced destruction has recently been taking place on the nearby mid-Pacific island of Guam. At some point during the Vietnam War, military equipment being shipped back from the war zone inadvertently carried with it the occasional Brown Tree Snake, a relatively small (three to five foot) resident of Southeast Asia. In the late 1960s, scientists on Guam began to notice the thinning of bird populations—at first thought to be caused by the spread of avian pox. Then in the 1970s, it was noticed that a map overlay showing the Brown Tree Snake population burgeoning across the island matched the very areas where birds were diminished. By the 1980s, the tree-climbing, egg-eating snakes, crafty enough to take a female bird off its nest, had completely wiped out three species, the Guam Broadbill, the Bridled White Eye, and the Rufous-fronted Fantail, and had brought to the brink of extinction two others.
In a survey conducted in 1988 it was estimated that up to seven million snakes were on the island. With no natural enemies and plenty to feed on, they not only proliferated in numbers but also in size: specimens were taken that were thirteen feet long, large enough to prey on chickens and the occasional small dog. It required a kind of zoological airlift (operated by the so-called Eastern Zoos—the New York Zoological Society and the Washington and Philadelphia zoos) to get species of birds off Guam before the snakes finished them off entirely. The hope was to save them from extinction with breeding programs—such as is now being with the California Condor.
One of the birds evacuated from Guam was the Micronesian Kingfisher—middle-sized, tan-backed, dark-winged, white-fronted. Seventeen kingfishers were retrieved, and though the species is an especially difficult bird to get to breed, their numbers have since increased to seventy-five. The breeding program for the Guam Rail, a shy, furtive bird that frequents the reed swamps there, has been more successful—its numbers increasing to as many as 250. A few of them have been reintroduced to Rota, a small island a couple of miles off the coast of Guam.
The Bronx Zoo has a pair of Micronesian Kingfishers. I paid them a visit not long ago. As might be expected, they live in relatively sumptuous quarters in the Bird House: a stream meanders beneath a pine-branch perch. I saw only one bird—the female may have been hidden in a nest cavity. The male remained motionless for the time I stood watching. If he had not ruffled his feathers at one point he could well have been a stuffed specimen…and indeed he had come very close to exactly that, the last of his breed, and settled into a habitat group downtown in the American Museum of Natural History, perched above a motionless stream of glass.
As for the situation in Guam, with the food supply dramatically diminished (rodents and lizards, among others, were affected along with the birds), the snake population has slacked off. But the damage they have done in the Pacific may not be finished. Every plane from Guam that lands in Hawaii is searched for the Brown Tree Snake, especially the landing gear recesses into which this nocturnal snake will crawl to escape the heat of the day. A number have already been killed on the tarmac of Oahu’s International Airport.
Thirty-two Hawaiian birds are listed in Birds in Jeopardy as threatened or endangered, with a couple of “candidates” close to making the list—the Bristle-thighed Curlew and Bishop’s ‘O’o. A few years ago Victor Emanuel and I were considering an expedition to the island of Kauai to look for the Kauai ‘O’o (Moho braccatus) also known as the ‘O’o’a’a. We mouthed the names with delight. It is one of the honey creepers and the last of its genus thought to have survived—this because of its habitat in the dense rain-drenched forests of the Mahai Swamp. Little is known about the bird. One of the few descriptions portrays its behavior in the thick leafy foliage as “acrobatic.” The first ‘O’o’a’a’s nest (in a tree cavity) was only discovered in 1971. Victor had a report—little more than a rumor—of a sighting of two birds in the swamp, both females. That these were likely the only representatives of the species was such a melancholy thought that my enthusiasm waned. We called off the expedition.
Because of the density of its habitat and its secretive behavior, it would have been impossible to chronicle effectively the slow demise of the ‘O’o’-‘a’a. But this has been done in exemplary fashion about the last days of Florida’s Dusky Seaside Sparrow in Mark Jerome Walters’s haunting book, A Shadow and a Song.
Darkly plumed, with black or mottled streaks across a white breast, the Dusky is distinguished by its near-thrushlike markings—“a standout among the usual drab brown and grays of the sparrow family.” Its troubles began when the Kennedy Space Center was established on the Canaveral Peninsula in the 1960s. Unfortunately, the birds’ range was extremely limited—confined to two colonies in Brevard County near the gantries of the Space Center: one on Merritt Island, the other ten miles inland on the St. Johns River. In 1831 John James Audubon wrote, in a dire foreshadowing of the bird’s poor standing in humankind’s eyes, “Having one day shot a number of these birds, merely for the sake of practice, I had them made into a pie, which, however could not be eaten, on account of its fishy savour.”
