The Sound of Migration
by Sandra Steingraber
ONE APRIL MORNING, in the middle of a predawn testimony to the mirthfulness of robins, I hear fluttering right outside the bedroom window. I lift the blind, expecting to see either a creeper or a nuthatch. Instead, a trio of tiny olive-green heads stares back at me. One hops closer, blinks, then bobs his head, the top of which is painted bright pink. “Well, who are you?”
As if in answer, the bold one bows to show me again his splendid little cap. Then more fluttering and prancing around at the ends of the maple branches. Then all are gone. I know I won’t sleep again until I can identify them, so I pull back the blankets and pad out to my study. Somewhere in the stack of boxes on the far wall is my bird book. As I’m pulling boxes down to find it, I’m aware of my belly - harder now and rounder, not just thicker. The window on this side of the house is still dark enough to be a mirror, and, backlit, I can see an obviously pregnant body through the thin white cotton of my nightgown.
“Who are you?” I ask for the second time before sunrise.
I make a good guess with the boxes, and find my grubby field guide to the birds wedged between two stacks of textbooks. I start flipping through the section on songbirds. It doesn’t take long. There is only one olive bird with a pink spot on its head, and it is famous both for its fearlessness and for fluttering around at the ends of twigs: the ruby-crowned kinglet.
The next morning there is a new song in the mix - a thin little violin voice calling Old Sam Peabody, Peabody with a plaintive fade-out at the end, as if further searching would be futile. This is a white-throated sparrow, a bird I know by heart. I peer out the window to see if I can locate it. Instead, I find the maple branches full of kinglets. Dozens of them, all tipping their caps and bounding on the bud-swollen twigs.
There is the white-throat song again, even closer. And then again. Old Sam Peabody, Peabody. But I can’t find the singer. I’m looking for inconspicuous black and brown feathers, a gray breast, a white throat. Nowhere.
The next morning I wake at 3 a.m., absolutely convinced I hear a veery singing. I lie in the darkness - as yet undisturbed by robins - listening for it again. Nothing. Finally, I pad back to my study to check the bird guide. According to the book, it’s not possible that I just heard a veery. Its earliest known arrival date in central Illinois is April twentieth - two weeks from now. Also, it’s a bird of deep woods, not backyards. Also, it doesn’t sing in the dead of night. I must have been dreaming.
I climb back into bed but can’t sleep. In the fourteenth week of pregnancy, I’ve entered a new phase. Torpor has given way to a state of high alertness. I’m more watchful, and my sense of hearing seems to have become more acute, too. With my new powers of perception, I try listening for the sound of songbirds migrating.
This isn’t as far-fetched as it sounds. Serious bird scholars often go out on damp spring nights and listen for the faint chip chip chip of birds calling to each other as they pass by, a thousand feet overhead. Master birders can identify them to the species just by the pitch and timbre of the distant flight notes.
A lot of mystery still surrounds the migration of songbirds. For one thing, they only travel at night. For another, most are too small to wear radio transmitters. Therefore, most of what we know about their spring and fall travels comes from radar, which can only track groups, not individuals. Before radar, researchers estimated the intensity of songbird migration by moonwatching. This was a quaint but highly skilled practice that involved counting the number of birds seen flying across the face of the full moon. It required clear skies, a telescope, and elaborate calculations to account for angles of entry, altitude, and percentage of night sky occupied by moon. Moonwatchers made fantastical claims: two hundred bird silhouettes crossing the lunar window in an hour meant that three million migrants had passed by. Which meant that billions of birds were on the move during particular nights of the year. There was a lot of skepticism about these extrapolations until they were confirmed by radar operators.
I must have dozed off because I suddenly become aware of robins caroling. And then Sam Peabody, Old Sam. I creep to the window ledge and let my eyes adjust to the dimness. Empty branches. No sign of the kinglets today, and no white-throated sparrows. Either I’m a truly incompetent birder or the tree itself is singing. Jeff stirs in the bed.
