Keywords: Birds, Marine birds, Disease, Monitoring, Salish Sea Currents magazine

A new strain of avian flu has been sweeping the globe since 2020, leaving thousands of dead seabirds in its wake. This past summer, it arrived at a colony of Caspian terns at Rat Island in the Salish Sea, with catastrophic results.

The small gray inflatable backs away from Rat Island, turns, and zips over the short stretch of water towards the dock on the mainland. I watch its progress as I trot to the dock, but Chad Norris, who is driving, waves me away when he nears. “I’ll come to you!” he calls. “I have to get your PPE out of my truck!”

So I wait as Norris, a technician with the Washington Department of Fish and Wildlife, ties up the boat and lopes up to his truck, the loose legs of his Tyvek suit flapping. From the bed of his pickup he hands me a shrink-wrapped Tyvek suit, an N95 mask, and my choice of goggles or safety glasses. These are the standard accoutrements when one visits a place where there is an ongoing outbreak of highly pathogenic avian flu. A place like Rat Island, in other words.

Once I am suited and booted, we go to the boat and Norris steers away from the dock. Soon we are flying back to the island. “It’s pretty quiet today,” Norris says over the outboard’s high whine. “So I guess that’s good.”

We near the island, and I can see three other Tyvek-ed and goggled figures pacing either along the beach or through tall grasses, peering at the ground. The three carry large black garbage bags. Occasionally one of them will bend down and pick something up and stuff it into the bag. Even from this distance, I can tell that what they have picked up is the body of a bird. I can also tell that their bags are bulging.

The King of All Terns

Rat Island is a parenthesis-shaped patch of land perhaps a thousand feet off the shore of Fort Flagler State Park, on the Olympic Peninsula. It is small, being less than 3,000 feet from top to bottom and 400 feet across at its widest point. I have not been able to find out how it got its name; presumably rats were involved.

A Caspian tern flying above water with a fish in it’s bill.

Adult Caspian terns can be up to two feet long, with a wingspan of nearly five feet. Photo: Eric Ellingson (CC BY-NC-ND 2.0)

Whatever the case, what distinguishes Rat Island now is that it hosts a large colony of Caspian terns. With a black cap, white body, and bright red bill, a Caspian tern cuts such a large and striking figure that biologists used to call it The King of All Terns. Adults can be up to two feet long, with a wingspan of nearly five feet. They might live for twenty years.

Caspian terns occur all over the world, but in the Pacific Northwest their presence might best be described as complicated. Here, although they still number in the thousands, their population has declined markedly in recent years. This is due in part to human management actions. Terns are innately itinerant; their colonies might pop up and then disappear in a year or two or ten. So it was that in the late 1990s, Caspian terns formed a new colony near the mouth of the Columbia River, at a place called Rice Island. They were drawn there by juvenile salmon, many from hatcheries, which swept past the island in droves as they migrated out to sea. The terns happily gorged themselves, and the colony was soon one of the largest in the world.

For state and federal agencies that were pouring hundreds of millions of dollars into salmon recovery on the Columbia River, the terns were a scourge. Caspian terns are protected as a species so managers could not just shoot them outright like they do other nuisances, but they could haze the birds in other ways. Different agencies showed admirable creativity, trying to drive the terns off: with bulldozers, with fences, with strings of flags, with humans. For this and other reasons, the population in the lower Columbia duly shrank, as terns left to find places to breed where they might be more welcome.

Worst fears confirmed

It was thus generally thought to be a good thing when hundreds of Caspian terns arrived at Rat Island a couple of years ago and started to nest. The problem, for the terns at least, was that Rat Island is eminently accessible from Fort Flagler. Last year, area kayakers drawn by the loud avian spectacle would paddle in, haul out on the beach, and walk into the colony; during especially low tides, visitors to the state park could wade over to the island. Some of them brought their dogs. Terns are skittish. If disturbed, they take to the air and scream at intruders. When they did that at Rat Island—and they did it often, between the kayakers and the walkers and the dogs—the gulls that also live on the island ate as many tern eggs and tern chicks as they could.

