There was a slight complication the first time Bryce Robinson rappelled from the lip of a Seward Peninsula tundra cliff onto a ledge occupied by a family of Gyrfalcons. Robinson, a 29-year-old graduate student at Boise State University, sported a magnificent beard that reached to the second button of his flannel shirt. It was dense, Claus-like, brown as burnt umber, and as Robinson eased down from the cliff it got caught in the belay device that held the young scientist fast to his climbing rope. Dangling above a broad tundra river, Robinson watched in horror as a fist-sized wad of dark hair jammed in the climbing apparatus like weeds in a string trimmer. He couldn’t go up, he couldn’t go down. His only option made him weep inside. “That beard was my identity,” he recalls. Robinson pulled a knife out of his pocket and sheared the beard between rope and chin, and then watched as a softball-sized chunk of his persona was swept away by the wind like a brown Chia Pet pushed off the cliff edge.

Robinson has logged some serious cliff time since then, and I am thankful for that, because I’m dangling on a rope beside him, bundled up in a heavy down jacket despite the fact that it is June. Forty feet below our boots, another Arctic river strings through gravel, cobble, and knife-edged boulders. These are not ideal conditions for a cliff rappel, not ever, and especially not when you’re 90 miles of Alaskan dirt road from the nearest emergency room. The cliff face, rotted and cracked by the Arctic’s endless cycles of freezing and thawing, crumbles under our feet. Our ropes are strung over fractured rock so sharp that we have to pad it with our jackets to protect the ropes from being cut. Plus there are no trees, no boulders to serve as anchors. Instead the ropes are clipped to a trio of rebar rods pounded into the permafrost.

When we make it to the nest, 20 feet down the cliff, old bones glint in the Arctic twilight. There’s the breast keel of a Willow Ptarmigan, the humerus of a Long-tailed Jaeger, a carpometacarpus of some unidentified curlew. Three raptor nestlings huddle in a corner of the rock ledge, beaks agape, white downy breasts streaked with blood from their most recent meal. Robinson moves closer, cooing to the young birds as he readies his gear: banding pliers, leg bands, syringes, a digital scale, batteries, and a fresh memory card for the motion-activated camera he had bolted to the ledge weeks earlier. “It’s okay, everybody. This won’t take long,” he chatters. “Oh, nice ground squirrel tail. Good eats, guys.”

Just then one of the chicks projectile poops, shooting out a chalky, putrid stream of crap that is impressive in both volume and velocity. Later I learn that this is a common hazard for cliff-dangling raptor banders, but at the moment I’m completely taken aback. The chick’s aim is spot-on, catching Robinson squarely in the chest. I can smell the stew of semi-digested jaeger and ptarmigan from five feet away. On a cliff ledge below us, Ellen Whittle, the wildlife tech for the research project, stifles a smirk, but I bust out laughing like a 12-year-old.

“Thanks for that,” Robinson grimaces. I tell myself he’s talking to the bird.

Such are the peculiarities of doing research in one of the world’s most extreme environments, on a bird that would just as soon defecate in your face as look at you. The Gyrfalcon is the largest falcon species on Earth, with a four-foot wingspan similar in size to that of a big buteo, like the Red-tailed Hawk. In the air, Gyrfalcons are a predatorial mash-up of Muhammad Ali and Floyd Mayweather, speedy and large enough to kill a fleeing Pin-tailed Duck in midair but agile enough to snatch a Lapland Longspur off a tundra tussock.

The top avian predator of the tundra, they are handsome birds as well, typically gray and barred, although lighter-plumaged individuals can range to nearly pure white. Their demeanor and bearing have long made the species a favorite of falconers, so revered in the Middle Ages that only a king could hunt with a Gyr.

An adult female gray morph Gyrfalcon. Photo: Gerrit Vyn

“They are badass birds,” John Earthman tells me one morning as we load an ATV trailer pod with camping gear. A born-and-bred Texan and now district attorney of Nome, Earthman volunteers with the Seward Peninsula’s various raptor projects. He is part banding assistant, part ATV mechanic, and a jack-of all-trades.