“Sandra, what are you doing up? Are you worried about something?”
“Hang on a minute.”
Silence. More robins.
“Shh. Just listen with me.”
Old Sam Peabody...
“Did you hear that? I think we’re having a son.”
ON THE NIGHT OF THE FULL MOON, I am fifteen weeks pregnant and in Boston, having flown here for an amniocentesis. This was a huge decision - whether to have the test at all, and if so, where. Actually, the where question was easier to answer. My so-called health maintenance organization refuses to pay for nonemergency health care outside of Massachusetts. The question of whether to do it at all was more complicated.
Amniotic fluid is the oceanlike substance unborn babies float in. It offers fetuses buoyancy, protection from trauma, and oxygen. Like semen, amniotic fluid is comprised of two basic elements: living cells and the liquid they’re suspended in. In this case, the cells represent sloughed-off fetal skin and bladder tissue. Amniocentesis means puncturing a pregnant uterus and aspirating about thirty milliliters - one shot glass full - of amniotic fluid, which is then sent to a genetics lab for examination. The cells it contains are grown in tissue culture to increase their numbers and then inspected for chromosomal defects. This takes about ten days.
In the meantime, the liquid fraction is run through a gauntlet of tests that can reveal the presence of other abnormalities. By subjecting to scrutiny both the liquid and the cells, amniocentesis can potentially uncover hundreds of different congenital problems. Extracting this fluid from the belly of a pregnant woman is not, however, without its dangers. Specifically, amniocentesis triggers miscarriage in about one in every two hundred women.
And yet, I have decided to go ahead with it. In the end, knowing simply seemed better than not knowing. Two big facts of my life are relevant here. The big fact that I am a cancer survivor. The big fact that I am an adoptee.
Having been diagnosed with cancer - in my case, bladder cancer at age twenty - means that I’ve been badly betrayed - not only by my own runaway cells but by those who issue medical reassurances along the lines of “don’t worry, the odds of there being any sort of problem here are negligible.”
The adoption piece is more bewildering. Now that I am pregnant, I find myself wondering about it more. Thinking about my adoption is like looking at faraway stars. It makes me feel small and vaguely sad. Being adopted and pregnant also presents some large practical problems. The primary one is that I have no information about my family medical history. In most states of the union, including Illinois, adoption records are still sealed by law. The adoption agency that handled my case is more sympathetic than most to the abridged civil rights of adult adoptees, but sympathy cannot answer the questions the genetic counselor had for me - any cystic fibrosis in my family tree? Tay-Sachs? Thalassemia? Spina bifida? Mental retardation?
I agree to submit my baby’s chromosomes for analysis in part because I know nothing about my own. Which leads to the vexing paradox that the first information I learn about my unborn child will be exactly the kind of information I lack about myself. Of what value is this knowledge? I’ve absolutely no idea.
THE SMALL, DARKLY LIT ROOM in the sonography unit at Boston’s Beth Israel Hospital fills up with women - my friend Janaki, my gynecologist. The technician and the chief sonographer take their places and begin flipping switches and unwrapping the assembled objects. They begin quickly.
The dome of my belly is bared to the ultrasound probe, which looks like the kind of spoon that you eat Japanese soup with. The probe locates a pocket of fluid safely away from the body of the fetus. The needle slides in about two inches below my navel. A second later, as it passes through the uterus, I feel a sharp cramp.
” Normal,” my obstetrician says breezily.
Everyone else is watching this moment on the screen of the ultrasound monitor. I am not. I am thinking very hard and very deliberately about hummingbirds.
The nests of hummingbirds are constructed of spider webs and dandelion down. They are lined with lichens and moss. They usually contain two eggs.
I glance down briefly. The syringe is half full of fluid.
The eggs are the size of peas. When baby hummingbirds hatch, they are said to resemble wet bumblebees. “Normal” is a very nice word.
The first syringe is replaced by a second.
