In 1515, GonzaloFernàndez d'Oviedo y Valdés, a Spanish courtier bound for San Domingo,attempted to land on Bermuda, but was frustrated by a "contrariewinde." However, his sojourn was not misspent; while lying offshore hewitnessed an edifying spectacle.
"I saw astrife and combat betweene these flying fishes," he wrote, "and thefishes named giltheads, and the fowles called sea mewes, and cormorants, whichsurely seemed unto me a thing of as great pleasure and solace as could bedevised. While the giltheads swam on the brim of the water, and sometimeslifted their shoulders above the same, to raise the flying fishes out of thewater to drive them to flight, and to follow them swimming to the place wherethey fall, to take and eat them suddenly. Againe, on the other side, the seamewes and cormorants take many of these flying fishes, so that by this meansthey are neither safe in the aire, nor in the water. In the selfe same perilland danger do men live in this mortal life, wherein is no certaine securities,neither in high estate, nor in lowe."
The instructivefowl which Oviedo observed from the rail of his ship is now known as the cahow,or Bermuda petrel. In 1515 it probably numbered more than a million. Today itis one of the rarest birds in the world, only 65 or so being left, and Oviedo'smoral could be drawn with equal force and relevance from its unfortunatefate.
The survivingcahows breed on five greatly eroded islets with a total area of three acres,which lie about the mouth of Castle Harbour at the east end of Bermuda. Theyarrive clamorously in mid-October and the last dithering chick departs inmid-June. The cahow is thought to summer upon the vast reaches of the NorthAtlantic, but no one able to identify the bird has ever seen a cahow off thebreeding grounds.
Fossil remainsdating back at least half a million years indicate that the cahow is the oldestsurviving species of bird endemic to Bermuda, and when that uninhabited islandwas discovered by Juan Berm√∫dez in the first or second decade of the 16thcentury it was the most abundant bird as well: the remains of 30 cahows havebeen found in two cubic feet of talus, evidently victims of a cliff fall.Cahows make their nests at the ends of burrows which may be as long as 15 feetand have at least one turning so that light cannot penetrate—the birds arenocturnal and shun light on the breeding grounds.
Both the egg andflesh of the cahow are edible, and since it is in the habit of pottering abouton the ground at night and, moreover, is utterly fearless of man and othermammals (Bermuda, like almost all oceanic islands, has no native mammals savefor a few bats), it was virtually exterminated by 1630, presumably by droves ofhogs, which the Spanish customarily put ashore "for increase," and bythe English colonists who arrived in 1609.
The cahow wasgenerally considered extinct up to the present century, and it would, in fact,have died out by about 2000 A.D. but for the solicitude of a remarkable youngman named David Wingate. Wingate, who is 33, is Bermuda's conservation officer,the island's only resident ornithologist—of the 300 or so birds on the Bermudachecklist, more than 50 were first sighted by him—and the cahow's savior. Forthe past 10 years Wingate has devoted much of his life to keeping the cahowalive, spending innumerable sleepless nights in the field, but, as a friend hasreminded him, if you're going to play God you have to keep God's hours. Notonly is the cahow dependent upon Wingate; in a way Wingate is dependent uponthe cahow, for the bird has given his life an ennobling purpose. "I can'tafford to die," he said recently. "What would the cahows do?"
However, more isat stake here than the preservation of what the early English chroniclerscalled a "silly Bird." No sooner had Wingate laboriously built up thetiny colony than it was faced with a new and insidious threat: in recent yearsthe cahow has become contaminated with residues of DDT and, as a likely result,its reproduction rate has been declining. If the decline continues at itspresent rate, reproduction will fail completely by 1978 regardless of what athousand Wingates might achieve. The extirpation of this silly bird after itsastonishing survival would be exceedingly poignant, yet in itself hardlycalamitous to man. But Wingate correlates the cahow with the canary, whosedeath alerts miners to the presence of poisonous gases in the mine. Indeed, ifman persists in wantonly degrading his environment, he may well find himself in"the selfe same perill and danger."
The cahow is oneof about 75 species of petrels, all of which are pelagic, coming ashore only tobreed. (Petrel is probably derived from Peter; some petrels appear to walk onthe water, a feat attributed to the disciple.) The most familiar is Wilson'spetrel, or Mother Carey's chicken, a dainty little bird which is inclined tofollow ships far at sea and is reputedly the most populous sea bird in theworld. The cahow is roughly the size of a pigeon, but has a wingspread of 35inches. Its scientific name is Pterodroma cahow. Pterodroma is Greek for rapidwing, and cahow (which rhymes with allow) is a phonetic approximation of thecall the bird makes in its aerial courtship.