Many birds in flight above a narrow strip of beach with water on three sides and land in the far distance and gray skies above.

If disturbed by visitors to Rat Island, Caspian terns take flight (seen here flying among gulls). Photo: Katie Haman/WDFW

“People just didn’t know any better,” says Steve Hampton, the Conservation Chair at Admiralty Audubon, “and the terns paid for it.” By the time the nesting season ended last summer, a colony of more than five hundred pairs had produced a grand total of eleven chicks that survived long enough to fledge, or leave the nest. “It was awful,” Hampton says. “We decided that for this year we needed to have protection for them.”

From this was born the Fort Flagler docent program. Its purpose was to station volunteers on the mainland and educate visitors about the life across the spit at Rat Island, while also dissuading in-person visits. Kayakers were also encouraged to bob in the waters off the island but not land on it.

Breeding season is supposed to be a time of new life, of promise. Instead, at Rat Island, biologists were confronted with nothing but mortality and sickness, and suffering birds.

So it happened that one such kayaker, Sam Kaviar, was leading a tour near Rat Island last July when he saw a Caspian tern lying dead on the beach. He texted Hampton about it. One dead tern in a colony of over a thousand isn’t a big deal, Hampton thought when he read the text. But the next day Kaviar saw another dead tern. Later, he kayaked around the island and saw many dead terns, and others acting sluggish and sick.

Scott Pearson, a biologist with WDFW, happened to be working near Rat Island, and he boated by to collect some of the dead terns. He took them to Katie Haman, a wildlife veterinarian also with WDFW. She had the bodies tested for highly pathogenic avian flu, or HPAI. When the results came back, everyone’s worst fears were confirmed: the dead birds had tested positive. It was the first known outbreak of HPAI in Washington in the marine environment. (Several hundred snow geese died in the Skagit Valley the previous winter, and there have been cases in raptors and domestic poultry.)

Over the next few weeks, HPAI laid waste to the Rat Island tern colony. More than 1,600 terns—both adults and chicks—died. Officials in Oregon and southwestern Washington also confirmed an outbreak of HPAI among the remaining tern colonies in the lower Columbia River. Between Rat Island, the lower Columbia River, and points between, thousands of terns had died by the time the breeding season neared its close in September.

The link to poultry farms

Avian influenza is everywhere, all the time. Many viruses from a particular family cause it; H5N1 is merely the one that happens to be in the public eye at the moment. Scientists classify the different types of avian flus by their hemagglutinin proteins and neuraminidase proteins—the H and N, respectively. Since there are sixteen versions of the H protein and nine of the N proteins, H5N1, then, means the strain has the fifth H protein and the first N protein.

Avian flu types are further separated into two classes based on their virulence, or pathogenicity. Given that the bulk of birds that come down with avian flu tend to be domestic poultry, virulence is defined in chicken-centric terms. A bird infected with low pathogenic avian flu might show symptoms of mild disease and have slightly lower egg production, for example. Highly pathogenic avian flu, on the other hand, might kill 90% or even 100% of affected animals.

As a type, H5N1 is not new; rather, it has been circulating in birds for nearly thirty years. It was first detected at poultry farms in Guangdong, China, in 1996. It confined itself to Asia until early 2006, when it was subsequently found in poultry in Africa and Europe. It was thought to travel by way of migrating waterfowl, in whom it occurs naturally. Millions of domestic chickens, ducks, and turkeys have since died from H5N1, or been culled to prevent its spread.

The nature of H5N1 changed profoundly in the fall of 2020. A strain circulating among poultry swapped some genes with a strain circulating among wild birds, somehow producing a new, more highly pathogenic strain that was especially lethal to seabirds. Reports emerged from Europe of seabirds dying by the dozens, then thousands: great skuas and northern gannets at colonies in northern Scotland, several species of terns in the North Sea and Waddell Sea, razorbills, black-legged kittiwakes. In some places entire colonies were wiped out in a matter of weeks. The virus traveled well. In South Africa, hundreds of critically endangered African penguins died, as well as more than 20,000 cape cormorants. None of these species had been anywhere near a poultry farm.

