by Sue Halpern
THAT TRANSLUCENT MONARCH we saw noodling around Bill Calvert’s study site was the last one of 1997 that I saw. Two other monarch butterflies settled into the Indian paintbrush that afternoon, but they were bright orange—fresh ones—as were the few I found nectaring along the highway as I headed into Houston the next day. The fresh ones were the freshmen of 1998. By the time I’d start to see monarchs again in the Adirondacks a few months later, they would be three, maybe four generations removed—seniors, or postgraduates, to stretch the metaphor. But that assumed that each generation would do its part. That the chain would not be broken. Yet that, observers in the southern tier began to notice, was not what was happening. There were fewer monarchs, for one thing, or at least fewer monarchs being sighted, as Bill Calvert had told the readers of D-Plex just a few hours before I got off the plane in Austin.
“In general we are not seeing as many adults or eggs and larvae as we did last year at this time,” he wrote. “The greatest numbers of adults were seen in late March and very early April. Since then numbers of adults have tapered off. We continue to see eggs, but not very many. It may be a ho-hum year for monarchs!”
But ho-hum it wasn’t shaping up to be. The numbers were definitely down. A comparison of sightings reported to Journey North showed that during the first two weeks of April there had been fifty-nine sightings in 1997 and only twenty-three in 1998. And that was not all. Monarchs were showing up in strange places at strange times. One was seen crossing Bancroft Point on Grand Manan Island in New Brunswick, Canada, on May 4, nearly two weeks before a monarch had ever been seen there before. And then there were the fifty monarchs seen crossing the Gulf of Mexico, flying against the wind. That one caused a lot of speculation, but one man, David Gibo of Toronto, didn’t find it peculiar at all. Gibo, as I was soon to find out, was a glider pilot with an encompassing interest in flight vectors. He was also a biologist, a professor at the University of Toronto at Mississauga. Those fifty monarchs had probably been riding thermals, Gibo supposed, and when a thermal that has formed over land drifts over water, the warm air feeding it is cut off and it breaks up—in this case causing the monarchs to descend and forcing them to fight their way back to land. “Were the butterflies simply unlikely individuals that happened to have started too close to the coast when they picked up their first thermal of the day?” Gibo asked. “Probably. Were these sightings unusual? Not at all.”
Even so, the numbers were down significantly, and no one knew why. Fire, drought, and logging were the obvious culprits, but so was nature itself. Population fluctuations had been observed for so long that some biologists, most notably Fred Urquhart, thought the monarchs were on a seven-year boom-and-bust schedule that reflected the rise and fall of certain parasitic killers. It wasn’t so, at least not the cyclical part, though disease could be rampant. When I got home I called Bill Calvert to get his opinion.
“Why are the numbers down?” I asked him.
“Are they?” he replied.
“Well, the number of reported sightings is down,” I said.
“Right,” he said, making his point. I decided to change tacks.
“What if the numbers were down this spring? I mean, they were so high last fall, what if the spring population basically crashed? Why would that be?”
There was silence for a moment, and then, if a smile can be audible, I heard one traveling across Bill Calvert’s face.
“That’s a good question,” he said.
Chapter 8
THE MILKWEED BEHIND my house began to reassert itself, slowly at first and then with more vigor. Two inches in the beginning of May; ten more by month’s end. Green with promise, it stretched skyward, adding leaves and stem, then more leaves and more stem, like a stunt done with mirrors. The raspberry canes that had lain brown and dormant among the milkweed began to wake, too. Horizontal on the twelfth of May, they had sprung some twenty degrees two weeks later and continued degree by degree, like someone rising from a long and deep sleep, till, heavy with fruit, they stood perfectly vertical amid the tangle of milkweed.