To a degree, thecahow's awful call note—most often heard on the dark and windy nights it favorsfor wooing—determined that England rather than Spain colonized Bermuda. TheSpanish believed that Bermuda was inhabited by demons and they avoided it. Oneof the earliest mentions of the cahow is by a fearful Spaniard, Captain DiegoRamirez, whose galleon was driven ashore by a storm in 1603:
"Theheadlands are undermined at water level with the haunts of nocturnal birds,which remain in their caves by day, but come out at night to feed on fish,especially on squid of which there are great numbers. These birds sallyforth...with such an outcry, and varying clamor, that one cannot help beingafraid, until one realizes the reason.... The first night that I anchored inthe bay, I sent a small boat to an inlet to look for water, but none was found.At dusk, such a shrieking and din filled the air that fear seized us. Only onevariety of bird makes this noise, but the concerted yell is terrible.... Oneseaman said to me: what is this devil trying to tell me? Out with it! Let'shear what it is! I replied: a la! These are the devils reported to be aboutBermuda. The sign of the cross at them! We are Christians!"
Another earlyaccount of the cahow was written by William Strachey, the secretary-elect forVirginia, who was bound there on the Sea Venture when she was wrecked in astorm off Bermuda in 1609:
"A kind ofwebbe-footed Fowle there is which in the darkest nights of November andDecember...would come forth, but not flye farre from home, and hovering in theayre, and over the Sea, made a strange hollow and harsh howling. They call itof the cry which it maketh, a cohow.... Our men found a prettie way to takethem, which was by standing on the Rockes or Sands by the Seaside, andhollowing, laughing, and making the strangest outcry that possibly they could;with the noyse whereof the Birds would come flocking to that place, and settleupon the very armes and head of him that so cried, and still creepe neerer andneerer, answering the noyse themselves; by which our men would weigh them withtheir hand, and which weighed heaviest they took for the best and let theothers alone...."
In 1615 Bermudasuffered a famine. To ease it, 150 of the 500 settlers were sent to Cooper'sIsland in Castle Harbour, now joined to the mainland and the site of severalU.S. installations, notably Kindley Air Force Base and an Apollo trackingstation, "ther to be relieved," Governor Nathaniel Butler wrote,"by the comeinge in of the sea-birds, especially the Cahowes...monstrouswas it to see, how greedily everything was swallowed downe; how incredible tospeake, how many dozen of thoes poore silly creatures...wer tumbled downe intotheir bottomlesse mawes: wherupon...followed a generall surfettinge, muchsicknesse, and many of their deaths."
A year or twolater Governor Daniel Tucker published a proclamation "against the spoyleand havock of the cahowes, and other birds, which already wer almost all ofthem killed and scared awaye very improvidently by fire, diggeinge, stoneinge,and all kinds of murtheringes." However, as Butler added, the edict was"overlate." A few years afterward the cahow was presumed extinct.
In the 1840s oneJ. L. Hurdis was assured by several natives that the cahow still existed, andhe made a rather feckless and unsuccessful attempt to obtain a specimen.Another 19th century figure, John Tavenier Bartram, fared better. Bartram was aretired soldier with "a meagre education and a liking for everythingnatural," who settled in Bermuda and was a fairly prosperous farmer beforehe began exhibiting "degenerative" tendencies: he rarely if ever wentto church, separated from his wife and, after she died, took a colored woman asa common-law wife and withdrew from society. Bartram's customary attire was along dressing gown, and the central portion of his long beard "wascarefully plaited in three and brought to a point." Bartram was intriguedby the cahow, and, like others before and since, he confused it with Audubon'sshearwater, or the pimlico, which it resembles. To complicate things further,he believed there was yet a third species, the Christmas bird; in fact, thiswas the true cahow.
"I have spenta good deal of time in striveing to clear up the mistrey hanging over thecahow, the christmafs bird...and the Pimlico," Bartram wrote in hisjournal, "but up to this day 2nd November 1862 all remains as much in thedark as it was before I commenced."
However, thatsame year, on one of the Castle Harbour islands, Bartram found "buried inthe sand, dead and pretty well dried up a bird not before known to breed onthose Islands. [This] bird was evidantly killed whilst sitting on its nest bythe falling in of sand and rocks from the top of the hole, was this bird astragler come here by acident, or do they breed here year after year, I havenever heard of them...." Unknown to Bartram, this specimen was a cahow andit, or conceivably another he obtained, was discovered by Wingate in 1953 in aHamilton antique store that had acquired the remainder of Bartram'scollection.
Despite Bartram'smuddled evidence to the contrary, the cahow was still regarded as extinct, orpersistently confused with the pimlico or the Manx shearwater. In 1902 A. E.Verrill went even farther astray. Not only did he avow that the cahow wasextinct, he believed it may have been related to the auks. One of Verrill'sarguments against the cahow's being a petrel was that it was edible. Of course,no one has eaten a cahow in more than 300 years, so it would be hard to say ifit would appeal to modern tastes. However, Wingate recently dined onblack-capped petrel, which breeds on Hispaniola and is the cahow's closestrelative. "There was nothing unpleasant about it," he reports, "butmy Haitian guide spiced the damn thing so much I couldn't tell what was thebird and what wasn't."