Ornithologists estimate that two thousand pairs of the sparrow once lived on Merritt Island. By 1957, as part of NASA’s program to improve areas adjoining the Space Center, the pesticide DDT, used for mosquito control, had reduced the number by 70 percent; the draining of the marshes—also a mosquito-control measure—brought the birds to the brink of extinction. Measures were suggested at the time that might have saved the species. A young biologist, Charles Trost, recommended that adjustable gates could be built into the dikes to flood the marshes during the peak mosquito breeding seasons, and then used to drain them for the rest of the year—saving not only the sparrow but the unique local ecosystem. When the engineers of mosquito control ignored the recommendations, the salt marshes quickly changed into a completely different habitat—one of cattails, Red-winged Blackbirds, Boat-tailed Grackles. And ducks. As one official observed, “We improved the habitat for ducks but blew it for the Dusky.”
This must have caused mixed feelings in Jim Baker, the man from the Fish and Wildlife Service picked to lead the Dusky Seaside Recovery program. Baker, an expert on ducks, was an avid hunter, partially deaf in his right ear from shotgun blasts. His nickname, “Big Gizz,” was from the thousands of duck gizzards he had opened looking for bird shot in the course of his studies of lead’s effect on waterfowl. He knew nothing about the sparrow. “What is the Dusky like?” he asked an ornithologist friend. “Is it anything like a house sparrow?”
The team Baker headed reflected Fish and Wildlife policy shortly after the Endangered Species Act of 1973 was passed—which was to appoint specifically assigned recovery teams to deal with each endangered species. The team was not as professional as it could have been. Brian Sharp, a young graduate student in wildlife biology, and an expert on the Dusky problem, was not chosen because he and his wife had been caught skinny-dipping on Merritt Island years before. The question was asked: “Is this the kind of employee Fish and Wildlife wants?”
Two years after its formation in 1975, Baker’s group finally produced a “recovery” plan. It was only fifteen pages long (a portion of it maps and a bibliography) and painfully obvious: “Develop public awareness of the Dusky.” Several years later, the Fish and Wildlife Service approved the plan and then shelved it: by that time the sparrow had been reduced to four males of the St. Johns population. The only hope for the Dusky was to capture the four birds and increase their numbers through hybridization—crossbreeding them with females of a closely related seaside sparrow from the Florida Gulf Coast known as Scott’s Seaside Sparrow. In theory, an almost pure Dusky could be created by a procedure known as “back-crossing.” After five generations a 97 percent Dusky could be evolved, and when the numbers were sufficient, presumably reintroduced into the wild.
Some people in Florida were willing to help—among them, surprisingly, the executives at Disney World, who said they would provide facilities for the backcrossing program in carefully designed pens on Blackbeard’s Island, close by Cinderella’s Castle. In return they asked that any hybrids from the program be given the scientific name Ammospiza maritima disnei, a request that was eventually turned down by the Fish and Wildlife Service.
The press was also interested. When the crossbreeding program was announced, The Miami Herald pointed out that Disney World was “indeed a fantasy land where dreams almost always come true.” Alas, in this case the Herald was not prophetic. Because of the Duskys’ advanced age, almost all attempts at breeding with the female Scotts resulted in infertile eggs. The few successes were soon lost through neglect or ill-fate. The four sparrows (Orange, Yellow, White, and Blue, named after their colored plastic leg bands) finished their days in the Blackbeard Island aviary—every afternoon being fed ten crickets and five mealworms. An attendant played their song on a cassette to get them to respond. The last of the Duskies, Orange, died in 1987. In his final days, as Walters described him, “He never sang naturally, as there were no other duskies to cause him to defend a territory. This is what…his keeper noticed most. Only when they brought the same minute-long tape that he had heard hundreds of times before, was Orange coaxed into song.”
To administer the Fish and Wildlife Service programs for saving endangered species requires from the Congress about $50 million a year, supplemented by an equivalent amount from twelve other Federal agencies and individual states. Environmentalists scoff at those who consider these sums excessive. Michael J. Bean, chairman of the Environmental Defense Fund’s Wildlife Program, once pointed out to me that $45 million is being spent to repair a single bridge over the Potomac. Every year the Fish and Wildlife Service publishes a thick volume describing in detail how the millions authorized are spent on the 684 species (birds, plants, and insects) at present on the threatened and endangered list.