The birds came then, the thrushes and the warblers, and then the butterflies and the bees. Traffic was heavy with all their comings and goings. Pollination, copulation, oviposit-ing, and predation were undertaken with such diligence that I began to think of the milkweed patch as a small enterprise zone or industrial park. There were beetles and earwigs, ants and wasps. And spiders and grasshoppers. What there wasn’t, though, was monarchs. The monarchs were conspicuously absent. In years past there had always been a few in early summer, outliers who had come up from the Midwest on a northern wind, second-generation migrants whose offspring might head up to Canada or stick around and breed the generation that would go down to Mexico. But this was not a typical year. The monarchs were missing, and not just from my backyard, and not just in May, and not just in June. Not one monarch butterfly lit upon the joe-pye weed that grew casually around the perimeter of the property. Not one was sighted on the goldenrod in August. Their absence was a kind of visual silence—an anxious visual silence. The monarchs always seemed about to appear, but then they never did. And no one could say where they were.
But the world, even the world of my backyard, is a big place. It was possible that the monarchs that were not on my property were two miles over, on my neighbor’s. It was possible that they were in Franklin County, not Warren County, or in Quebec, not New York. Or in Vermont, or Maine. Just because they could not be seen, it didn’t mean they were not there. Empirical knowledge is tricky that way. Things unseen are not necessarily things not there.
Some days, walking around the yard, turning over the newest milkweed shoots to look for monarch eggs and caterpillars, I found it miraculous to think that I had seen monarchs (and eggs and larvae) there in the past. They were so small, and so scattered. But they had been there; against the vast backdrop of earth and sky, they had shown up. And if the consolation of empiricism is truth found in regularity, when things stop happening it is unsettling. This was in August. Clusters of mallards and mergansers had already taken to the air. I decided to, too.
“JUST SO YOU KNOW,” I said to the man on the phone, in the interest of full disclosure, “I really don’t like to fly.”
“Many people are afraid of flying,” he said in a soothing voice. “But they haven’t really flown.”
“I fly all the time,” I said. “I can’t tell you how many airplanes I’ve been in in the past year.”
“Did the airplanes have engines?” he asked.
“I assume so,” I said.
“So you haven’t really flown, either,” he concluded.
THE MAN ON the other end of the line was David Gibo, the University of Toronto biologist and glider pilot. Gibo had logged hundreds of hours in his Grob 103 ACRO, a two-seat, engineless fiberglass aircraft with a wingspan twice as wide as a Piper Cub is long. A glider is lifted into the air by a tow plane, which unhooks it at two or three or five thousand feet or more, leaving it to find its own way back to the ground. It was in the air that Gibo began to understand how a monarch butterfly could travel thousands of miles and end up on the side of a mountain in Mexico without apparent damage. But it was from the butterflies that he first learned how to fly.
“One September day I glanced out of my office window and saw a monarch,” he recalled. “I had just learned to glide myself and I was looking out the window to see if it was going to be a good weekend to drive out to the glider club. I saw this butterfly coming toward the building and it started going up and got about a third of the way and then stopped flapping. From then on it went back and forth, turning figure eights or circles, I can’t remember which, until it went up and over the building. I said ‘Hmmn,’ and I knew what it was doing, because if it wasn’t flapping its wings it was coming down, unless it was in air that was going up. Buildings, like mountains, create lift.”
This was in the mid-1970s. Fred Urquhart’s National Geographic article extolling the seemingly valiant, enigmatic, long-d
istance journey of the monarch butterfly had just been published. So it was known where the butterflies spent the winter. What was not known was how they got there. And then David Gibo, a wasp guy by trade, saw the monarch catapult the South Building, and it gave him an idea.
“I decided to study flight tactics,” Gibo said. “The solution for that seemed obvious. All I had to do was build a powered ultralight aircraft, add a few extra instruments, then fly in the vicinity of the migrants.”
But it didn’t work that way. Gibo built the plane and hauled it down to Texas at the height of the migration, taking off on a day when he could plainly see thousands of butterflies overhead. See them, that is, till he was part of the sky himself. “All my equipment and theories about air currents could not help me see what amounted to a piece of paper set on edge against the horizon, and a camouflaged one at that,” he said. “Look down, no butterflies. Look ahead and to the side, ditto. I finally realized that I could see them if I looked up, but that isn’t a very safe way to fly. Especially at low altitudes.”