Hummingbirds fly over the Gulf of Mexico from the Yucatan in a single night. It’s a distance of five hundred miles. Some of them probably came across last night - assuming the high pressure system over New England extends all the way down there.
The second syringe seems to be taking longer to fill up.
In truth, I don’t like hummingbirds. Up close. They’re too spangly and too impossibly small, with too much nervous, insectlike whirring. Still, the entire Gulf in a single flight is impressive.
The needle is out. We’re done. The obstetrician hands the pair of vials to the technician who holds them up to the light like glasses of fine wine.
“Nice color,” she says. “Do you want to hold them?”
And she passes the vials, hot as blood, into my hands. The fluid inside is pale gold. It seems to glow.
“It’s like…liquid amber. Like an amber jewel.” It occurs to me that amniotic fluid might be the loveliest substance I have ever seen.
The obstetrician touches my arm. “That’s baby pee,” she says, smiling. “We like it yellow. It’s a sign of good kidney functioning.”
I look at the vials again.
AMNIOTIC FLUID IS A MIXED DRINK, with contributions from both baby and mother. Some portion of amniotic fluid is secreted by the lining of the amniotic sac itself, and some of it is blood serum from the mother, which passes freely through this lining. And some of it is baby pee. Fetal urine is distilled from amniotic fluid, which is continuously sipped and swallowed by the baby. Amniotic fluid also soaks right through the skin because the outer waterproofing layer doesn’t form until week twenty. The fetus also inhales it during rehearsals for breathing. In these ways, amniotic fluid bathes the inside as well as the outside of the developing body.
Amniotic fluid is a biological mystery. It is bacteriostatic - meaning that bacteria will not grow when cultured in it - so amniotic fluid undoubtedly helps keep the womb a sterile place. But what it does once it seeps inside of the fetus - through the mouth, through the lungs, through the skin - is not at all clear. Some researchers suspect it plays an integral role in establishing the fetal immune system.
Amniotic fluid eventually reenters the womb as urine. Here it is absorbed back into the body of the mother and replaced by fresh fluid, in a ceaseless cycle of emptying and refilling. This process speeds up as pregnancy progresses. At fifteen weeks, the baby and I require twenty-four hours to replace the volume of fluid just removed.
The obstetrician is finishing up. She reminds me to drink plenty of water today.
Drink plenty of water. Before it is baby pee, amniotic fluid is water. I drink water, and it becomes blood plasma, which suffuses through the amniotic sac and surrounds the baby - who also drinks it.
And what is it before that? Before it is drinking water, amniotic fluid is the creeks and rivers that fill reservoirs. It is the underground water that fills wells. And before it is creeks and rivers and groundwater, amniotic fluid is rain. So that when I hold in my hands a tube of my own amniotic fluid, I am holding a tube full of raindrops. Amniotic fluid is also the juice of orange that I had for breakfast, and the milk that I poured over my cereal, and the honey I stirred into my tea. It is inside the green cells of spinach leaves and the damp flesh of apples. It is the yolk of an egg. When I look at amniotic fluid, I am looking at rain falling on orange groves. I am looking at melon fields, potatoes in wet earth, frost on pasture grasses. The blood of cows and chickens is in this tube. The nectar gathered by bees and hummingbirds is in this tube. Whatever is inside hummingbird eggs is also inside my womb. Whatever is in the world’s water is here in my hands.
CAUGHT UP IN THE ANCESTRY of amniotic fluid, I almost forget to look at the ultrasound monitor where, in a kind of silent movie, the baby is swimming around, sans needle. The technician is explaining that she has two ongoing purposes here - to see how the fetus has reacted to the procedure and to take some measurements.
A sonogram is a picture made of echoes. More specifically, obstetrical ultrasound bounces high frequency sound waves against the body of a living fetus and then converts the returned energy into electrical signals, which are visually displayed on a computer monitor. I know plenty of women who experience their fetal sonograms as an ecstatic event, but I bring a whole different set of associations to the sonography table. I’ve lain in this semi-darkened room before, for the purpose of being scanned for signs of a tumor. On those days, the only heart beating was the one pounding against my own rib cage. On those days, I hoped to see nothing. I have to remind myself that the discovery of a growth in my abdomen is not a bad thing this time.