The expenditures for a specific program often change dramatically from one year to the next. Heading the 1990 list, as might be expected, is the Northern Spotted Owl—which received $9,687,160. It is followed by Bell’s Vireo ($9,168,800), the Grizzly Bear ($5,882,540), the Red-cockaded Woodpecker ($5,195,030), the Florida panther ($4,113,850), the Mojave Desert tortoise ($4,091,400), the Bald Eagle ($3,510,740), the ocelot ($2,980,200), the Jaguarundi ($2,893,100), and the Peregrine Falcon ($2,873,320). These species received almost half the total allotment. What was left was portioned out in decreasing sums, the last on the list of those receiving funds being the Lee Pincushion Cactus, which received $100. The first fish that appears on the list, incidentally, is the Chinook Salmon, allotted $2,306,470 to help it get up the Sacramento River to spawn. The top plant is the Northern Wild Monkshood ($226,020); of the snakes, the San Francisco garter ($40,900); the leading beetle is the Valley Elderberry Longhorn ($951,600).
I called the Fish and Wildlife Service to ask about the American Burying Beetle, which has long fascinated me. Receiving $97,130, it has had a most curious, indeed puzzling, history: once widespread in the eastern United States it now only occurs in two far-flung sites—on Block Island off the Rhode Island coast, and a small tract thousands of miles away in Oklahoma. Scientists have no idea what caused its almost total disappearance or the reason for its survival on locales so far apart.
I reached a Fish and Wildlife representative, Susie Von Oettinger, who specializes in the Burying Beetle. “Oh, it’s beautiful,” she exclaimed rapturously. “Shiny black, with scalloped orange-red markings on the back, and orange-colored feelers.” Then she hastened to say this: “I don’t look at just the beetle, though, but at the ecosystem…and how the beetle affects it…turning over the soil…cleaning up the carrion.”
She talked about the “Recovery Plan” for the beetle, including protecting and managing the extant population (thought to be less than 1,000 specimens in the two widely separated locales), maintaining two laboratory colonies, sponsoring efforts to reintroduce it elsewhere, searching for additional populations, and, of course, research into the species’ decline. For this, perhaps pesticides were responsible, Ms. Von Oettinger said. Or perhaps the beetles’ food base—especially gull chicks and field mice—had been ravaged by raccoons and skunks. The most original hypothesis was that the beetle’s disappearance was linked to that of the passenger pigeon—the litter beneath its vast nesting areas had provided an ideal habitat for them.
But—she had news to tell me—a bug-collector in Nebraska had brought in a single specimen. “Where there’s one, there’s got to be more!”
In the 1880s a study by the New York Zoological Society estimated that in twenty-eight states, the District of Columbia, and the Indian Territories bird populations had decreased by 46 percent. Theodore Roosevelt wrote the distinguished naturalist Frank Chapman: “When I hear of the destruction of a species I feel just as if the works of some great writer had perished, as if we had lost all instead of only part of Polybius or Livy.” Public concern was limited. The so-called “Bands of Mercy,” organized in 1884, had a quarter of a million members, but most of them were children, who wore pins that read “Kindness to all harmless living creatures.” More effective was the Audubon Society, organized by the American Ornithologists Union in 1886 “for the protection of wild birds and their eggs.” The society, of course, has had a considerable impact over the years—notably the campaign in 1913 which led to the banning of egret feathers for women’s hats, almost surely saving the species from extermination. In more recent times, the most important force for saving species, however, was Rachel Carson’s Silent Spring of 1962, with its memorable opening paragraph:
It was a spring without voices. On the mornings that had once throbbed with the dawn chorus of robins, catbirds, doves, jays, wrens, and scores of other bird voices there was now no sound; only silence lay over the fields and woods and marsh.
What had stilled the voices were the pesticides of the time, specifically DDT, which though it didn’t kill birds outright disrupted the calcium metabolism in their bodies and caused the thinning of egg shells, so incubating birds simply broke the eggs when they sat on them. Carson’s book, and the public concern it ignited, eventually led to changes in the practice of insect-control spraying; within two decades many of the bird populations most seriously decimated by pesticide use—the Brown and White Pelicans, the Bald and Golden Eagles, the osprey, and the Peregrine Falcon in particular—have made a substantial recovery. Still, pesticides continue to be a major problem. Many species of birds migrate to and from regions of the southern hemisphere where DDT-spraying is not illegal: the authors of Birds in Jeopardy estimate that one in five listed endangered species is threatened in part by pesticides.
