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Vk NATURAL HISTORY MAGAZIN November, 1971 The discovery of birth dc* fortuities among Inc terns on Great Gull Island was due largely to the efforts of Helen Havs. Aided by crews of volunteers from The f American Museum, she has l>een studying the colony in Long Island Sound since lp66. Chairman of (he Croat Gull Island Committee of the Museum's Department of Ornithol* ogy. Ilnvs has also studied ruddy ducks in Manitoba. Canada; ibises and herons in Jamaica Bav. New York: and terns in North Carolina. She holds a B.A. in conservation from Wcllealey College and au thored "The Adaptive Ibis" in the IF YOU DON'T KNOW what charcoal mellowing does for Jack Daniel's, we'd suggest a talk with Herb Fanning. Herb was the Jack Daniel purchasing agent for thirty years. So you can be sure he knows his whiskey. And he'll tell you there's no better way to make it than with charcoal mellowing, the ancient method Jack Daniel invented a century ago. After a chat with Mr. Fanning, you'll agree he's a pretty good convincer. But then, CHARCOAL MELLOWED 6 DROP 6 BY DROP so is a sip of Jack Daniel's. MGNS 069891 TENNESSEE WHISKEY . 90 MOOT 8Y CHOICE Ittl, IkI OiaM MtMWfv. l*a DISTILLED Alio SOTTICO SY JACK DANIEL DISTILLERY LYttCNIUftS (POPISH). T(NN. The ultimate African adventure. Spend an unforgettable 39 days luxuriously touring from Capetown into the heart of breath taking East Africa. Your group, limited to 25, will tour In special air-conditioned fivepassenger vehicles with a window seat for each member. You'll enjoy personal care and attention. The limited membership also will allow for such pleasures asa la carte dining, special events and visits to private homes and small villages. You will travel through South Africa, Rhodesia, Kenya. Tanzania, Uganda. Stay at luxury hotels like the world-famous Treetops, the Mt. Kenya Safari Club and the new Paraa Safari Lodge, overlooking the Nile. But best of all, you will experience the incomparable physical beauty of Africa. Such _ spectacles as the breathtaking beauty of Victoria Falls.The Ngorongoro crater. The majesty of Mt. Kilimanjaro, and the incredible variety of wildlife: gazelle, zebra, wildebeest, rhino, lion, and elephant But this small advertisement can't do justice to the sights and sounds of 39 magnificent days of beauty, wildlife, deluxe accommoda- * tions and transportation. There are 14 departures, in all, only 350 people will be able to take this ultimate journey. Be one of them. Send for our free brochure. August-Scptembcr, 1967, issue of Natural History Magazine. Coauthor and investigator with Hays of the developing Great Gull Island tragedy. Robert W. Riaebroughjs an associate research -"ecologist with the Bodega Marine laboratory of the University of Cal ifornia. He has conducted field work in the Indian Ocean, South east Asia, Latin America, the Gala pagos, Antarctica, and the Cana dian Arctic. Riscbrough, a native Canadian, has a Ph.D. in molecular biology from Harvard University. He plans continued research on the efTects of pollutants upon birds and marine ecosystems, including the terns in Long Island Sound. A more detailed report on the deformities discussed by Mays and Risebrough will appear in a forthcoming issue of The Auk, William A. Dunson, associate professor of biology at Pennsylvania State University, nas done much of his work on sea snakes aboard the Alpha Helix, research vessel of the Scripps Institution of Ocean ography. His investigations have concerned the successful adapts* tions of snakes to a marine environ ment and the reasons that other reptiles are not as numerous in the sea. He is planning a sabbatical next year during which he will study the physiological ecology of sea snakes at the Australian' In stitute of Marine Science. Dunson earned his Ph.D. in zoology at the University of Michigan. Charles G. Adelsen, author of 'The Road to Ani," has teamed with photographer Henry AngeloCaslriUon for eleven vears lo re port on eastern Turkey in European media. This article is the result of their second trip to Ani in seven vears, during which thev found travel restrictions eased and mili tary commanders far more relaxed about tourists. Ani is still not easv to get to, though, they add. Belgian Iv'orld Airlines. {"~ Sabcna BelgianWorld Airlines NH I 720 Filth Avcnua Ncw'ferX.N.Y. 10019 Please send me Information on the I Sabcna Cape to Kampala tour. Nms___________ - , Address--------------------------------------------------- CityStataZip-------- My travel ifenl Is_____ ,J HONS 06989i TIhi fan% WsurflMg i? ftOu Tetnnis Thousands of terns have replaced the Army on an island fortress originally designed to detect an enemy invasion of New York. The enemy has now arrived, and a major ornithological disaster may be upon us by Helen Hays and Robert W. Risebrough Great Gull Island is a small, un inhabited pile of rocks, clay, and shifting sands at the entrance of Long