“Look, Sandra, there is the spine. Can you see it?”
Out of the grainy darkness, a strand of pearls floats into view. Around it an entire human form takes shape. I see a back, an ear, a head. And then the vertebrate body abruptly rolls over, like a sea mammal executing a turn in an aquarium tank. And then two arms fly up in synchrony and come back down and fly up again. A small bird migrating across an open ocean. A white silhouette against the black moon of my own body.
And for the third time this week, I peer into a window, asking, “Who are you?”
TWELVE DAYS AFTER my amniocentesis, I am scheduled to fly across the Atlantic for a two-week book tour of England and Ireland. I’ve been assured that “almost certainly” the results of the amniocentesis will be back from the lab before we leave.
Meanwhile, the myrtle warblers arrive in Illinois for a few weeks’ stay and flash their yellow rumps in the tree branches, calling check, check, check, as though testing microphones. Myrtles are tough little birds, withstanding late snows in the spring and fueling themselves with poison ivy berries in the fall. Sadly, they are often killed in collisions with broadcast towers. In October 1985, more than three hundred myrtle warblers were found dead beneath a television tower in Springfield, Illinois, on a single night. I wonder what will happen to the myrtles as the rage for wireless communication raises more and more of these structures across the prairie.
Television and cell phone systems are not the only hazards. Later in the week, I have lunch with Given Harper, a local biologist who has been studying pesticide contamination of Illinois birds. He’s particularly interested in analyzing their tissues for the presence of organochlorine pesticides. DDT is probably the most famous representative of this family of synthetic chemicals. All members of the clan poison insect nervous systems. But many chlorinated pesticides have two other properties once they enter the environment at large. Like mercury, they biomagnify - they concentrate as they move up the ladder of the food chain. They also possess the power to redirect hormonally directed biological processes.
Harper and his colleagues collected songbirds during the spring migration of 1996 - many of them tower kills - and analyzed their tissues for the presence of these chemicals. The bodies of more than ninety percent of the seventy-two birds he studied contained at least one such pesticide - and often three or more. The most common pesticides detected were dieldrin, heptachlor, and DDT. In keeping with the principle of biomagnification, birds dining higher up on the food chain - the insect-eating warblers and flycatchers - carried higher burdens of pesticide than the vegetarians, such as grosbeaks and indigo buntings - although these species, too, were contaminated.
ON FRIDAY, ONE WEEK AFTER the amniocentesis, the tattoo beneath my belly button has completely vanished. I decide to call the obstetrician’s office in Boston. Just to check in.
No, says the receptionist, the results are not back yet.
I spend the weekend walking the Constitution Trail, a paved north-south path, previously a railroad track, that slices through miles of backyards, loading docks, athletic fields, city parks, and even a patch of prairie grass. The daffodils are in full bloom, competing with forsythia bushes for brilliance of yellow. The cardinals singing in their branches have never been redder. Nor have the tulips. The puffed-up robins patrolling the newly green grass refuse to be silenced by the gravelly roar of the roller-bladers. I am attracting knowing smiles from mothers pushing strollers. Spring is an out-of-control carnival. I am out-of-control pregnant.
The cells of my baby are growing not only in my body but somewhere in a laboratory in Boston, where they are bathed in a broth made from fetal calves. Only about ten percent of the cells captured during amniocentesis are alive, but these can be coaxed to grow and divide if carefully nurtured in an incubator at human body temperature. At some point, usually five to nine days later, these living cells can be harvested for genetic analysis. Chromosomes normally exist inside cells as slender, loopy threads of DNA which are impossible to study. Only when a cell is preparing to divide are its chromosomes transformed into the stout, rod-shaped bodies that grace the pages of science magazines and biology textbooks. Thus, the fetal cells collected for genetic screening have to be arrested in their growth cycle just at the point where they are about to split into two. The chromosomes must also be stained to bring out their individual banding patterns.