Another grave problem for the American bird population has been the destruction caused by species introduced into the US, many by well-meaning but ill-informed organizations. During the mid-nineteenth century a number of “Acclimatization Societies” were organized to bring over birds from abroad. They did so partly for aesthetic reasons (homesick for the song of the skylark, say), but partly for sport, and to provide food for the table (the Ring-necked Pheasant, the Hungarian Partridge), and also for practical purposes: the English (or House) Sparrow was introduced in the hope it would get rid of a pest called the dropworm. Until the Lacey Act forbidding this kind of import was passed in 1900, the societies introduced large numbers of nonindigenous species—among them songbirds such as Japanese finches, Dunnocks, Linnets, English Blackbirds, wood larks, skylarks, European siskins, Chaffinches, European goldfinches, nightingales, and the European Great Tit.
Mostly, the programs failed. Between 1872 and 1874, the Cincinnati Acclimatization Society released twenty different species, three thousand birds in all. None of them adapted. The growing skylark population in Brooklyn was wiped out by the blizzard of 1888. Nightingales were brought in by the thousands but none of them made it. The novelist Marjorie Kinnan Rawlings writes engagingly in Cross Creek of a nightingale importation tried by Edward Bok for his tower sanctuary south of Orlando, Florida. An elderly caretaker told her that the nightingales had died for lack of proper food, or perhaps from home-sickness, but that in the meantime the mockingbirds had learned their songs, and according to the caretaker, their versions were lovelier than the originals.
The acclimatization societies had a few successes but when they did, the consequences were hardly what was hoped for. The English Sparrow may have taken care of the dropworm, but it caused such misery to local birds—crowding out robins, cardinals, bluebirds, martins, and native sparrows—that Frank Chapman stated in 1902 that they would “take over the country.” He had terrifying supporting evidence from the US Department of Agriculture in which someone had figured out that a single pair of English Sparrows could in ten years produce offspring numbering 275,716,983,698. Fortunately, when the horse, whose manure contained the undigested seed that the birds doted on, was displaced by the automobile, the sparrows’ urban populations declined.
Alas, that was not the case with the starling. Its arrival was engineered by Eugene Schieffelin, a rich drug manufacturer, who, with a fellow-member of the American Acclimatization Society, had the quaint notion of introducing the forty-odd birds mentioned in the Shakespeare plays to the United States. Many of the birds in the canon, of course, were already in the US: ravens (which turn up in fifteen of the plays), Golden Eagles (thirteen), wrens (four), Goshawks (two), a single Osprey (Coriolanus). Of the owls (mentioned in eight plays) the Barn Owl is the same on both continents, but most other owls are not. The starling is mentioned only once in Shakespeare (“I’ll have a starling shall be taught to speak nothing but Mortimer…” Henry IV). Schieffelin let loose two flocks in New York City’s Central Park, one in 1877 and then one in 1890.
Ironically, the first pair to nest did so in the eaves of the American Museum of Natural History. The starling’s numbers grew alarmingly. It began to compete successfully with other birds that nest in cavities—woodpeckers, martins, bluebirds—decimating their populations. Its appetite was voracious and hardly as picky as the House Sparrow’s—nothing like the decline of the horse could impede its growth. Its flocks darkened the skies over the cattle-feeding pens of the Midwest. It became an urban pest—its gigantic fall and winter roosts, raucous and foul, become the bane of community officials whose efforts to dislodge the birds with fake owls, bell-clanging, periodic explosions, and electric shocks all failed. The bird has become a permanent fixture of the US landscape.
Oddly, the bird that has caused the most damage to existing avian populations is an indigenous species—the Brown-headed Cowbird. Two centuries ago the cowbird was relatively uncommon. It accompanied the vast bison herds of the Plains, scavenging seeds from the dung-heaps, but with the increase of cattle-ranches and open farmland in formerly forested areas, the cowbird populations began to increase startlingly. Their food supply was plentiful—particularly in the fields where mechanical harvesters had spilled seeds. John Terborgh in Where Have All the Birds Gone? believes that the cowbird could very well be responsible for driving more birds to the edge of extinction, at least in the immediate future, than even the huge rain forest loss going on in the tropics.