Island Sound lictwccn the eastern tip of Long Island and Con* nccticut. Because of its strategic lo cation, for half a century the island served as part of the defense system of the nation; today, the striking in crease of birth-deformed birds mere may be a warning of a new and moro insidious danger. The island is an excellent habitat for terns, small members of the gull family that nest on isolated coasts and barrier beaches throughout the world. To survive in these tem pestuous areas of winds, tides, and shifting sands, the terns have to be adaptive and sensitive to change: always shifting, colonising newly formed habitats, or quickly desert ing old ones as they are destroyed by the elements or by man. Nearly a century ago, when the rapacious millinery trade in its pur suit of feathers for fashion threat ened the survival of terns on the East Coast, conservationists pro vided a warden on Crest Cull Is land to save the birds. The 14,000 terns on the island became the last nesting colonv, the last hope for terns in the New York region, as other colonies on Long Island Sound were wiped out by plume hunters and eggers. Shortly after 1900, terns became a protected species when a pioneer ing piece of conservation legislation was passed in the United States. But, ironically, the legislation came too late for the terns on Great Gull Island, for in 1897, on the eve of the Spanish-Amcrican War, fearing attack by a Spanish armada, the United States government had be gun the construction of Fort Michie on die island. With the arrival of the military, the terna disappeared. On the following decades, the shadow of war rarely lifted from Great Gull Island. During World Wars I and II, the military used the island for its continental warning and defense system. From tall ob servation towers, soldiers scanned the ocean, nlwavs alert to the dan- f;er of attack. Over the years, the ort became a complex maze of gun emplacements, ammunition depots, barracks, and towers. Bv the end of World War 11. the island was al most completely covered with con crete and asphalt. And the terns avoided this unnatural transforma tion of their former habitat. Then, in the late 1040's, Fort Mlchic lost its function in * the warning and defense system for the continent. It became a symbol of obsolete military equipment and strategy, and in 1949 the Army abandoned the island, leaving be hind its concrete and asphalt, junkpilcs, man-made hills, and a necklace of traprock boulders placed around the island to stabilize its shores. Although man was gone, the habitat was too disturbed for the terns to return. Yet by the late 1910*s, the terns of Long Island badly needed a new breeding area; the old protective legislation was no longer adequate to save them from new devel opments. The encroachment of fac tories and housing developments in coastal areas, along with the con version of beaches to public parks, drastically reduced the number of undisturbed nesting areas for terns in the New York region. Aware of the island's history. Hie American Museum of Natural History and the Linnaean Society of New York worked to acquire Great Gull Island, hoping that it might again become a large colony for nesting terns. In 1949, the Museum received title and assigned to the Linnaean Society the task of return ing it to a condition suitable for terns. In 1949 and 1950. several of the buildings were leveled, vegetation was burned, and sand was deposited in an effort to create artificial beaches. Each year the island was visited by ornithologists from the Linnaean Society and the Museum, but it was not until 1955, after ev eryone had given up hope that the HONS 069893 J9 '> birds would ever breed there again, that twenty-five pairs of common terns were found nesting. The birds had not utilized any of the areas prepared for them, but had laid their eggs on the traprock at the eastern edge of the island. The numbers of terns increased each succeeding year and today, once gain, the island is the site of one of the largest colonics in Long Island Sound, comprising about 7,000 birds. Wv hen people now land on the island in late spring or early sum mer, the terns swirl noisily from the ruins of the fort, challenging the in truders and diving at them should they approach the nest sites. Re minders of the island's occupation by the military still remain every where. Iltc ruins of the aiinmloncd fort, overgrown with vegetation, stretch from one end of the island to the other. Ilic battlements are manned, however, by new defend ers. On patches of exfoliating con crete in the gun emplacements and in the open areas that were once building foundations, common terns incubate their eggs and feed and brood their young. The roseate terns, less aggressive than the com mons, deposit their eggs in the grassy edges of the open areas or under boulders on the outer beaches. Their utilization of the ruins of the old fort on Creat Cull Island demonstrates the