In 1906 a livecahow was collected on Castle Island by Louis L. Mowbray, but was identified asa Peale's petrel (Aestrelata gularis), a New Zealand species. In 1916 Mowbrayhad second thoughts, and he and John T. Nichols renamed the bird Aestrelatacahow. The same year R. W. Shufeldt appeared in print with a description of yetanother new species, whose relics he had found on Bermuda, and which he calledAestrelata vociferans, identifying it as the "extinct cahow." In 1922A. C. Bent hazarded that the Mowbray bird and the Shufeldt relic were of thesame species and wondered if "there may not be a few specimens stillliving." Astonishingly enough, no one attempted to find out.
In 1935 afledgling female, unmistakably a cahow, struck St. David's Light, close toCooper's Island, and was obtained by William Beebe, who was then living onNonsuch Island, where he had organized his bathysphere descent, but again nothorough search was made. The next specimen was collected in 1945 by Fred T.Hall, who found a badly mauled bird washed ashore on Cooper's Island. Finally,in 1951, an expedition headed by Robert Cushman Murphy and including the16-year-old Wingate discovered several nesting sites, one of which wasoccupied. "With a noose at the end of a pole we presently succeeded inhauling out the bird," Murphy wrote. "It was the hoped-for but onlyhalf-anticipated cahow.... Our exciting captive bit the hands that grasped it,but only briefly and halfheartedly. Within a moment it became completelynonresistant, allowing itself to be stroked, tickled and passed from hand tohand."
Murphy'sexpedition located seven nesting pairs on two islets. Since searches of thelarger and more accessible islets turned up only mingled rat and cahow bones,Murphy believed that rats were limiting the cahow population. For this reason,the first step toward protecting the bird was to eliminate the rats by trappingand poisoning them. (This didn't endanger the cahows, as seabirds never feed onland.) However, it soon became obvious that the rats had had little effect.Improbably, the real villain was the white-tailed tropic bird, or longtail, asit is called in Bermuda, a handsome seabird a little larger than a cahow, whichnests there in substantial numbers.
The diurnallongtail returning to breed in mid-March, shortly after the cahow chickshatched, entered the cahow burrows while the adults were feeding at sea andkicked and worried the helpless chicks to death. Thus, in 1951, all four knowncahow chicks were killed, their corpses found in a litter of bones representinggenerations of baby chicks. It appeared, therefore, that the only reason thecahow had survived at all was that it was nocturnal and the longtail diurnal,so they rarely met. By the time a pair of longtails was staying overnight toincubate their egg, the cahows, having lost their chick, would have abandonedthe burrow. Because cahows are longer-lived than longtails, they had a slightchance of rearing a chick if, for some reason, a pair of longtails didn'toccupy the nest in any one year.
Although thismight explain how the cahow survived the last 300-odd years, it doesn't accountfor its former abundance. The reason is that in prehistoric times the cahow andthe longtail bred in separate ecological niches, the cahow inland where itcould tunnel into soily hillsides, the longtail in natural holes and crevicesin rocky coastal cliffs. Although overlap occurred and thousands of cahowchicks perished in the marginal zones, the slaughter had a negligible effect onthe total population. However, by the time Bermuda was colonized the hogs hadeliminated the cahows from their natural habitat, and they were confined to theoffshore islands. Since virtually every island with soil cover has beeninhabited by man at one time or another in Bermuda's history, the cahow'sbreeding grounds have been reduced to the smallest and the least accessible anddesirable islets where there is insufficient soil for burrowing and where thecahow has come more and more into competition with the longtail. Man has longsince abandoned many of the preferable islands, but the cahow is semicolonial,has a strong homing instinct and stubbornly persists in returning to thehandful of rocky islets.
When thelongtail's role was understood, it was proposed that all the longtails whichfrequented the two islets should be shot, and a number of them were. But itsoon became apparent that the massacre of hundreds of long-tails for the sakeof a rather drab bird which was never seen was unjustifiable. So from 1952 to1955 three naturalists attempted to scare off any longtails which sought toenter cahow nests. This proved impracticable and the cahow chicks continued tobe killed.
In 1954 RichardThorsell, a graduate student, came up with an ingenious solution—a baffler.Taking advantage of the fact that the longtail is slightly larger than thecahow, Thorsell placed an artificial wooden or stone entranceway before eachcahow burrow, just big enough for a cahow to squeeze through but too small fora longtail.
The bafflernotwithstanding, the cahow population remained static until Wingate took overthe program upon graduation from Cornell in 1957. It was soon obvious to himthat the bafflers weren't working properly. The difference in size between thecahow and the longtail is minute and the bafflers hadn't been made to preciselythe right dimensions. In the spring of 1958 Wingate spent six weeks living in ahut on one of the islets, sleeping days and working nights, gradually reducingthe size of the holes in order to condition the cahows to enter ones which theyhad previously balked at.
A further problemnow arose: at times, no matter how small Wingate made the entranceway, alongtail would push itself through. Providentially, he soon discovered that thelongtails which could not be dissuaded were those which had previously nestedin that particular site; these Wingate has had to kill. Whenever a cahow pairnests in a burrow he knows to have been previously inhabited by longtails,Wingate goes out at dawn two weeks before the longtails are due back and plugsup the burrow, returning at sunset to unplug it. He follows this procedureuntil the presence of footprints in the sand outside the burrow tells him thatthe longtails have returned. The following morning he places the plug partwaydown the tunnel, waits a number of yards off, and when a longtail enters,reaches in, grabs it and drowns it. He has to repeat this procedure thefollowing morning because if he doesn't kill both birds, the survivor willremate and the new pair will attempt to enter the burrow. As a result, from1961 on no cahow chicks have succumbed to longtails.