The cowbird is a parasitic species: the female lays her eggs in other birds’ nests. When the cowbird young hatch, they are fed by the unsuspecting foster parents and almost invariably crowd out the true offspring. Years ago the cowbird didn’t pose so much of a threat. In precolonial times, spooked by deep forests, it parasitized only fifty or so host species. But with the clearing of forested areas for cultivation or real estate, and the increase in forest edge habitats, which the cowbird (as well as feral cats and raccoons) prefers, it is now estimated that approximately two hundred species of host birds are affected. Many of these are especially vulnerable because they don’t have the innate defenses of such birds as the phoebe, which has been genetically programmed to recognize a cowbird egg. It often dumps it over the side of the nest or builds a second floor over it.
The greatest losses to cowbird infestation have occurred east of the Mississippi. In certain regions, some of the long-distance migrants, especially the Hooded Warblers, Wood Thrushes, and Red-eyed Vireos, have suffered parasitism by cowbirds in eighty out of a hundred nests. One of Terborgh’s associates found that in Illinois “wood thrushes are doing nothing but raising cowbirds.” Already, Kirtland’s Warbler, the Black-capped Vireo, and Least Bell’s Vireo have been nearly wiped out by cowbird parasitism, and other species are sure to be victimized as well.
Of course, countermeasures are being tried. Under the auspices of the Fish and Wildlife Service a cowbird-trapping program may save Kirtland’s Warbler, a blue-backed, yellow-breasted warbler noted for its loud and melodious song (described by my friend, the naturalist-writer Peter Matthiessen, as sounding like “Felicity-has-to-wee-wee”). The bird, very localized, lives in the jack pine country at the northern end of Michigan’s Lower Peninsula, and is especially bothered by the cowbird infestation because it takes an unusually long time to incubate its eggs, longer than any other North American warbler. In 1987 a count of the males singing their urgent song was down to 167. Thirty-eight cowbird traps were set, a trap every square mile—large chicken-wire structures baited with grain, cowbird decoys in each, with slots at the top through which birds with their wings folded could drop in to join the party but not fly out. As many as eight thousand cowbirds have been trapped annually, and killed by truck exhaust piped in to closed pens. The Kirtland’s Warbler count has risen—last year almost four hundred males were counted—but so has the number of cowbirds trapped. It is a program that will have to be continued if the warbler is to survive.
As if that weren’t enough, on its way from South America—like the killer bees and the fire ants—is another species of cowbird called the Shiny Cowbird. It has moved north through the Caribbean, wiping out nearly all of Puerto Rico’s Yellow-shouldered Blackbirds en route, and is extending its range into Florida, Louisiana, Alabama, the Carolinas, Texas, and Oklahoma—a situation which offers the possibility of a double-barreled cowbird scourge.
In Extinction, which they published in 1981, Paul and Anne Ehrlich compared a species’ extinction to the removal of a rivet from the structure of a very large spaceship on which one had no option but to stay on board, but which, unfortunately, was swarming with “rivet poppers”—identified not only as heads of state, business leaders, industrialists, the Army Corps of Engineers, the hierarchy of the Roman Catholic Church, and so forth, but also “you and us.” The Ehrlichs’ idea, of course, is that the entire structure of nature, as well as the quality of human life, is slowly being weakened. The Ehrlichs offered four arguments for keeping the rivet-removers at bay: 1) simple compassion; 2) aesthetics—“beauty, symbolic value, etc.”; 3) economic—direct benefits to mankind, which often are not immediately evident but can turn out to be enormous; and lastly, most important, 4) that mankind, in deliberately or unknowingly allowing a species to become extinct, is in effect attacking itself. The Ehrlichs pointed out that the ecosystem is an enormously complex maze in which every living thing potentially affects every other living thing, and thus the physical environment of the planet.
The authors give a telling example of this—a situation some years ago in Borneo when DDT was introduced in considerable quantities to eradicate mosquitoes; but the insecticide also knocked out predatory wasps, which kept down the numbers of caterpillars, whose favorite forage was the thatched roofs of native huts. The inhabitants were free of mosquitoes but their houses began to fall in on themselves. Moreover, spraying DDT to get rid of house flies started another chain reaction: the local gecko lizards that fed on the dead flies became sick and couldn’t avoid being taken by cats. The cats, ingesting huge doses of DDT, died, which led to a plague of rats. The government was eventually compelled to parachute cats into the area in an attempt to restore the natural balance.