By the end of 2021, this deadly new strain of H5N1 had reached North America. It spread rapidly, leaving a trail of similarly decimated seabird colonies and populations: northern gannets in Newfoundland, common eider ducks in St. Lawrence. This flu’s reach was long. Migrating snow geese died in Colorado. Hundreds of bald eagles around the country died, perhaps due to scavenging infected animals. In California, twenty California condors died, or 7% of the global population. The virus reached South America in late 2022, and began to race south from Peru like a fire, killing as it went: Humboldt penguins, guanay cormorants, black-necked swans, Andean geese, royal terns. Tens of thousands of Peruvian pelicans and Peruvian boobies died in rolling outbreaks.

The scale of death was unprecedented and hard to comprehend, much less stomach. All the more so because studies have suggested that as the number of poultry operations has increased in recent years, so, too, has the number of avian flu outbreaks in general. More chicken farms means more chances for avian flus to fester and spread, sometimes widely. Millions of animals dying all over the world in part so we can have buffalo wings and cheap eggs.

A grim task

Norris pilots the boat to the shore, and I hop out and scramble onto the beach. He hands me some surgical gloves and tapes them around the sleeves of my Tyvek suit, and then gives me my own large garbage bag. With that I leave to go find Haman, who is leading the effort today.

For a place that has just been visited by the specter of death, Rat Island is still quite lively with birds. Dozens if not hundreds of gulls are on the beach or in the surf, calling incessantly in the way gulls do. I can even hear a few Caspian terns, too. Did they get infected with avian flu and survive? Did they somehow never catch it? But there are other, more immediate questions. I approach the closest Tyvek suit. “Are you Katie?” I ask. It’s hard to tell folks apart given all the protective gear.

“She’s down there,” the Tyvek person says in a muffled voice. They wave off toward Rat Island’s westernmost shore. I tromp off and before long see someone wearing a bright orange life vest and mask, and a ballcap under their Tyvek hood.

“Katie?” I ask.

“Hey!” Haman says. She seems to be in reasonable spirits, all things considered. It wasn’t always so. After those first terns were confirmed to have HPAI, Haman and Pearson instituted a protocol to come out and count all the carcasses they could find to get a sense of the outbreak’s scale. But to be at a colony full of dead and dying birds was gut-wrenching. No one knew how to process what they were seeing, to say nothing of their own emotional responses to it. A breeding season is supposed to be a time of new life, of promise. Instead, at Rat Island, biologists were confronted with mortality, sickness, and suffering birds.

Embedded within the larger tragedy were dozens of smaller ones. Terns build only the most rudimentary of nests, usually just a scrape in the dirt. All around Haman were scrapes with one, two, or three eggs exposed to the elements, the birds that would have cared for them having succumbed. One adult had died while incubating its eggs; underneath its still-warm body, its chicks were hatching. Other orphaned chicks wandered the colony, begging for food from adults sprawled dead on the sand. All of them would starve or get eaten by gulls. “That was heartbreaking to see,” Haman says. “It just hit you really hard sometimes.” But she knew, too, that it was good she was here, to witness what was happening, and then to be able to talk about it. She is a wildlife vet, and wildlife vets are trained to deal with mortality; wildlife biologists aren’t necessarily. “The outbreak brought this conversation of the emotional impact on people out to the front,” she says. “Yes, it sucks, but it’s also good that we can have these conversations.”

A newly hatched fuzzy chick sitting on sand next to the spotted shell it hatched from.

Newly hatched Caspian terns are vulnerable to predation by gulls as well as avian flu. Photo: Katie Haman/WDFW

Now she gives me instructions: I’m to walk through a 50-meter swath in the center of the island, collecting bird carcasses that aren’t too decomposed while keeping a count in my head: of species (Caspian tern or gull), of age (adult or chick), of state (old carcass or new).