In the long run,however, bafflers are impractical, principally because they have to be checkeddaily throughout the breeding season: a twig or pebble lodged in the entranceby a cahow can forestall entry. (One of Wingate's recurring dreams is thatcahows are nesting in a building on Nonsuch, but all the doors and windows areshut so the adults can't get in to feed the chicks.) But at times high seasmake it impossible to land on (or leave) the cahow islets, which have noharbors. Wingate was once marooned without food for three days when a stormarose.
Because chickmortality had been virtually 100% in the seven known nest sites up to 1958,Wingate suspected that there had to be a number of undiscovered burrows notsubject to longtail competition; otherwise the cahow simply couldn't havesurvived. By 1960 he had found 11 more nests on three additional islets. (Thereason they remained undiscovered was that the cahow's habits were not fullyknown; starting about December 1st the birds leave the breeding grounds for sixweeks, returning only at the moment the females are ready to lay, and the earlysearches had been made during this exodus period.) Fortunately, the rocks onthese islets are so riddled that the cahows, who seek their nests on foot, wereable to find holes that longtails, which search entirely on the wing, hadoverlooked. Even so, four of the newly found nests were subject to entry bylongtails.
In an attempt tosolve the baffler maintenance problem, Wingate decided to reverse the historicchain of events which forced the cahow to compete with the longtail. He builtartificial burrows near the crowns of the islets, where there is vegetation anda bit of soil, although not enough to enable the cahows to dig. The burrows arelined with cement, and the nest chambers have removable lids to facilitateobservation. To date Wingate has made 14 burrows, of which five are occupied.None has a baffler and none has been entered by longtails.
It was Wingate'sdream to build up the cahow population until a natural overflow was created,and the birds would move to neighboring islets more closely resembling theirancestral habitat—like Nonsuch, which he estimates could support 25,000 pairs.To hasten the emigration, he had planned to record their call and play it backon the slopes of Nonsuch. Then, as he somewhat facetiously proposed, theprogram could have been put on a paying basis by selling surplus cahows tohotels for gourmet dishes.
But although thebreeding population has gradually increased to its present level of 22 pairs,the pairs that have raised chicks have declined during the past decade frommore than 60% to 25%. In the beginning Wingate attributed this to senility andinbreeding, but the adults faithfully incubated the eggs and cared for thechicks, which would be unlikely with senile birds; even more significantly, nodeformed chicks were observed, and if senility or inbreeding were a factor itshould be declining with the burgeoning population, the formation of new,vigorous pairs and an expanding gene pool.
The dwindlingproduction of young may be due in part to a reduction in the percentage ofpairs laying an egg, but the primary cause is undoubtedly the failure of eggsto hatch. In particular, there has been a growing mortality of chick embryoseither in the egg or at hatching.
In 1966 thesephenomena had become so prevalent that they ranked in significance with theearlier mortality from longtails. The record of one breeding islet whichsupported six pairs in 1967 is typical: of five fertile eggs laid, no less thanthree failed to produce young. One chick died within a day after hatching andthe other two while pipping the egg. In general, this mortality has beenrandom, affecting different pairs in different years. However, a few of theoldest pairs with an earlier record of breeding success have failedconsistently since 1961.
Wingate wasprompted to examine the possibility of pesticide residues in the cahow by theextreme similarity of its plight to that of certain birds of prey, where thecorrelation between pesticide residues and reduced hatching success has beenconvincingly demonstrated.
At first glanceit seemed inconceivable that the cahows could have become contaminated withDDT. Pesticides are used on Bermuda, but the cahow islets have never beentreated, the birds spend most of their time underground and they feed far atsea. However, in recent years it has become evident that DDT is present in mostof the world's animals, including birds and seals whose entire lives are spentin the Antarctic. Man is not immune: for example, Americans average 11 partsper million (ppm) of DDT in their fatty tissue. An organism doesn't have to besprayed with DDT to become contaminated. DDT is dispersed over the globe bywind and water in much the same manner as radioactive debris. When DDT issprayed aerially only about half may reach the ground; the rest is dispersed inthe air, where it may circle the globe in a few weeks. Oceanic currentsdistribute it too. Because DDT has a low solubility in water and a highsolubility in fatty tissue, it becomes concentrated in marine organisms, whichalso act as carriers.
DDT residues arevery persistent chemicals, sometimes retaining their toxicity for decades. Dueto their solubility they accumulate in food chains and reach their highestconcentration in the final link. Some carnivorous birds carry residues at aconcentration more than a million times greater than their environment. In aLong Island marsh sprayed with DDT for 20 years for mosquito control, theplankton contained 0.04 ppm, small fish 0.25 to 1 ppm, larger fish nearly 2 ppmand cormorants and mergansers about 25 ppm.