Another, more local, example of the fragility of an ecosystem is suggested by what could well affect the northern migration of such shorebirds as knots, Ruddy Turnstones, Sanderlings, and Semipalmated East Coast Sandpipers—the most common shorebirds one is likely to see on the tidal mudflats from Maine to Maryland during the summer. In the spring these species congregate in spectacular numbers along a relatively small coastal stretch on the Delaware Bay to take advantage of the mass spawning of the horseshoe crab—a yearly event that occurs during the high-tides when the moon is full. The shorebirds feed on the freshly laid horseshoe crab eggs, produced in the billions by the female crabs in shallow depressions scraped out just above the hightide mark. While the horseshoe crab is common enough along the entire eastern coastline there are only a few spots where they come ashore to spawn.
To take advantage of this situation, perhaps 80 percent of the North Atlantic’s population of Red Knots assemble on a few miles of Delaware’s shoreline. The knots as well as the other shorebirds have reached a kind of migratory halfway station; they feed in a frenzy in order to continue, especially some species such as Sanderlings which are on their way to the Arctic Circle. All of this—as John Terborgh points out in Where Have All the Birds Gone?—is a wonderful spectacle for birdwatching, but a frightening one as well. An oil spill from tankers going in or out of Delaware Bay, or the development of summer “cottages” along the length of the shoreline would interrupt the horseshoe crab–shorebird eco-link. As Terborgh suggests: “migration is a chain whose strength is that of its weakest link.”
The concept of an entire eco-system being threatened has in recent years been somewhat overshadowed by intense efforts to save single species—the most obvious example being the Northern Spotted Owl, whose plight has become the subject of much derisive comment. During the recent campaign George Bush talked of environmentalists “knee deep in owls” while Dan Quayle mocked the activists for whom “owls are more important than people.” The issue should have been instead the fair use of the vast eco-system of the Pacific Northwest forests. The Spotted Owl is only one example of the flora and fauna that will be affected if the lumber companies have their way. Designating a single species as threatened or endangered can in fact lead to the exact opposite of what is intended: the residents of Texas’s Travis County, for example, fearing that development would be halted to protect the Golden-cheeked Warbler, began destroying the bird’s habitat of juniper trees. What the conservationists consider habitat, the developers think of as private property.
Environmentalists have been understandably relieved by the election of Bill Clinton and Al Gore. President Bush made it quite clear that if elected he would not sign a bill extending the Endangered Species Act unless a number of its provisions were changed. In fact, the election was inconclusive. There will now be fewer known supporters of the Endangered Species Act in Congress than during the Bush administration because many former supporters have retired, or were defeated in primaries; seven lost their seats in the election. A bill supporting the act introduced in the last session by Gerry Studds of Massachusetts had 107 co-sponsors, of whom thirty-one will not be returning. By contrast, a bill introduced last October by a representative from Louisiana, Billy Tauzin, which would have strangled the act with a large number of procedural requirements, had twenty-three co-sponsors, all but one of whom is returning.
A considerable source of worry for the environmentalists is the efforts of such powerful groups as the Endangered Species Roundtable, which includes representatives from the petroleum industry, the American Farm Bureau, mining and timber interests, the National Association of Manufacturers, and the US Chamber of Commerce. One of the roundtable’s primary aims is to narrow the scope of the act so that it no longer protects subspecies. This would in theory turn the entire habitat of the Northern Spotted Owl over to the lumber industry, since the Northern is one of three subspecies, the others being the California and the Mexican spotted owls, whose ranges stretch from southeastern Utah and central Colorado down through the mountains of Mexico. Alas, these two subspecies are also in serious difficulty.
The critics of the act would also like to exempt a species from protection if large numbers of it exist elsewhere. This could very well affect the Bald Eagle, which is common in Alaska, but far less so in the rest of the states, where, despite a strong recovery since the banning of DDT in 1972, it is still on the endangered list. The copper developers who want to open a mine within the Chilkat Bald Eagle Preserve in Wyoming would threaten the largest wintering population of Bald Eagles in the world.