He also hunts with a 16-year-old Gyrfalcon named Tinsel. “These birds recognize opportunity and take advantage of whatever is going on around them,” he says. Earthman has seen Gyrfalcons track pickup trucks and Arctic foxes to watch for flushed prey. “The birds take nothing for granted,” he says. “Even when they eat, they keep an eye on the sky.”

As tough as these birds may be, however, they survive at the delicate nexus between the frozen and the unfrozen world. Gyrfalcons range across the entire Arctic, covering North America, Europe, northern Russia, Greenland, and Iceland, and the species’ future is clouded by climate change and a shifting Arctic landscape. Warming temperatures threaten to mix up the timing of prey availability for the raptors, potentially making it harder for the birds to successfully reproduce. As Arctic seas open, shore-based freight facilities could imperil remote habitats, while an increase in high-latitude mining is already bringing more roads and people into the Gyrfalcon’s orbit.

To learn how a changing Arctic might affect the nesting success of Gyrfalcons on the Seward Peninsula, Robinson is taking a close look at how the adult birds depend on different prey at various stages of the nesting season, from when they breed to when their grown chicks fledge. He has a critical question: Is a bird that has mastered some of the most challenging conditions on Earth resilient enough to weather a warming Arctic? While current populations are largely stable, many researchers fear a slide toward endangered status.

These issues make the Gyrfalcon “the polar bear of the avian world,” says David Anderson, director of The Peregrine Fund’s Tundra Conservation Network. “It is the top avian predator of this ecosystem, and when you see changes in the populations of the top predator, it’s a reflection of what’s going on at all the lower levels of the system.”

The realm of the Gyrfalcon was once a vast, frozen no-man’s-land cordoned off by a polar ice cap and unfathomable distance. No longer. Today half the world wants a piece of a fast-thawing Arctic.

The region holds an estimated one-fifth to one-quarter of the world’s remaining untapped oil and gas stores. The rate of warming in the Arctic, faster than in any other part of the planet, could open new shipping lanes—what some call “polar super seaways”—across the North Pole, which would change how countries circumnavigate and spur a new-age land grab. Russia, for one, recently announced its intention to build 13 airfields, an air-to-ground firing range, and 10 radar stations as part of its newly formulated strategic Arctic command. All eight Arctic nations—Canada, Denmark, Finland, Iceland, Norway, Russia, Sweden, and the United States—are positioning themselves to push their flags deeply into the disappearing ice cap, but they’re not the only ones making moves on the not-so-frozen north. No surprise, China has already sent one commercial cargo vessel through the pole’s increasingly open summer waters, and plans to build its second polar icebreaker next year.

My odyssey to the land of the Gyrfalcon came off in a far less imperial fashion, to say the least. Over the course of five days we rappelled, hiked, and climbed into three Gyrfalcon nests, not one of which was easy to reach. Just to get to the cliff nest where Robinson took that fecal flash-bomb to the chest required eight hours of travel. From Nome we drove the entire 86-mile length of the Kougarok Road in 4WD pickups, hauling six-wheeled ATVs past musk oxen grazing in backyards on the edge of town. Past herds of reindeer looking like startled goats, past weird earth-covered ice formations called pingos. When the dirt road petered out at the bridge over the Kougarok River, Robinson, Whittle, and Earthman took the six-wheelers ahead, while Anderson and I hoofed it through another couple of miles of quagmire. We pitched our tents at an abandoned mining camp, scarfed down a quick dinner, then struck out on another mile-long hike and a barefoot stream crossing. By the time we set the ropes, it was already midnight. And as bright as noon.

This is the prime time of year for banding Gyrfalcons. The chicks are large enough to handle safely but still several weeks from being able to fly from the nest. While it’s most common for birds to hatch when their food is most plentiful, Gyrfalcons breed earlier than other raptors. This ensures that the greatest food abundance—young, naïve ptarmigan—coincides with the fledging of juvenile hunters just learning to kill. At the end of summer, when the majority of other bird species migrate south, most Gyrfalcons stay in the northern latitudes. The birds’ large size helps prevent heat loss, while their partially feathered legs and the ability to store more than a half-pound of fat under the skin—and another half-pound of food in the crop—help keep the cold at bay. They spend the winter feeding on seabirds and resting on icebergs in the open ocean.