A human being is supposed to have forty-six chromosomes. Half of these are inherited from the mother, half from the father. Matching them up is the first task of prenatal genetic screening. At the end of the day, one hopes for exactly twenty-three matched pairs. Anything else has serious consequences for development. An extra chromosome, for example, is called a trisomy. With three copies of petite chromosomes 21, Down syndrome is the classic example.
I wonder where in this process my fetal cells are. Still quietly incubating? Or have they already been harvested, stained, and photographed, their chromosomes spread across a computer screen, magnified a thousand times? Perhaps at this very moment, while the Illinois sun slants through ironwood trees and while pigeons clatter under the slats of old train trestles, someone in Boston is sitting down with a fresh cup of coffee to start the sorting and counting. Maybe there is a radio playing in the lab. Maybe the report is already typed up.
What’s starting to bother me about amniocentesis is not the anxiety it creates (which is considerable) nor the cold-heartedness of it (also considerable), but its narrowness of focus. The whole enterprise implies that the future life of a child can be read by counting its chromosomes and scrutinizing their architecture. But the children of Minamata crippled by mercury poisoning had perfectly normal chromosomes. So presum-ably did the thousands blinded by rubella and the legless ones exposed to thalidomide. Indeed, the majority of birth defects are not attributable to inborn genetic errors. And yet we put legions of geneticists to work looking for them, and we ritualize amniocentesis as a rite of passage for pregnant women, as though chunks of DNA were the prime movers of life itself. As though pregnancy took place in a sealed chamber, apart from water cycles and food chains.
What if amniocentesis inquired about environmental problems as well as genetic ones? Only one study of environmental contaminants in amniotic fluid has ever been done, and it found detectable levels of organochlorine pesticides in one-third of the thirty samples of amniotic fluid tested. Of particular concern, say the researchers, is the discovery of DDT, which was found in concentrations roughly equivalent to that of the fetus’s own sex hormones. Because DDT is known to interfere with the biochemical pathways that sex hormones operate along, the question arises as to whether this kind of contamination can alter the unfolding development of the fetal reproductive tract. The researchers also found trace levels of PCBs in some of the samples. These chemicals not only have been linked to birth defects but are also thought to suppress the immune system. Amniotic fluid itself is believed to play a role in establishing fetal immunity. Are inhaled and swallowed gulps of PCB-laced amniotic fluid sabotaging this process even as they initiate it? No one knows, but the answer would be relevant to all unborn babies, not just the very few who have inherited the wrong number of chromosomes.
The chemicals being discovered in human amniotic fluid are, of course, some of the same ones that Given Harper is finding in the tissues of migrating and resident birds. I think back to my own amniocentesis epiphany. Whatever is inside hummingbird eggs is also inside my womb. Whatever is inside the world’s water is also here in my hands.
MONDAY, DAY TEN. It’s very possible the results will arrive today. But when I get home from my afternoon class, there is no message on the answering machine. So I call again.
No, I’m sorry, says the nice receptionist. They didn’t come back today. Don’t worry though.
Tuesday. I call again.
Oh, hi, Sandra. No, we still haven’t heard anything. I know you’re leaving tomorrow. Call us before you head out for the airport.
No, we don’t have the results yet. What time is your flight?
Wednesday afternoon, at the O’Hare airport:
I’m really sorry. The lab hasn’t returned my phone call. As soon as I hear anything I’ll leave a message on your answering machine.
Thursday, from a hotel room in London:
Friday, from a phone booth near Hyde Park:
Friday night, from a phone booth next to a cemetery in Kent:
Sandra, we’ve got the results. The chromosomes are normal. And you’re having a little girl.
A blackbird is singing in the medieval churchyard where Jeff and I are dancing.