tern's remarkable adaptability and use of habitat, a previously unknown characteristic of the species. A number of other species also occupy parts of the ruins. Barn swallows dart in and out of the weathered buildings, patching them with mud for their nests, Bnyberry and wild rose, as well as several species of grasses, have invaded the ruins, making them habitable for nesting rcowinged blackbirds, song sparrows, and spotted sandpipers. Starlings also nest in the eaves of building?. By 1966, the colony appeared sufficiently large and stable to per mit ornithologists from the Museum to undertake studies of the breeding biology of both species of terns, as well as of several of the other spe cies nesting on the island. During trie summers of 1967 and 196B, however, there was a great deal of rain and a scarcity of fish. Chemical pollutants, such as PCB's, are highly suspect as the cause of an alarming increase in gross birth deformities among the terns on Great Gull Island. This four-legged common tern chick died three days after hatching. / 40 MCNS 069895 Still straining to fly after fourteen weeks, the abnormal common tern, right, can only manage to rise a few feet. It had the double misfortune of being born without secondary flight feathers in a nest built within the insurmountable rim of a huge gun emplacement. It is doomed in this concrete enclosure. The fate of the five-week* old chick, far right, is similarly sealed: it was born without tail feathers, primary, and secondary flight feathers. Fort Michie's ruins, below, still dominate the landscape. MOMS 069896 Mil *" ' ' 11U144 . !l -.- r^- - ' w .*#.-.-*^5 -t^: 1 il ' I --"vj >1^.^. . V ^WSRSiSB* . <$.'*, l< V .til v< >u.:'*,. ;:$& -.,: ' aw ;:-n. jAi., J',r*j?yv7',',, ''' Many young terns died from ex posure, starvation, or both. A major Erohlrm in the field of population iology is determining the produc tivity of a species under a variety of environmental conditions, favorable and unfavorable. The colony on Great Gull Island appeared to be an appropriate site to study this prob lem in relation to terns because the island's sixe, seventeen acres, was mall enough to permit a daily checking of all nesting areas. Daily coverage of the nesting grounds permitted large numbers of young terns to he marked at hatch and marked with lempnrary plastic hands. Of these, one young com mon tern was found with an abnor mal bill and an upper mandible crossed over its lower. Then, two S roseate terns were found, appeared normal, hut which were missing flight feathers in both wings. We noted these deformities, but the flight feathers of the rose* ates appeared to be growing again. In a sample as large as 2,000 indi viduals, a few abnormalities are to be expected, and we did not attach special significance to these. ing, (hen followed with relative case up to the time of fledging and de parture from the colony. Studies of survival and mortality of both spe cies of terns were begun in 1969. The number of field workers in creased each weekend with the arri val of volunteers from the Museum. To avoid exposing the eggs and the young terns to the midday sun, all work in the colony was carried out whenever temperatures were favor able, usually in the early morning nr late afternoon. The terns in variably put up a vigorous defense. Working in a tern colonv is strictly a "hard hat" job, since the terns do not hesitate to strike unsuspecting al n 1970, however, when the study was repealed, we noted a sharp in crease in the number of abnor malities. Four voung roseate terns and thirty-three young common terns were found with visible de fects. Some of these appeared nor mal at the lime of hatching, but later, when they were between two heads with formidable force ana and four weeks old, lost thrir pri very sharp beaks. Usually several mary and secondary flight feathers. workers would traverse an area to gether, looking for new nests and young birds. At hatching in 1969, more than 2,000 young terns were examined Feather loss is a new phenome non that has not been previously described, although in the past many thousands of terns have been banded in Massachusetts, the Carih- ' < MONS 069897 43 Crowed mandibles were discovered in the colony in 1969, the first full year of the research project. This roseate tern chick, from the 1970 breeding season, was collected when three weeks old for chemical analysts of its tissues. bean, and on islands in the Pacific. Although these birds appeared to be healthy and vigorous, they could not fly. Two livqd as long as six weeks. Many disappeared, however, so complete observations of their mortality rate were not possible. Ita feather Ion did not seem to be necessarily permanent, as one of Utc young common terns found with no primary and secondary _ liners was seen Hying a month Inter at Milford. Con* ncclicul, about (10 miles away. Other abnormalities were com* parable to those observed in human 'thalidomide babies." One