Gibo stopped looking for monarchs when he was in the air and concentrated on becoming an expert flier himself. If he understood aerodynamics better, he reasoned, he would understand how an insect with a three-centimeter-long body could travel forty-five hundred kilometers through the air—a feat, he calculated, akin to a six-foot-tall person’s circling the globe eleven times in a row. But the monarch was not a person, it was a bug, a bug with a bug’s brain. Or as David Gibo liked to say, it was aerial plankton with a guidance system. How complex could it be?
“Without a doubt, [the monarchs”] annual two-way migrations are among the most amazing accomplishments of insects,” Professor Gibo assured readers of his flying, gliding, soaring, and science Web site, Tactics and Vectors, some of whom, he knew, ascribed spiritual dimensions to the unlikely, and seemingly miraculous, journey of the monarch, as if it were nature’s vision quest. “Nevertheless, it can’t be that difficult. We’re talking about an insect. Like all insects, butterflies are strong and resilient, but lack special (i.e., magical) powers and are prone to all the limitations that accompany small body size. Compared to migratory birds, migratory butterflies are much slower [and] have an inferior capacity to regulate their body temperature and an absolutely ridiculous rate of fuel consumption during powered flight. In short, there seems to be nothing to recommend the butterfly body plan, physiology, and nervous system for the task of making regular, long-distance, directed migrations.… Nevertheless, each year millions of butterflies, who apparently haven’t the good sense to recognize their serious design flaws, somehow manage to make their way across the continent. Apparently, we’re overlooking something important here.”
What he meant, and he wasn’t being pejorative, was that it couldn’t be all that complicated. Bugs were bugs. Biologically, physiologically, they were capable of only so much. They were scripted at birth. They followed a distinct genetic set of rules that directed them to fly to the overwintering sites and back. Gibo believed that those rules were discernible. He wanted to uncover them.
“Let’s say that there is an international airport and we want to find the regulations that apply to different categories of aircraft,” he said to me, reaching for an analogy that he thought I might understand. “We also want to know which runways they take off from, and how it is aligned, and what the requirements for noise reduction are. If I just watched what was happening and recorded it, at the end of a year’s observations I would say, ‘OK, here are the regulations.’ I’d be able to infer the rules.”
What Gibo did not mean—and this was central to his way of thinking—was that the rules were about probability, the way, say, Adrian Wenner’s dispersal model was, or about randomness and chaos, the way a model based solely on weather might be.
“Monarchs don’t simply show up wherever the wind blows them,” he pointed out. “They seem to show up where it is beneficial to them, at a higher latitude at the right time of the year, where the crops or fruit plants are. And this seems to be more predictable than what we expect from the weather patterns. I think that going and getting descriptive data and exploring them will give more insight into what’s happening than using meteorological data and generating hypotheses that way.”
IT WAS THE MIDDLE of August in the summer of the absent monarch butterflies. In less than two hours I would be airborne with David Gibo, flying in a two-seat training glider above the farmland surrounding Arthur, a small agricultural village in southern Ontario, about an hour west of Toronto. We had driven up at midday, stopping for lunch at the local diner, a spare eatery with little to recommend it except that it was there and reliably patronized by members of the York Soaring Association, Professor Gibo’s glider club. Though he was so engrossed in a conversation with a fellow pilot that he kept forgetting to look at his menu, I was obsessed with the French fries and chocolate milkshake that I ordered with abandon on the theory that this might well be my last meal. And if we didn’t crash, if I didn’t die, I kept asking myself, would I be revisited by this food at fifteen hundred feet?
“In most planes, stability is a good thing,” the other pilot was saying to David. Did that mean that gliders were not stable? I wondered. Flying in an airplane without an engine—this was definitely the most dangerous thing I’d ever done on purpose. And it was on purpose. I wanted to feel what it felt like to be carried along by wind. Or I had wanted to feel it. An hour, now, from takeoff, and I was no longer sure.