The cahow is theterminal carnivore of a five-stage food chain consisting of phytoplankton,zooplankton, small fish and squid. As Wingate and Dr. Charles F. Wurster,assistant professor of biological sciences at the State University of New Yorkin Stony Brook, pointed out in a recent issue of Science, the cahow feedsexclusively in the open ocean and is therefore "an ideal environmentalmonitor for detection of insecticide contamination as a general oceanicpollutant, rather than contamination resulting directly from treatment of aspecific land area."
In March 1967Wurster analyzed two unhatched cahow eggs and three dead chicks and found DDTresidues averaging 6.4 ppm. Although this coincidence in itself does notestablish a causal relationship, there are convincing parallels to other birds.Ospreys normally produce 2.2 to 2.5 chicks per nest, but a Maryland colony withresidues of 3.0 ppm in its eggs yielded 1.1 young per nest, and a Connecticutcolony containing 5.1 ppm produced only 0.5 offspring. (This colony declinedfrom 200 pairs in 1938 to 12 pairs in 1965.) In Britain breeding success infive species of birds of prey with residues averaging 5.2 ppm in their eggs hasdeclined, while in five crow-like species, which are mainly herbivorous,residues averaged 0.9 ppm and reproduction has been unaffected. Moreover, inthe last decade peregrine falcons have ceased to breed in the eastern U.S. andthe bald eagle, whose eggs contain an average of 10.6 ppm, may suffer a similarfate.
In the cahow, aswell as in other birds, chick mortality is greatest just before or immediatelyafter hatching, a phenomenon that has been reproduced experimentally by feedingsublethal diets of DDT to bobwhites and pheasants. This probably occurs becausethe DDT residues in the mother are passed into the yolk. When the embryoabsorbs the yolk, the DDT enters its system, and the older it gets the morepoison it assimilates—thus the highest concentration occurs when the yolk isfully absorbed around the time of hatching.
DDT is a nervepoison. Its presence in the vicinity of a nerve causes hyperactivity, resultingin restlessness and eventually tremors and death. DDT also operates on at leastone other mechanism—it can cause the liver to break down sex hormones,including the female sex hormone estrogen, which in birds affects maternalbehavior as well as calcium metabolism. When this estrogen breakdown isinduced, brooding behavior may be changed, leading to abnormalities such as eggeating. Records kept since the 1890s show that eggshells have had a consistentthickness and weight through the years. However, beginning in the late 1940sand coincidental with the introduction of DDT, many species of carnivorousbirds have laid eggs with shells as much as 25% lighter than the norm. Theseare prone to breakage and loss of water, and apparently contribute to chickmortality.
The only realsolution to the DDT problem is discontinuing its use. There are alternativepesticides that are less persistent and just as effective. Better yet is theuse of procedures that control only the pest species population. DDT isn't apesticide—it is a biocide in that it will kill all animal life if present insufficient quantities. Ironically, the insects for which it is intended canafford the terrific mortality rate since they reproduce rapidly and throughnatural selection develop resistant strains that require ever-greater dosagesto kill.
No one knows howDDT will eventually affect life on earth. The cahow story, when correlated withother evidence, suggests it may be disastrous to carnivorous birds. Themortality of salmon and trout fry from DDT in Lake Michigan and Lake Georgecould soon be repeated in the ocean, if it isn't already happening. Pacifichake, mackerel and tuna have been found to contain 0.2 to 2.0 ppm, higherconcentrations than those in fish of many lakes with heavily treated farmlandin their watersheds. Organisms at the bottom of the food chain are alsosusceptible. Thirty-nine percent of a batch of brine shrimp were killed withinthree weeks by a concentration of one part per trillion—the equivalent of1/1,000th of a drop in a tank car lot. A few parts per billion in water candecrease photosynthesis in certain phytoplankton. These algae are theindispensable base of marine food chains and are responsible for more than halfthe world's photosynthesis. Says Wurster: "Interference with this processcould have profound worldwide biological implications."
Fortunatelymammals are better equipped than other vertebrates to break down and eliminateDDT, but Win-gate suggests that even in infinitesimal amounts it may be havinga subtle effect on man. "The long-range effects of hormonal imbalance maybe graver than we suspect," he said recently. "Human behavior could bealtered by DDT and, although it may seem farfetched, perhaps some of our socialproblems might be influenced by our contamination with DDT. After all, societyis a delicate thing and the slightest change may throw it out of balance. Whilewe don't have all the answers yet, we do know enough to stop using it now."Otherwise, as Governor Butler wrote, it may be "overlate."
Last June I spentfour nights reclining on a down mattress on one of the cahow islets in the hopeof seeing a chick depart. Wingate lay on a mattress beside me. These mattresseswe had lugged ashore and carried on our heads up the lee cliff and across thecrown of the islet. On the fourth night I remarked that in a better world thanthis one of us would be a girl. Wingate replied that he used to have the bestline in Bermuda during College Week: Would you like to see my cahows? "Ofcourse," he added, "then they found out I really wanted to watch thedamn birds."
