Keywords: Species and food webs, Birds, Marine habitat, Nearshore habitat, Aquatic reserves, Oil spills, Vital Signs, Salish Sea, Marine birds, Implementation Strategies, Disease, Monitoring

Scientists are still trying to understand what caused the deaths of thousands of rhinoceros auklets in the Salish Sea in 2016. Some studies point to disease as a central factor in that incident and potentially other large seabird die-offs along the coast. That is prompting a deeper look at what makes these birds sick, and how local populations are faring. We followed a group of researchers as they gave a health checkup to a breeding colony of rhinoceros auklets on Protection Island.


Picking the best spot to catch a rhinoceros auklet (or, ideally, several of them) can seem as much a matter of art as of science. When the auklets fly in from the Strait of Juan de Fuca in a few hours to return to their burrows under cover of darkness, are they more likely to zip over the short rise here or the one over there? And if the net is at the crest of this rise, rather than just below it, will the auklets be able to see it well enough to avoid it? Place the net too low on the slope, though, and the auklets are liable just to fly over it. So: much to mull.

“This looks like a good spot,” says Scott Pearson, a biologist with the Washington Department of Fish and Wildlife. It is nearly dusk, and Pearson is standing waist-deep in grass on the south side of Protection Island, a national wildlife refuge a mile or so off the northern coast of the Olympic Peninsula. A few yards from him, Peter Hodum, a biologist from the University of Puget Sound, is looking between the water, from which the auklets will come, and the interior of the island, where they will go. “Yeah,” he says. “It seems like they’d be kind of funneled up this way.”

A hillside on Protection Island dotted with auklet burrow entrances. Photo: Eric Wagner

A hillside on Protection Island dotted with auklet burrow entrances. Photo: Eric Wagner

The two set up what are known as mist nets —  named for their fine mesh, which is hard for birds to see in low light — jabbing tall poles into the ground and carefully threading the net’s end loops onto them. Once fully opened, the nets are about forty feet long and six or seven feet tall, with several baggy shelves that create a loose pocket for the birds to truss themselves in. But as Pearson opens them to their full height, several large holes and tears appear. “These have… seen some action,” he says, and chuckles before collapsing the nets. He and Hodum will come back later with the rest of their crew, which includes two wildlife veterinarians, and then the trapping will begin in earnest. After all, like most wildlife, auklets can be reluctant patients when it comes to getting a checkup.

A question of health

Rhinoceros auklets are similar in size and girth to a small pigeon, with sturdy bodies and stubby wings. When breeding they sport white plumes above their eyes and across their cheeks, and grow a little stub of horn at the base of their bill. Otherwise, their plumage is a study of grays — dark above, light beneath. With other seabirds, they occupy key positions in the Salish Sea food web, and are considered to be one of the vital signs of the ecosystem’s overall health.

Alt text: Adult rhinoceros auklet (Cerorhinca monocerata). Photo: Frostnip https://flic.kr/p/

Adult breeding rhinoceros auklet (Cerorhinca monocerata). Photo: Frostnip (CC BY-NC 2.0)

But what of the seabirds’ own health? The status of that is a little less clear. “There are a lot of people looking at the abundance of seabirds in the Salish Sea,” says Greg Frankfurter, a wildlife veterinarian with the Wildlife Health Center at the University of California-Davis. “But no one’s really looked at the role disease might play in process.” On top of that, disease itself is a big, generous term. “People mostly think of things like avian influenza, or massive bacterial infections, but there can be a lot of other things,” Frankfurter says. “There is not a wild animal out there that doesn’t have a parasite burden, from gastrointestinal parasites to ectoparasites, and blood-borne parasites are more common in seabirds than marine mammals.”

Mounting evidence, however, shows that warmer seas are sicker seas. As Drew Harvell, a marine ecologist from Cornell University, wrote in her recent book Ocean Outbreak, humans have “created a perfect storm of outbreak conditions in the ocean.” While birds are at risk, they are hardly alone. A 2015 study in the Proceedings of National Academies of Science found that the frequency of mass mortality events was increasing in everything from mammals to reptiles to amphibians to fish to invertebrates. “Across all animal taxa,” the authors wrote, “causes of [mass mortality events] were most often associated with disease and were attributed to viral (44.5%), bacterial (18.3%), and fungal infections (12.2%).” This was greater even than what the authors called “human perturbation,” which usually came in the form of environmental contamination, such as an oil spill.

Waiting for the birds

By 8:30 p.m. or so, Pearson and Hodum lead the group out to the capture site. Also along are Tom Good, a NOAA biologist; Sue Thomas, the refuge biologist from the U.S. Fish and Wildlife Service; Lilli Patton, one of Hodum’s students at the University of Puget Sound; and the two vets, Katherine Haman, from WDFW, and Frankfurter, who is up from California. It is a large group, but Pearson is hoping all those hands will be necessary, and filled with auklets.