“Being stable requires less energy,” the other pilot said loudly. He had an Australian accent and a confident manner. Gibo had told him I was going up for the first time, and I had the feeling that this speech about stability—a very calming word—was for my benefit exclusively.
“Monarchs are stable in their gliding configuration,” David said. “If they have an active control system, their nervous system and muscles are going to be operating, and they’ll use more energy.”
This I understood. A monarch can carry only about 125 milligrams of lipids—its fuel—in its body. It takes just ten hours of powered flight—the kind of flying that is characterized by beating wings—to deplete that store.
“The idea is to get from here to there with as little energy used as possible,” David said. “On the other hand, when they’re attacked they have to go into violent maneuvers. They can flap and unflap their wings and beat them in different planes.”
But what about us, flying in a craft with fixed wings and no fuel? What did we have to work with?
Not a lot, it turned out. At the gliderport David showed me our plane, a battered twenty-five-year-old Schweizer 2-33 trainer. Disproportionate to the airplane’s body, like the arms of a rangy teenager that had grown faster than his torso, the wings spread out on either side of a remarkably small and compact hull. The hull was painted orange in a somewhat haphazard manner, the green and black of earlier paint jobs peeking out here and there. The steel housing was battered and pinged, and the effect was hardly reassuring. It looked like a jalopy.
The glider’s wings were orange as well, and rounded on top—airfoil wings. This, I knew, would help keep us aloft. As air moved over the top of the wing, the airfoil would slow it down and disperse it. With more pressure below the wing than above it, the airplane would be pushed upward. This was lift. A monarch’s wings were orange with black, too, but all similarities ended there. Butterfly wings were flat. Lift came from flapping, from churning the air until it created a whirling mass that moved along the leading edge of the wing.
The gangly orange sailplane, though not nearly as elegant as an orange-and-black monarch, had certain mechanical advantages over a butterfly. It had a rudder, located near the tail, that kept the fuselage aligned with the direction of flight. It had a pair of ailerons, one per wing, that controlled airflow and offered lateral control. It had elevators on the tail to make the nose point up or down. It had spoilers to reduce lift. Each of these was available to the pilot should he wish to change the airplane’s flight a
ngle, its altitude, or its direction.
Professor Gibo was explaining this as we hoisted ourselves into the rudimentary and snug cockpit, me up in front, he in the back. Feet forward, I wriggled into place like a sausage being packed into casing. The plane—the inside of it, anyway—was narrow and tinny. There just wasn’t much of it. And once the Plexiglas canopy was lowered, it seemed smaller still. Not a good place to be a claustrophobic, I was thinking, looking out the bubble overhead. Or to be a control freak, either, since there were almost no controls. Just the altimeter, rudder pedals, spoiler aileron, and elevator stick, and the tow-release knob to disengage the umbilicus connecting the glider to the tow plane.
“I don’t need to know about any of these, right?” I called to David, looking for assurance that he, indeed, would be piloting the plane. But David couldn’t hear me. The tow plane was buzzing up ahead and the yellow rope between us was losing its slack. After another second it grabbed the little orange glider as if it were a recalcitrant child and pulled it down the grassy runway. We clattered along, then lifted off the ground for a second like a kite on a short string, dipped back down, then took off again for real as the yellow rope stretched and grew taut. Twenty, fifty, one hundred feet and climbing. As I looked down at the receding ground, a line from a nameless poem went through my head: “From this there’s no returning, none.”
“Watch the tow rope,” David called out to me over the loud, maddish complaint of an airplane being yanked through the air. “You’ll know when we’re going to hit a bump because you’ll see it in the rope first.” I guessed this made me feel more secure, though “more secure” might suggest that I felt somewhat secure, which at that moment I did not. We were bobbing around pretty regularly, mirroring the fits and starts of the tow plane but on time delay, like bad lip-synching. Still, knowing when it was going to happen let me tense up beforehand and brace myself.