David BalcombeWingate, the ruddy, strapping second son of a Scottish civil servant whoemigrated to Bermuda in 1924, has two ruling passions: birds and what he isfond of calling "primeval Bermuda." This was not always the case."Originally, I was curious about bugs and spiders," he said one nightduring our vigil on the islet. "Then I went through a period ofegg-collecting. Between 10 and 12 I had an enormous phase in astronomy, whichwas replaced by an overriding interest in birds. I knew all the wood warblersbefore I was 12. It was worth your life to be considered a bird watcher as ateen-ager. It was not until I got to Cornell that I found there were others inthe world as oddball as myself."
There is nothingWingate would rather do than sit in his Boston Whaler at evening, on the edgeof the deep, and watch shearwaters veering past, migrating from Tristan daCunha to the Newfoundland Banks—it is a spectacle that greatly moves him. Hehas, however, contempt for the variety of bird watchers known as dickeybirders."They're the most irritating creatures on earth," he said. "They'veno ecological understanding. With them it's just like collecting stamps. I usedto take dickeybirders out to see the cahows. Once they saw one they couldn'twait to get back to the hotel. Their sole enjoyment was in seeing a birdsomeone else hadn't. In fact, having seen it they'd much prefer it if the cahowbecame extinct.
"Everycreature I've seen I regard as an individual and a character, and in each I'veseen something of myself and therefore gained a better understanding of myself.For example, the cahows have taught me a little bit about the function ofmarried life, the intimacy of the pair bond, the parents' faithfulness to thechick. This is being very anthropomorphic, but since all life springs from acommon ancestor, I believe anthropomorphism is justifiable. Oftentimes I'velain out on this cold, barren rock, a bit sex-starved myself, and been jealousof them snug in the nest. Silly little things! They seem to have such adetermination to survive! I can't picture a cahow saying, 'I'm determined tosurvive, I'm determined to survive,' but it's there instinctually. This appliesequally to man. As much as man consciously appreciates and argues his missionin life, so much of this is decided by instinct. It begins to make you realizethat you're part of the animal kingdom. How similar the cahows are to us! Ourroots link us irrevocably with the rest of the kingdom. Man must live inbalance with it. He cannot shake himself loose from it. It controls hisdestiny. All observations force this impression on me. We must retain ahumility toward nature.
"I feel thatI am morally right in trying to save the cahow, but it is a duty—not a penance.Although man is guilty of destroying the cahow he shouldn't blame himself forit. If I were an early colonist I'd have done the same. The birds walked intotheir huts at night, even right into the hearth fires. No wonder they thoughtthey were gifts from God! Modern man is arrogant, he has a blatant assumptionthat he can control nature, his own destiny, turn everything to his ownadvantage. He doesn't see the locomotive roaring up behind him which will smashhim to smithereens. Consider the land crabs. They're a bit of a pain in theneck. They spoil my lawn, girdle my trees. People say, 'That's no problem, it'seasy to get rid of them.' Sure, it's easy, but by destroying land crabs how amI throwing everything else out of balance? That's why I admit I'm defeated byland crabs.
"I havetremendous pride in Bermuda's heritage, which has been largely shattered.There's a grave danger if we destroy too much of our heritage we'll loseperspective on where we're going. Then we'll be like hippies—very insecurepeople. We've got to have roots in the past, I think."
In fact, Wingatefeels so strongly about primeval Bermuda that until recently he wouldn't permithis family to keep naturalized animals such as dogs and cats as pets. "Wehad pet skinks instead," he said. The skink (Eumeces longirostris) isBermuda's only endemic terrestrial reptile. "Skinks make rather goodpets," Wingate said. "When you're eating lunch, they'll come up andbite your toe and ask, 'Where's my lunch?' And if you start feeding themtunafish and hamburger, they'll scorn bread crumbs." However, one fatefulday a stray cat turned up at the Wingates, and the children, Janet, 7, andKaren, 5, wouldn't give it up. "There's something about a cat thatsatisfies a child's need that a skink doesn't," Wingate admitted. "ButI have one piece of pride left. I won't let the cat on Nonsuch."
Nonsuch, thelargest of the Castle Harbour group, is where the Wingates summer and is thesite of what he terms the Living Museum. Wingate is trying to re-create theprimeval environment on Nonsuch by reintroducing the original native plants andanimals that have been extirpated, and by eliminating the naturalized plants,mice, lizards, toads, whistling frogs, etc. In the past six years he hasplanted 4,000 trees, all in their proper niches and properly mixed and spaced.Among Wingate's plantings are a number of yellowwoods, which, rather like thecahow, were presumed to have vanished from Bermuda, having been heavily loggedin the 17th century. However, 15 specimens endure on a remote hillside. Wingateplanted a yellowwood seedling in Nonsuch's tiny cemetery. "I'd like to beburied under one," he says. "It's a great honor to be contributing tothe growth of the yellowwood. Anybody can be good for something."