Far more militant than the roundtable is a growing anti-environmental group called the Wise Use movement, a loosely-linked organization including, among others, loggers, fishermen, farmers, bikers, and snowmobilers, as well as Reverend Sun Myung Moon’s Unification Church. It refers to environmental associations like the Sierra Club as “whacked out Chicken Littles” and “faggots in the forest.” Among its goals as laid out in The Wise Use Agenda published in 1989, and reported in Audubon magazine’s September–October 1992 number, are to eliminate restrictions on wetlands development; to open all public lands—including national parks and wilderness areas—to mineral and energy production; to immediately develop petroleum in the Arctic National Wildlife Refuge; to rewrite the Endangered Species Act to remove protection for “nonadaptive” species like the California Condor; to allow the cutting of all decaying and oxygen-using forest growth on national forest land, replacing it with young trees to “reverse” global warming; to expand concessions in national parks to be run by private firms like the Walt Disney Company, which are expert in “people moving”; and to impose civil penalties on anyone who legally challenges “economic action or development on federal lands.”
One of the problems for environmentalists in opposing such pressure groups, is that some of their own programs will have difficulty in gaining public support. This is particularly the case with regard to policies toward developing countries. John Terborgh’s proposals are perhaps the most far-reaching. In his view, the way to save the tropical forests in the southern hemisphere is to get the people out of them: urbanization is the only hope for “taking pressure off the land and salvaging any remnant of tropical nature.”
This assumes that settlers trying to scratch out a living in Amazonia and other such places would flock to the cities if they were given incentives to do so. Terborgh points out that in Venezuela, because of its oil revenues, this has indeed happened: 75 percent of the population lives in the cities; the countryside is relatively intact.
“One way to slow down the destruction” of tropical forests, Terborgh writes in Where Have All the Birds Gone?
is simply not to build roads into regions that are inherently unsuited for long-term occupancy. Road construction proposals should be required to pass hardheaded cost-benefit analyses based on real, not phantom benefits…. New roads are an easy excuse for politicians who, unable to create legitimate jobs for thousands of unemployed heads of families, offer them bogus opportunities to “colonize the jungle.”
On a broader scale Terborgh suggests an increase in American spending on foreign aid aimed at reducing the rate of population growth, and that both in the US and abroad the government should stimulate urban industrial development, try to improve agricultural yields on fertile land, and initiate large-scale programs to cultivate forests on lands unsuitable for agriculture. There is much more in Terborgh’s book, even a warning about bird seed on the ground which leads to larger populations of starlings, Blue Jays, and, yes, the dreaded cowbird!
The authors of Birds in Jeopardy propose, on the whole, more traditional remedies. They list a number of well-known conservation groups committed to opposing “toxic influences of human society”—the National Audubon Society, the World Wildlife Fund, the Sierra Club, the Wilderness Society, and so on. They also list two organizations not usually associated with conservation activity, although they should be—the Washington-based organization called Zero Population Growth and the Sacramento, California, group called Californians for Population Stabilization. I would have added Planned Parenthood, the Population Crisis Committee (based in Washington, DC), the International Planned Parenthood Federation (in London), and the UN’s Population Council, which is largely involved in giving instruction on birth control in the developing countries. In the long run such efforts may do more to save the earth and its species than many others.
According to the latest projections from the United Nations Population Council, the world’s population, at its present rate of growth, is expected to double from 5.48 billion in mid-1992 to around 10 billion by 2050. A quarter of the earth’s arable surface has already been turned over to browsing cattle. It has been estimated (by Friends of the Earth) that every year the loss of tropical forest is roughly equivalent to the size of the state of Washington, a trend that, if it continues, would finish off the last acre of tropical forest in about fifty years—a catastrophe, not only for birdlife, but for much of the world’s biological diversity. One can understand the anxiety of the authors of Birds in Jeopardy to avoid a decline “into a world of hungry, discontented people whose avian companions are largely cowbirds, House Sparrows, European Starlings, Rock Doves, Common Crows, and Herring Gulls.”
Birds in Jeopardy includes a cautionary story by Jared Diamond, an expert on the eco-culture of the South Pacific, who describes the demise of the giant moas, the huge, slow-breeding, flightless birds that once populated New Zealand. When the Polynesian Maori people arrived there a thousand years ago, they wiped out the moas—the remains of over 100,000 have been discovered in the ruins of their ovens. “The Maoris,” as Diamond observes, “…had no annual Christmas bird counts, no tables of moa reproductive rates, and no books on previous extinction holocausts elsewhere. They can hardly be blamed for having precipitated extinctions. We, who exterminate today with full knowledge of what we are doing, have no such excuses.”
March 4, 1993
Subspecies have been defined as populations isolated from similar birds, usually by geographical differences of habitat, which would have a potential for interbreeding if there were the opportunity. ↩