Even after 44 years, preparing for the field season to study Black Guillemots on Cooper Island is a time of excitement and anticipation as I gather the gear and supplies needed to survive and conduct research for three months on a remote Arctic island. This year the excitement was tempered with a high level of anxiety given last summer’s disastrous breeding season. While the size of the colony has been decreasing since the 1990s, as the guillemots’ sea ice habitat has steadily dwindled, the 2018 breeding season was unique in that 1) the overwinter mortality of breeding birds was three times the long-term average, 2) one third of the returning pairs failed to lay eggs and 3) half of the pairs that did lay eggs abandoned them soon after laying. The result was a colony that in August had only 25 functioning breeding pairs – something hard to observe and process when one has a vivid memory of a 200+ pair colony in the late 1980s.
Back in Seattle I was still processing the data and the implications of the 2018 field season when the U.N. issued a report about the pace of global climate change with a separate report on the Arctic saying a 2-5oC temperature increase was locked in for the region even with major reductions in fossil fuel emissions. While the reports had the positive effect of finally having the media and public focus on the trends in and causes of climate change, along with my findings in 2018 they affected the way I viewed my long-term study. Documenting the pace and magnitude of biological changes in the Arctic seemed all the more important.
I headed north to Utqiagvik (Barrow) in early June knowing that the guillemots had experienced another year with little sea ice in the traditional wintering area in the Bering Sea and that the Arctic Ocean off northern Alaska adjacent to their breeding colony had unprecedently low sea ice extent for early summer. Conditions like those are bound to pose major difficulties for the Cooper Island Black Guillemots. While I start the season with concern for the long-term trajectory of the colony, I see the 2019 field season as a unique opportunity to document the resilience and adaptability of one of the Arctic’s sea-ice obligate seabirds. I look forward to providing you updates as the breeding season progresses on this website, Proteus, our Twitter feed, and the Friends of Cooper Island Facebook page.
Graduate student Drew Sauve recently returned from Cooper Island. He describes his collaboration with George in this guest post.
The Black Guillemots on Cooper Island are one of many wild populations that are responding to climate change by changing when they lay their eggs. These Arctic seabirds want to lay their eggs as soon as the winter snow melts and spring begins, because their breeding season—from first access to a nest cavity to departure of chicks—is 80 days, an exceptionally long breeding period for a bird. Parent guillemots have to have their young ready to fly off to sea before fall snow accumulation begins to block entrances to nest cavities. In recent years, with sea ice retreating offshore in late summer, early breeding has the benefit of being able to provision young when the preferred prey of Arctic Cod is still readily available.
While there are decades of data that show spring snowmelt is occurring earlier in northern Alaska and, allowing guillemots to lay their eggs earlier, my research is focused on whether Black Guillemots are evolving to lay their eggs earlier.
George has created a detailed banding dataset, where every parent has a numbered metal band, and a unique colour band combination; all of their nestlings are banded before fledging. Using this data set, I can construct family trees for the birds breeding on the island. Family trees or pedigrees are often used in studies of human health or livestock breeding. In the rare case where we have long-term pedigrees in wild populations, geneticists can use them to determine genetic variation in a trait—in this case, when birds lay their eggs.
The amount of genetic variation or the potential for genetic change in a key trait like egg-laying date could determine whether a population will be able to adapt to climate change.
The analyses we do with a pedigree are similar to what a farmer might do when trying to select cows that produce more milk. Some cows and their families might produce more milk, so the farmer would select those cows when breeding their stock. Instead of cow families that produce lots of milk, I tried to find guillemot families that laid their eggs earlier than others in response to snowmelt. However, instead of a farmer selecting cows I wanted to see if climate change was selecting for earlier breeding guillemots.
Ultimately, there were no family groups that tended to lay earlier than others. Using my farmer example again, this would be like trying to select a cow with high milk output when all the families of cows produced the same amount of milk. The farmer would be unable to improve their herd because all the cows are the same with regards to milk production.
What this means on Cooper Island is that Black Guillemots are unlikely to evolve earlier laying dates to match warmer temperatures and the change in laying-date we’ve observed so far is not because of evolution. Rather individual birds are behaviorally adjusting their laying date due to changes in snowmelt.