On the firstnight of our watch on the cahow islet it was clear and the moon rose early sothe chick we were observing only got as far as the mouth of his burrow. Thenext night he emerged before moonrise, walked about exercising his wingsperiodically and was once briefly airborne. The sensation seemed to unsettlehim and he folded his wings and sat looking out to sea as though moonstruck.This, Wingate explained, is a characteristic quiescent period when the birdostensibly studies the stars and, as it were, sets his chronometer. "This,of course, is sheer speculation," he added. After a bit the bird went backin his hole. "Chicken," Wingate muttered.
On the thirdnight the wind was in excess of 20 mph and Wingate predicted that the chickwould not dare take off; indeed, he spent the greater part of two hourswandering uncertainly around trying to find a lee area where he could exercisewithout being buffeted, wildly flapping his wings so a gust wouldn't carry himoff. As is the case with all cahow chicks, he faced inland whileexercising.
On the fourthnight Wingate began to fret when the chick hadn't appeared on schedule. "Ifhe doesn't go tonight," he said, "I'm going to put an alarm clock inhis burrow." Next Wingate was worried that the chick had left before we gotthere; he had been delayed at a dinner party and it was already dark by thetime we arrived at the islet. "I'll give him until 10:15," he said."If he hasn't come out by then, I'm going to see if he's still there."The burrow we had under observation was one Wingate had dug, what he calls his"government housing," and when the deadline passed, he got up, removedseveral flat stones which camouflaged the lid, picked it up and shone hisflashlight in the nest chamber. The chick stirred. "It's just Wingate,"he said softly. "Go back to sleep."
"They sleepvery soundly," he explained, returning to his mattress. "I don't imposemyself on their life history. I try not to touch them. I just hover over themin case they need help, like a fairy godmother or a mother with a teen-agedaughter. I protect them from circumstantial fate. I have a feeling that theyknow it now."
We lay on agradual slope on the windward side of the islet, which was covered with nativeplants—sea lavender, coast sophora, scurvy grass, seaside purslane. Nearby, thecliff dropped 25 feet to the ocean, where the surf dully boomed, its spraywetting us. The only other sound was the faint chirping of the native cricket.It was a curious setting: except for being further eroded by land crabs, windand water, the islet was exactly as it was in the 17th century, yet only a mileoff was the Apollo tracking station, its great dish antennas, transmitters andreceivers brightly lit. Occasionally the headlights of a car pulling up at thetransmitters would nearly blind us. Too, planes and helicopters would from timeto time pass overhead or suddenly a series of flares would slowly descend tothe ocean for a practice capsule recovery.
All five cahowislets are bird sanctuaries and no one is permitted ashore except in Wingate'scompany. Oddly enough, three of the islets are under U.S. jurisdiction, and theSecretary of the Air Force has declared them off limits. However, it wasnecessary to erect masts on the islets as reference points to determine whetherthe radar dishes are settling on their foundations. The original design calledfor thin poles supported by guy wires. Since the wires would have been nearlyinvisible at night and therefore hazardous to the cahows, Wingate negotiated,as he has rather grandly said, "with Goliath on behalf of the cahows."The masts were redesigned and are now made of thick pipe painted white. Wingatewas also assured that the masts wouldn't be erected in his absence. Fortunatelyhe had the presence of mind to stick close to the workmen when they werelooking for likely sites. On one islet they found a good spot, a natural cavityformed by two cahow burrows. If Wingate hadn't been on hand 8% of the world'sbreeding population would have been sealed in cement. Wingate helped findanother location, but he still didn't trust the workmen. "I had to sit downand watch them dig this bloody, four-foot-square hole," he said. On anotheroccasion some boys lit a campfire in a cave containing two cahows. "If Ihadn't spotted it the embers could have burned the cahows' feet thatnight," Wingate said. "It was a real shocker. I contacted the AP's andthey tightened up security."
Wingate tries toobserve the departure of each cahow chick. "It gives me a feeling ofsuccess," he said. "Another year got through." On the average, achick spends seven nights exercising before he takes off; his parents have longsince left so he has nothing to eat during that period. The final night ashoreis usually distinguished by violent preening and intention movements in whichhe vigorously bobs his head in the direction of the sea. The chick generallyseeks a prominence from which to take off, and when he finally goes, he shootsstraight up like a helicopter. One reason may be that he doesn't know hisflying capacity and is overdoing it. Another may be that rapidly gainedaltitude is a safety factor; when the cahow lived inland a chick would have toget up about 40 feet to clear the cedar forest.
"There arehesitant chicks and cocksure chicks," Wingate said. The first chick he everobserved was by far the most irresolute. "He had been without food fornearly a month," Wingate said. "I stayed up four full nights, hidingunder a blanket. I didn't know they normally only come out once a night or thatit was unnecessary to conceal myself. The fourth night it was obvious that thechick was starving. He was desperate. Finally, he shrugged his shoulders,jumped off the cliff and fell 35 feet into the sea. I went and got my boat andpaddled it around. The chick was bobbing on the surface, drinking a lot ofwater and preening; it must have been dehydrated. He paddled in circles andthen did the instinctive thing and headed seaward. As he approached the outersurf line you could hear the thunder and there was a lot of phosphorescence.There was only one way through the reef, but I figured he knew the right thingto do and would find the opening, which he did without hesitation, and Ipaddled after him. He was now out in the deeper ocean. The swells would castshadows and I'd lose him. I was so tired I kept dozing off. Finally there wasan extra deep swell and he just vanished. He may have taken off. He may havebeen swallowed by a shark. He had swum two and a half miles in two hours. Itwas probably a good thing he disappeared. Otherwise, I'd still be followinghim."