Whittle clutches a nestling while Anderson fits the young bird with a leg band. Adult Gyrfalcons are powerful predators, adept at capturing avian prey on the wing as they hunt across open tundra. Photo: Gerrit Vyn

These eccentricities make them particularly vulnerable to climate change, which could uncouple the timing of their breeding cycle and food availability. Even if the timing is right, global warming could alter the tundra in other ways that might make gyr chicks vulnerable to starvation. Most ecologists believe that warmer temperatures have led to an increase in the range and size of tundra shrubs, such as alder, willow, and birch, and you can see the difference in detailed photographs taken by the U.S. Navy in 1948 to 1950 placed side by side with photos from 1999 to 2000. In some places, the shrubby landscape doubled in just those 50 years. “There has been a tremendous increase in shrub cover in much of the Alaska North Slope, the Mackenzie River in Canada, and many other studied tundra regions,” according to Gaius Shaver, principal investigator at the Woods Hole Marine Biological Laboratory’s Arctic Long Term Ecological Research Site. “And given continued climate change, you might wonder why it isn’t happening even faster.”

John Earthman lives on 18 acres of willow-choked tundra just outside the Nome city limits, and has photographs of the spread from the 1970s. “It was plain tundra out here,” he says. “There were very few shrubs of any kind.” This so-called “shrubification” of the Arctic tundra poses serious threats to Gyrfalcons because their prey—ptarmigan, primarily, but also hares and ground squirrels—can take advantage of the extra cover, making it harder for the raptors to find them.

"You spend much time up here and it is evident that climate change is not a future prediction" -David Anderson, director of The Peregrine Fund’s Tundra Conservation Network

In a warmer climate, there’s also the threat of more competition and bullying from Peregrine Falcons, which, though smaller, are more aggressive. The Gyrfalcons display a great affinity for certain nesting sites—they’ve occupied one site in Greenland for nearly 2,500 years, according to scientists—but persistent Peregrines will push them out.

“You spend much time up here and it is evident that climate change is not a future prediction,” Anderson says. “It is happening right now, and it’s building speed.” Anderson remembers walking down Nome’s bar-lined main drag last summer and stopping to chat with a local Eskimo man. Suddenly the fellow pointed to a nearby storefront—a grasshopper was clinging to the door frame. “He told me that he’d lived all his life in Nome and he’d never seen a grasshopper before.”

If tundra cliff rappelling is the sexy side of Robinson’s research, not so much the days upon days of data crunching. Thankfully my visit comes before he fires up the spreadsheets and algorithms.

But I do get a taste of his massive falcon family slideshow. Thanks to unbelievable access to tundra river country and 4,000-foot-tall craggy mountains made possible by old gravel mining roads that push up to 90 miles across the Seward Peninsula, Robinson has created the largest camera study of Gyrfalcon nests ever. To put this in perspective, a few other nest-monitoring studies have been keeping tabs on two or three mating pairs per season. Robinson installed cameras in 13 occupied nests in 2015 alone. It’s an embarrassment of riches: So far he’s analyzed more than 750,000 photographs—one at a time.

At another cliff nest, this one marked by generations worth of Gyr guano, Robinson services a remote motion-triggered camera, replacing the batteries and swapping the memory card. Photo: Gerrit Vyn

Back at his crowded rental apartment in Nome, big windows overlook gravel yards packed with snowmobiles, outboard motors, rusted hulks of ’80s-era pickup trucks, and stacks of dog kennels—no surprise, since Nome is the finish line of the famed Iditarod race. Robinson inserts a memory card into his MacBook and cues up a fantastic photo of a female Gyrfalcon on a high ledge, a tundra valley spooling to infinity below. The bird is brooding a trio of chicks in a spare stick nest tangled with the feathers of curlew and jaeger. “Look. Right here you can see her turn her head towards the sky,” Robinson says. “She’s watching the male.”

He clicks through a few more frames.

“Now she gets up to leave”—click, click—“and he immediately comes in with prey in his talons. Then he feeds the chicks and hangs out with the babies. What’s interesting about the Gyrfalcons is how much variability we see from one pair to the next. Some males have nothing to do with the young birds. Others will actually sit on the nest and brood the chicks.”