The sun is sinking and the wind is strong when the group reaches the nets. “Good night to be bundled up,” someone says. “Too bad it’s July,” someone else responds, but it is hard to tell who is who under all the fleece hats.

Pearson and Hodum open the nets and settle into the grass a few feet uphill, so they can quickly extract any ensnared auklets. (“You want to be quick about it for the bird’s sake,” Pearson had said.) Haman and Frankfurter set up their equipment back on the road so they can process whatever auklets are caught. Everyone else spreads out along the hillside. They will try to catch by hand those auklets that evade the nets but still land in the area.

The sun has set for good now. Pearson and Hodum do a final check of the nets, which billow like spiderwebs, while Good, Thomas, and Patton move about by headlamp. Little points of light dance about the hillside as they get in position and make themselves comfortable. For a moment everyone’s lights are stationary, like stars in a grounded constellation, and then each winks out one by one, and there is just the dark, and the wind blowing through the tall, dry grass.

Rhinoceros auket with sand lances. Photo by Peter Hodum.

A rhinoceros auklet with sand lances. Photo: Peter Hodum

Implications for humans

Seabird health and their disease burden can have far-reaching implications, not only for the birds themselves, but also, as Frankfurter notes, for humans. The past decade or more has seen a steady parade of papers suggesting possible pathways for pathogens between birds and people. In 2008, for example, researchers in Portugal reported finding antibiotic-resistant strains of E. coli in gull feces collected on public beaches. In 2011, a French researcher reported similar results from Miami Beach in Florida. In 2016, researchers in Lithuania and Argentina both reported antibiotic-resistant strains of E. coli in herring gulls and kelp gulls, respectively, both of which are common and widespread. (The researchers suspected the gulls were exposed to the bacteria by eating garbage that contained either sewage or medical waste.) And just a few months ago, Australian researchers found antimicrobial-resistant bacteria in the feces of silver gulls, which are, they wrote somewhat ominously, “a gregarious avian wildlife species that is a common inhabitant of coastal areas with high levels of human contact.”

To date, though, no one has really studied the prevalence of disease among the Salish Sea’s seabirds. But there have been worrisome signs that disease may have a significant impact on their well-being. Near the end of the marine heat wave known colloquially as The Blob, rhinoceros auklets in the Strait of Juan de Fuca in the summer of 2016 experienced a mass mortality event. Hundreds of dead auklets washed up on area beaches; all told, thousands are thought to have died.

Subsequent necropsies of a few of their bodies suggested the auklets had been food-stressed, while also showing signs of a viral infection. Untangling which was cause and which was correlation has been tricky. Did the auklets get sick because they were already thin? Or were they thin because they had already gotten sick? It was, as Bob Friel of the SeaDoc Society would later call it, the “riddle of the rhinos.”

In the nets

You hear the auklets before you see them, the steady quick whirr of their wings as first one and then two more zip in overhead. It is a little after 9:30 p.m., and they fly low above the grass so as not to present a target to any waiting bald eagles. Landing for them is a haphazard affair; there is a thrashing sound as they smack into the grass, and then a dry shuffle as they scramble through the tussocks to the mouths of their burrows, which might be several feet deep. Crosswise in their bills they carry up to twenty small fish for their single chicks, which are several weeks old now; both parents will feed the chick each night.

Suddenly a headlamp — Hodum’s — flashes on near the nets. It illuminates a twitching lump: An auklet dangling in the mesh and struggling to free itself. Hodum rushes over and secures the bird with one hand while delicately extricating it with the other. He then hustles it to Frankfurter and Haman, who are seated next to a large cooler — their workstation. As he does, two more auklets ensnare themselves; Pearson hops up and gets busy removing them.

For those people arrayed about the hillside, pursuit and capture is a bit more frenetic. When they hear an auklet land near them — five feet away, ten feet away — they bound up and turn on their headlamp, trying to illuminate it. If perfectly caught in a beam, the auklet might freeze, but more often than not it scampers away, obliging a brief but intense chase through the grasses. The auklet bobs and feints, but once a person claps a hand over it, it yields. (Whoever catches the bird scoops up the fish to analyze later.)