chick had underdeveloped legs and feet / with almost no down, and another had four legs. Several showed ab* normalities in- the development of the hill. One chick had extremely ' small eyes. H was at this timo that the au thors combined forces and ex* pericitce in an attempt to determine the causes of the abnormalities. Our suspicious centered on environmen tal pollutants in Long Island Sound, the Hush for much of the effluvia of New York and Connecticut. An in vestigation of this type, however, encompasses many different dis ciplines, and only detailed studies, over period of time, will tell us what is actually happening to the population structure and reproduc tive capacity of the sttccics affected by pollutants. In order to identify the pollutants that might be respon* " sible for the abnormalities observed in the field, complex research In the chemistry laboratory is also neces sary. The studies during the present year, therefore, were carried out with the realization that we were dealing with a new kind of enemy force, far different from the ravages of the plume hunters or the destruc tion of breeding sites. This enemy foreshadowed grave consequences for the future of the terns and quite possibly for man himself. There was no doubt that we were looking at the tip of a potentially disastrous iceberg. Hiis year's incidence of gross de fects among newly hatched chicks was approximately rompuruble to that in 1970. The first to lie found had an abnormal foot and leg. The second had a rudimentary upper mandible, which had grown out from above its eyes. The third ap peared as if injected with air or wa ter; its skin was swollen about the head, neck, and abdomen. The fourth had no left eye and a slightly crossed bill. Three others had bald spots on their bodies where feathers had not developed. The loss of (light feathers was again observed in many of the chicks. These arc the kinds of effects that might be expected from a chemical capable of affecting gene reproduction dur ing embryonic ceil division. Added to this, in 1971 a new ab normality was observed in the col ony for the first time: thin-sheiled eggs not sufficiently strong to sup port the weight of the incubating parent. This phenomenon is now fa miliar to pollution biologists, hav ing been first reported in British peregrine falcons in the 1950s. The brown pelicans in California have not bred successfully for a number of years because of this problem, and some of the birds of prey in this country are suffering serious population declines for the same reason. Researchers in this area believe that shell-thinning is caused primar ily by the DDT compound, DDE. Inis pollutant, a derivative of the insecticide, is only slightly poi sonous to most individual organ isms, but it may produce such ef fects as shell-thinning, which lowers the reproductive capacity of the species. DDE has been shown to < HONS produce shell-thinning under ex perimental conditions in mallard ducks, Amcriran kestrels, quails and doves. Wild species that are suffering from the thin eggshell svndromc have also been found to he contaminated with DDE. The DDT levels we measured in the abnormal young terns on Great Gull Island and in the fish brought to the colony by the adults in 1970, however, were no higher than in many other bird populations. In fact, they were lower than some. While wc have no basis for believ ing that any of the DDT compounds are responsible for the observed de formities in the voung terns, we cannot rule it out as a possible cause of shell-thinning. This was not observed until 1971, and we have not yet measured DDT levels in the 1971 specimens. Levels of other heavy metals, such as lead and cadmium, are cur rently being measured, but until much more data from other popu lations are accumulated, we shall not know what the expected natural levels of these elements in tern eggs should be, or bow to interpret the concentrations found. w. f hat we did find were rela tively high levels of polychlorinated biphenyls, PCB's. in the tern tissues and in the fish upon which the birds feed. These compounds have a number of chemical properties similiar to DDT. Like DDT and its de rivatives, thev become concentrated in the fatty tissues of animals when present in a food chain, but thev are even more stable. Used exten sively as hcal-exchange and in sulating fluids in high-voltage elec trical equipment, I'CB's are also added to paints, plastics, and rub ber to make these materials more resistant to breakdown. This prop erty of resistance to most kinds of biological and chemical degrada tion, which has made them so use- 069898 45 fut to industry, ire whit mike PCB`* such persistent pollutants when released in the environment. Interestingly, in some of the studies in which PCB's were fed to birds in order to determine toxic effects, the birds lost feathers. The PCB's may well, therefore, be responsible for the feather loss observed in the voung terns on