I start down my swath. Not to put too fine a point on it, but handling dead birds in the midst of an HPAI outbreak is an energizing experience. The feeling of being in the presence of the virus, of knowing it is on the ground, in the dust and sand, in the air, on the bird’s bodies. My senses buzz in ways they do not normally. (“To be around all this death,” Haman had emphasized, “is not normal, and it won’t feel like it.”) I can smell things through my mask, and I normally think of these scents as pleasant—the marine air, a tang I associate with seabirds. Now I am reminded that molecules of various sorts and sizes are breezing right through the N95 mesh. My glasses slide down my nose. I don’t dare touch them. (As another wildlife vet had said to me, “You know your eyes are a mucus membrane, right?”) I’ve just stuffed a dead gull chick into my garbage bag, after all, so who knows what’s on my gloves? Except that I fear I do know.

But we must collect the bodies. HPAI spreads through fluids—fecal, nasal—and a rotting seabird is nothing if not a decomposing bag of noxious fluids. The benefits of carcass removal are debated; some researchers think it makes little difference, while others point out that doing so prevents scavengers from eating infected bodies and getting HPAI themselves. So I pick up dead terns and gulls. As I do, a macabre, sing-songy tune floats through my mind, repeated over and over, the numbers updating as bodies go into my garbage bag:

  • Three old adult gulls
  • One fresh adult gull
  • Five fresh gull chicks
  • Six old gull chicks
  • Two old adult terns
  • Two tern chicks

After an hour or so, Haman determines that we have all covered most of the island. I lug my bag over and heft it into the inflatable, where Norris is penning a tally on a cardboard box. I count the tick marks of adult gulls, gull chicks, adult terns, tern chicks. The total is 147 bodies. Not all of these birds necessarily died of avian flu, I know, but I also remember Norris’ earlier observation when he was ferrying me over: This has been a quiet day.

Here in Washington, NOAA announced in early September that three harbor seals had been found stranded on Marrowstone Island, near Rat Island. They tested positive for HPAI—the first such infections of marine mammals, not only in Puget Sound, but also on the west coast of the U.S.

Transmission to humans

Other menacing and suggestive parallels lurk within the current outbreak of H5N1. In the subtext both at Rat Island and elsewhere the virus rages is the fear a strain of H5N1 could manifest that can more easily infect humans, leading to more efficient human-to-human transmission. To date, human cases of H5N1 are few and far between; most have been traced to someone working closely with sickened poultry. Even so, the mortality rate for H5N1 in humans is over 50%; and we are still living with the aftereffects of another disease that may have jumped from animals to humans.

For her part, Haman worries a lot—for the birds, for us. “I just don’t think people are taking this seriously enough,” she says. She is not alone. In an op-ed piece in the New York Times subtly titled, “An Even Deadlier Pandemic Could Soon Be Here,” Zeynep Tufecki argued that we ignore H5N1 at our collective peril. “The world needs to act now, before H5N1 has any chance of becoming a devastating pandemic,” she wrote. “We have many of the tools that are needed, including vaccines. What’s missing is a sense of urgency and immediate action.”

Already there are signs H5N1 is evolving to affect mammals more readily. In South America, thousands of sea lions have contracted it and died. Here in Washington, NOAA announced in early September that three harbor seals had been found stranded on Marrowstone Island, near Rat Island. They tested positive for HPAI—the first such infections of marine mammals, not only in Puget Sound, but also on the west coast of the U.S. “The discovery of HPAI H5N1 in seals brings to light the potential for cross-species transmission and highlights the complexity of managing infectious diseases in wildlife populations,” said Kristin Wilkinson, NOAA Fisheries’ Regional Stranding and Entanglement Coordinator, in a news release.