Veterinarians Greg Frankfurter, UC Davis and Katie Haman, WDFW take a blood sample from the wing of a rhinoceros auklet. Photo: Peter Hodrum

Veterinarians Greg Frankfurter, UC Davis and Katie Haman, WDFW take a blood sample from the wing of a rhinoceros auklet. Photo: Peter Hodrum

At the workstation, Patton and Thomas arrive holding auklets, with Good bringing one up behind them. The birds scratch with their sharp toe claws and bite with their strong bills, and when that does not work they moan their distress. An assembly line forms. Pearson measures auklets and bands them, and then passes them off to Frankfurter and Haman, who take a swab from their cloaca and draw a couple of drops of blood from a vein in the wing.

Back on the hillside, auklets are hitting the net with greater frequency. Hodum brings them over faster than Pearson, Frankfurter, and Haman can process them. There are eight of them now. The excess ones go into blue cloth bags until Pearson is ready for them. “I’m going as quick as I can,” he says, trying to reassure them, but the bags still jerk and twitch and moan.

Finding a baseline

Where Frankfurter’s needs are perhaps more generally investigative, Katie Haman’s have a more specific application: Oil spill response. “We want to establish some solid baselines with the assumption that there might be a massive oil spill in the area someday,” she says. “Having those baselines would help wildlife health officials respond in such an event.”

Initially, Haman’s project was aimed at marbled murrelets, but she and her coworkers later decided to switch to rhinoceros auklets in part because they are far more abundant. Her work with them will focus on acute phase proteins. Acute phase proteins, she says, are a component of the innate immune response; they increase or decrease in response to inflammation. Researchers working in the early 1900s first identified them as initial reactants to infectious diseases. Studies by Carolyn Cray at the University of Miami, with whom Haman is collaborating, have shown that they are good biomarkers whose levels correspond with infection, stress, trauma, or other symptoms; and in some species, they can serve as prognostic indicators of survival.

“The goal is to show that we can establish baselines,” Haman says. In the event of trauma, be it pathological or otherwise, the levels of those proteins increase detectably, enough so that they can establish a clinical variable. For although Protection Island is a wildlife refuge, sources of potential traumas surround it. Just across the border, near Vancouver, British Columbia, the Port of Vancouver is in the midst of building a second terminal. Combined with the eventual completion of the Kinder Morgan Trans Mountain pipeline promises a significant increase in area ship traffic.

Should there be an oil spill, wildlife health response officials could potentially triage birds based on their APP levels. The need for triage can be critical during such a catastrophe event, where hundreds, or even thousands, of alcids may strand. Already wildlife rehabilitation is an expensive enterprise, made more so by pouring scant resources into saving animals that are likely to die no matter how much help they receive. “A lot of times you’re completely overwhelmed with sick animals,” Haman says. “So it would be great to have a rapid screening test.”

Whatever Haman finds with rhinoceros auklets could also be applied to other species of general conservation concern, such as marbled murrelets or tufted puffins. “The general state of seabird disease in Salish Sea is not well known,” she says, laughing a little grimly. “Honestly, that’s what we’ve been saying for years. One of the biggest complaints of wildlife health is no one wants to do baseline work. But then we find ourselves in situations where a population is declining and we just don’t know about its general health, and that makes recovery efforts all the more difficult.”

Letting them go

At 11:30 p.m. or so, the action at the mist nets has died down. A few auklets buzz overhead from time to time, but they are bound for different parts of the colony. Some of these birds might also be non-breeders, coming in simply to prospect or socialize. They wander out in the open, their calls wafting over the slopes as they serenade one another: Waa-Waaaaa, Waa-Waaaaa.

Back at the workstation, Frankfurter and Haman are processing the night’s final auklet. The effort was largely a success, in that thirteen birds have been caught and bled. For his work Frankfurter had wanted thirty, but thirteen will do. “It gives us something to work with,” he will tell me later.

Haman takes blood from the auklet’s wing and smears it on a slide, then holds an alcohol swab to the withdrawal site. When the bleeding stops, she cradles the bird, which looks a little nonplussed but is otherwise none the worse for wear. “Who wants to let him go?” she asks. 

“I’ll take him,” Sue Thomas says. She carries the last auklet out to the slopes, and tosses him up into the darkness. The bird flails through the air and tumbles down into the grass, before righting itself and lifting off in a flurry of wings, vanishing into the night.

Postscript: A couple of months later, Pearson will get word that rhinoceros auklets are having another unusual mortality event, with dead rhinoceros auklets found on beaches from northern California to Cape Flattery, Washington. According to Pearson, the die-off appeared to have started in August; by early November it had peaked, or perhaps not yet peaked. The cause is as yet unknown.


About the author: Eric Wagner writes about science and the environment from his home in Seattle, where he lives with his wife and daughter. His writing has appeared in Smithsonian, Orion, and High Country News, among other places. His most recent book is Penguins in the Desert published by Oregon State University Press. He is currently writing a book about Mount St. Helens.