Robinson peers more closely at the laptop screen, stroking his beard, which has regrown since that traumatic shearing on the ropes. As part of his study, he tried to identify every prey item brought to each and every nest. “There’s a foot, a foot, a foot, and another foot,” he murmurs, still clicking through the slideshow, then pausing. “With that fur pattern, it could only be a Greenland [northern] collared lemming. You don’t see that very often because these birds are really optimized for taking avian prey.”

Which might be the point of it all: If I ate pizza six nights a week and then the only Italian restaurant closed, I’d switch to burritos in a snap. The question is, what about Gyrfalcons? Could the birds shift from ptarmigan to ground squirrel? Could they hunt successfully in dense alder thickets? Are they malleable enough to survive climate change? As a specialist and a top predator, Gyrfalcons will be indicators of things to come, so we’d do well to pay attention. “When stuff goes south for the Gyrfalcon,” Anderson says, grimly, “the farmer in Idaho better start watching his water allotment. The guy in Texas better keep a closer eye on his beach house. This bird is the harbinger of what is to come.”

We luck out on my last day in Alaska: The skies are clear enough for a safe helicopter flight. To keep tabs on Gyrfalcon nests too far removed to visit by foot, pack raft, or ATV, Robinson turns to a chopper, but only when the weather is just right. Taking off, we climb east to flee the Bering Sea fog bank, and then cruise the tundra at 200 feet high and 105 miles per hour. Below, rivers braid through broad valleys. I can see streams of salmon edging through gin-clear pools and caribou trails like snail tracks in a sandbar. A moose ignores the helicopter’s droning, but a grizzly sow and two cubs beat a retreat into the tundra alders. Robinson’s voice crackles in the headset. “A Gyrfalcon’s-eye view,” he says. “You can’t beat it.”

Robinson extracts an unfledged Gyrfalcon from its nest so it can be banded, weighed, and measured. His Gyr study is the largest ever conducted. Photo: Gerrit Vyn

At $950 an hour for the chopper and pilot, though, there’s little time for rubbernecking. Robinson has the coordinates of his target nests logged into a GPS, though as we near the sites, it’s pretty easy to pick out the ledges where gyrs are. A Gyrfalcon nesting cliff is part compost pile, part rubbish heap, part toilet, and part graffiti wall for the lichens, fed by the nitrogenous whitewash, that paint the rock ledge orange. We can spot the lichen colonies from miles away. Below the nests, rotting ptarmigan pieces and parts fertilize the thin, meager soils. And voilà! Lush green grasses sprout thigh-high, attracting another micro-community of rodents and breeding songbirds such as Say’s Phoebes, which benefit from the gyrs’ tendency to aggressively protect their own nests.

We slalom from mountain range to river canyon, Robinson calling out nest status and chick numbers while Whittle confirms the sightings and tallies the birds on a data sheet. The flight is a birder’s Arctic dream: I see Cackling Geese on their cliff-face nests and Canvasback ducks on tundra ponds. Robinson points out a pair of Bristle-thighed Curlews flapping in the airspace below. These nest in only a few places in Alaska; it’s likely that fewer than 10,000 remain on the planet. It’s one of the most sought-after bird sightings in this part of Alaska. “Oh, man, David is gonna be pissed,” Robinson says. “He’s tried to spot one of those for three years straight.”

Then, suddenly, Robinson sounds an alarm. “Gyr in the air,” he says, jabbing a finger toward a looming cliff wall so tall it casts a shadow inside the helicopter. He’d warned the pilot earlier that the birds seem to have little fear of aircraft; he’s seen Gyrfalcons charge a helicopter in flight. Now he’s on the edge of his seat, twisting to keep his eyes on a bird that only he can see. “Let’s get out of here,” he says.

The pilot banks the chopper, and I press my face to the bubble of glass, searching for the raptor. I never find it, but I do see its shadow as it races down the cliff face a hundred yards away, then streaks out over the Arctic tundra, where change is coming with a swiftness and sureness the bird cannot comprehend.