On severaloccasions Wingate has felt obliged to do more than hover. "In 1962 a chickfell 25 feet down the cliff and forgot all about flying," he said. "Hetried to climb back up all night long. He would get up to 12 feet and then falldown again. Finally, at dawn, he became agitated and began looking for a placeto hide. I picked him up and took him home to Nonsuch and put him in a dresserdrawer, where he slept all day. If the crows had found him they would havepecked his eyes out. The next day I made an artificial burrow for him—a boxwith a hole. I could have put him back in his burrow, but I used the incidentas an excuse to take him to Nonsuch, where it was more convenient to watch himdepart and to which he might even return. He came out to exercise at the normaltime with the same old indecision, then went back in the box. By the thirdnight I was fed up. I picked him up and put him on my hand, moved it up anddown very slowly and then suddenly let it drop so that he found himself hangingin midair. He shot up to 100 feet and flew off to sea.
"This year Ihad a chick living on an islet where there's a good deal of prickly pear. Icleared a lot of the cactus off and laid an old sleeping bag down as a take-offramp. One night the chick pottered awkwardly off in a new direction, so Ithought I better have a look at him. One of his eyes was closed and it appearedto me that it had been punctured by a prickly pear spine. I stuffed him in abrown paper bag, took him home and put him in the dresser drawer. He made sucha fuss, I had to let him out. He walked around the floor all night and Icouldn't sleep. Pitter, patter, pitter, patter. He even tried to climb theskirting board. It was no use sleeping, so at 5 a.m. I took him out on theocean. He flew into the water, splashed around, drank, preened; he wasdelighted. His eye was fine—he had probably just got a bit of dirt in it. WhenI restarted the engine, he leapt out of the water, flew up to 100 feet andheaded away to the southeast.
"Up tonow," Wingate said, "I thought the cahow, in its glorious isolation,had a better chance than anything to survive. It is as if the natural habitatof the whooping crane had been Central Park. The cahow requires so very littleland; it's not asking much—a few rocks man has no need for. And it is as safeon the ocean as any creature, while the crane must traverse a perilouscontinent. There's a lot in the cahow's favor. Chances of finding it on theocean are infinitesimal. The islets are secure, the longtail problem is licked.Even if a person came to look for a cahow he probably wouldn't find one. And itall has been done through the efforts of one individual. There was no need tomake it a luxury project with a big staff; money's needed more vitallyelsewhere. Of course, there ought to be a standby if I fall over a cliff or getswept out to sea or if my wife Anita and I want to go on holiday. I had anoffer to go to the Bahamas and work with millions of seabirds. How could Ileave the cahows?
"Then itsuddenly changed from a situation where further effort was irrelevant to onewhere an international agreement is necessary. A farmer spraying crops inNebraska is involved in the cahow's survival. Now my only hope is that thetragic plight of this rare bird will have some propaganda effect, that it willmake man fully aware of the extreme gravity of the problem: if he can save thecahow, he can save himself."
As if on cue, ourchick emerged from his burrow and could be dimly seen poking around in thedark. When he exercised there were flashes of white from the underwings. Hewalked onto Wingate's mattress and nibbled on his fingers. Then he went over tosit by some sea lavender. The night had become overcast and the rising moon andthe lights from the tracking station illuminated the cloud cover so that itformed a light backdrop against which the cahow was silhouetted. Suddenly heleft. With a great noisy beating of his wings, he rose vertically. At about 40feet he was blown inland by the wind. Then he regained control, leveled off anddisappeared to sea.
He almostcertainly will not return to land for at least two years and probably will notalight for three or four. Two Februaries hence he will come back and hangaround for about a month, mingling with the flock in the air. Perhaps thefollowing October he will seek a nest site, and the year after that he willmate, vociferously chasing his partner in paired flight.
How extraordinaryit is that the cahow can find its way home! Bermuda is a speck in a nearlyfeatureless ocean. The winds thereabouts are changeable. The October heavensare different from those of June. Although certain migratory birds undeniablymake far longer flights, they are guided by landmarks of one sort oranother.
"He was avery calm chick," Wingate said meditatively. "Unruffled. He was aconfident bird." We heaved the mattresses onto our heads and plodded acrossthe islet. "You know," Wingate added after a bit, "I once had avision of the future. The islets were gone, eroded away by geologicalprocesses, but the cahows still returned, nesting in artificial burrowsfastened to pipes that someone had stuck in the ocean."
The cahow makes its nest on islets such as this off Bermuda.
The nest of a man-made cahow burrow has a removable lid.
A cahow exercises by burrow equipped with wooden baffler.