In all of this panicked discourse, the conservation implications for seabirds sometimes get drowned out. For some, like the northern gannets in Canada and Europe, the numbers of dead are significant, but will likely not threaten the species’ survival prospects. For others, like Humboldt or African penguins, or Caspian terns in the Pacific Northwest, the number of animals killed constitutes a large percentage of the existing population. Their future is less certain. “We lost more than a thousand adults in the region,” Haman says. “That could take years to replace.”

Another concern is this strain of H5N1 could simply wash around the world in successive waves, flaring up seasonally and hemispherically when colonial birds gather to breed. With this in mind, one question for Haman at Rat Island is why HPAI hit the terns so hard but seems for the most part to have spared the gulls. Next spring, she plans to come out and do blood tests on both terns and gulls. She wonders if the latter might be an asymptomatic reservoir for the disease, perhaps due to a previous exposure to a strain of low pathogenic avian flu, which may have protected them from HPAI. She also wants to do blood tests on any Caspian terns that try to breed here, to determine if they survived an infection or were somehow not exposed. All of this is contingent, of course, on there being some Caspian terns here.

One last look

After I have stowed my bag in the boat, Norris makes ready to go. Before we hop in, though, Haman wants to check out a flock of birds loitering on the beach. “I just want to see if any are showing, you know, signs,” she says. She and I trudge over to Rat Island’s eastern shore, which faces Fort Flagler. The afternoon is bright and sunny and cheerful. Across the water at the state park, kids are swinging at the playground, going up and down the slide, flying kites. I can hear their happy shouts. Do they have any idea what is happening on this late summer day less than half a mile from them? Is it better that they don’t seem to?

More immediately in front of us, a hundred or so gulls are carrying on. Near the flock’s edge, I can see, are a few Caspian terns, too. Not just adults, either, but adults and their nearly-grown fledglings. A quick count: there must be at least six or seven fledglings. I ask Haman if she has any idea how many tern chicks fledged this year. She says somewhere between twenty-five or one hundred. Hearing this, I think of what Hampton had said, that last year only eleven chicks fledged from the colony. That was due to human harassment and indifference. This year, even after the ravages of avian flu, the colony has managed to produce somewhere between two to ten times as many chicks.

There is probably a comment in that: About the relative threat people pose to birds versus the threat a world-sweeping virus poses. Before I can meditate on that, however, the scene modulates to a minor key. When Haman scans the small crowd of terns, she spies one fledgling whose wings droop, its wingtips brushing the sand. Two others are lying in repose on the beach in a suggestive way. We walk towards them to see what they do, how close we can approach. (An enfeebled bird might be so weak that you can walk right to it and pick it up.) All the gulls and terns leap to the air; and the three fledglings fly away, too, but not as quickly as the other birds.

In her Tyvek suit, Haman deflates a little. “We could try to catch them,” she says, but before she has even finished that sentence we know that such an attempt would be pointless. To try to catch a flying bird by hand—even a sick one—would end only in farce. The fledglings are strong enough, for now, to flee from us; but probably not strong enough to live for much longer.

We watch them land near their parents, and I tell myself that perhaps they will be okay. Perhaps they are not sick, but just tired. Perhaps, furthermore, their parents will come back to Rat Island next year. Perhaps they will breed with thousands of other Caspian terns, and perhaps all their chicks will grow strong, and perhaps the colony will thrive for years to come. I would like to think so, to believe in a future of perhaps. But it is not up to me.

About the author: Eric Wagner is a staff writer at the Puget Sound Institute. His writing has appeared in Smithsonian, Orion, The Atlantic, and High Country News, among other places. He is the author of “Penguins in the Desert” and co-author of “Once and Future River: Reclaiming the Duwamish.” His most recent book is “After the Blast: The Ecological recovery of Mount St. Helens,” published in 2020 by University of Washington Press. He holds a Ph.D. in Biology from the University of Washington.

Creative Commons License
Story text available under a Creative Commons Attribution-NonCommercial-NoDerivs license: CC BY-NC-ND 4.0.