Great Gull Island. Recent research conducted in the Netherlands has demonstrated that PCD preparations often contain small concentrations of compounds that are chemically similiar to the extrcmclv toxic dioxins. These are tlte chlorinated dibenzofurans, and the relationship is significant be cause these dioxins have produced a high incidence of birth defects in recent experiments. Small umounts of the chemicals were injected into fertile chicken eggs, producing grossly deformed chicks or the same type we have observed in the young terns. Obviously, much further re search is necessary before we can definitely pinpoint just what pollu tants are responsible for what defor mities, anil wlmt the causc-and-effcct relationships are. Bln important to point out (hat al though all tiie evidence it not yet in and weighed, what is happening to the terns on Crcat Gull Island is of critical significance--not only to the local survival of the tfieeies, but quite possibly to humans as- well. We might hyjmthesizc llint the effects of environmental pollutants, such as those mentioned, would be detected first in the tern colony. Long Island Sound is one of the more polluted areas of the world's oceans, a distinction it shares with the Baltic, the Mediterranean, and the southern Giliforniu coastal wa ters. And the effects of chemical pollutants could la: expected to up|eur first in u species tlmi is rela tively high nil tin* food chain, espe cially one that p.,.ys upon fish. 46 Not H the pregnant women who ingested thalidomide gave birth to defective children. Rather, the in cidence of defects was significantly increased. We could assume that environmental chemicals producing comparable effects would behave similarly and that their presence would not mean that all individuals would be equally affected. A nor mal-looking individual might have a higher concentration of certain pol lutants than one with four legs. Consequently, many thousands of young must be examined to detect the first effects of pollutants build ing up in a population of any spe cies. It is probable that as the levels of harmful pollutants increase in a population, more individuals will show adverse effects. But only con tinued work will verify this. In addition, high priority should be given to a detailed study of the pollutants now present in the wa ters of Long Island Sound. All of these, we must emphasize, are waste products. Normally, the waste prod ucts within an ecosystem are re cycled, used again ami again. Thus the tissues of a dead bird gradually are converted into elementary mate rial. Carbon dioxide re-enters the atmosphere to participate once again in photosynthesis, lliosphalcs re-enter the water to be in corporated once again into phyto plankton, from which they pass into 2ooplankton, then up the food chain through fish to terns, and so on. Technological man has made two fundamentalchanges in this natural process. By mining vast amounts of certain heavy metals and salts, such as phosphates, the mobilization has been greatly increased. When these become waste products in excessive amounts, the threshold of harm to certain species is passed. Also some of the new synthetic chemicals arc relatively resistant to breakdown, and so more readily build up to concentrations harmful to a great many more species. If our priorities arc rearranged to meet (he mounting environmental and biological crises caused bv the exploitation of natural systems, suf ficient warning will In; needed to provide lime to change our tech nological direction nml com mitment of natural resources. We Boulders dumped by the Army to prevent erosion cover Ute island's shoreline. It wm thought that this ruination of habitat would prevent the terns from reclaiming their lost colony, but they have adapted and now nest in the network of rocks. hsve had such warnings about air pollution, sewage in our waterways and lead poisoning, for example, and some measures are being taken to correct these threats to human health and well-being. Now the terns on Great Gull Island are is suing a warning through their piti ful deformities and threatened sur vival. That seventeen-acre island that is home to the colonv occupies a strategic position analogous to when it served as a military outpost. The terns occupying the approaches to New York City are now inadvert ently detecting a newer, more in sidious enemy to man: con taminants. Presently disturbing the reproduction of the terns, these contaminants may, aomedav soon, result in an increase in the numbers of human birth defects as thev work up through the food chain to the ul timate consumer. Fort Mirhic, now in ruins, may vet provide us with an early warning against encroaching danger. As we go to press, verified re ports ofsignificant feather loss among chicks in tern colonics in Massachusetts; Jones Reach. New York; and the On- Tortogas, off Florida. hair Urn received. The scope of the disaster is broadening. MCNS 069699