Unfortunately, this behavioural response to snowmelt doesn’t seem to be enough of a response as the birds are still struggling to raise offspring in the warming Arctic.
The Cooper Island data demonstrate the power of long-term, detailed data collection. Just as George did not intend to study climate change when he started the study in 1975, I also do not think he intended on collecting data that one day would be useful for building a pedigree with multiple generations of Black Guillemots, but he did just that.
The value of long-term datasets might not always be apparent when starting the study, but much of our understanding of evolution, behavior, ecology, and responses to climate change come from research that span decades. I suspect that the Cooper Island dataset and others like it will continue to be valuable in the future.
Science writer Jenny Woodman of Proteus writes about Cooper Island research and the current field season.
George Divoky frets–with good reason. In 2016, CNN Correspondent John D. Sutter called him the man who is watching the world melt. The description is as distressing as it is apt.
George sends us regular dispatches from a small field camp on Cooper Island, about 25 miles east of Utqiaġvik, where he has studied a colony of nesting Mandt’s Black Guillemots for the last 44 years. Since his work began in 1975, the research has morphed into one of the longest-running studies of seabirds, sea ice, and climate change.
Guillemots look like small penguins headed off to a fancy party replete with ice sculptures and all-night dancing. Unlike other seabirds that migrate out of the region seasonally, they live out over the frigid waters year-round, only returning to land to breed and fledge their young–this makes them an excellent indicator of how climate change is impacting the Arctic.
Weather delayed the start of this research season in early June. While warm temperatures in the Arctic have made headlines in recent months, unusually late snow and ice kept the guillemots from reaching their nesting boxes until mid-June; the first egg was laid on June 24.
His communications are tinged with an effort to buoy spirits–I’m guessing his own more so than ours. This week, the bad news came first: a 29-year-old female died. He wrote that she had been banded during the first George Bush administration. (While many humans rely on a simple Gregorian calendar, George’s memories appear to be synchronized according to a timeline rooted firmly in geopolitics.)
Bad news was followed with happy; two siblings from the 2014 cohort returned and recruited partners for breeding.
Otherwise, it’s been a stormy week on the island. On July 20, he wrote that the wind was finally dying down. A bad week for the infrastructure, the camp’s weather station was blown over and part of the heavy-duty WeatherPort tarp separated from the frame, which caused a number of things to get wet. On Wednesday he saw record high rainfall for that date.
Egg laying hit an all-time low this year, with fewer breeding pairs than any previous year.
He’s asking questions about how changing ice conditions will impact these seabirds – his seabirds. In his most recent field report, he spoke at length about the relationship between the guillemots and nearshore sea ice. The location of the sea ice impacts how far parents will have to fly to access suitable prey for their chicks. Increased travel time means greater energy expended by parents – for seabirds that live predominantly out in open waters, it’s all about balancing resources and energy. The presence or absence of sea ice combined with the temperature of the ocean waters impacts the availability of Arctic Cod, the small nutritious fish the guillemots prefer.
George hopes the slowly departing nearshore sea ice will keep ideal prey in foraging range for the seabirds. He wrote, the cod is “urgently needed for the colony to reduce its current population decline.”
David Douglas is a research wildlife biologist for United States Geological Survey (USGS) Alaska Science Center; he and George are frequent collaborators. This week he emailed the MODIS images displayed above and wrote that Cooper Island was pretty well surrounded until July 16 when the persistent ice immediately around the island broke up and melted.
Studies like George’s will help scientists to better understand the ramifications of long-term warming and less sea ice for wildlife in the region. Impacts to wildlife will directly affect the lives of the people who depend on subsistence fishing and hunting for survival.
Warming Arctic conditions have persisted with 2018 reaching record lows for sea ice extent, according to a report published by NOAA and University of Alaska Fairbanks’s International Arctic Research Center.
Late ice formation and early retreat in the Chukchi and Bering Seas impacted local communities by making travel for subsistence hunting and fishing dangerous and, at times, impossible. Storm damage and erosion was worsened by exposed shorelines, left unprotected by a lack of sea ice. Island villages and coastal communities experienced flooding and property damage as well. You can read more about the storm impacts here and here.
The report attributes late and minimal ice coverage to warmer temperatures, particularly over the last four years. Increased temperatures combined with stronger storms helped break up weaker ice.
In 2018, there was less sea ice in the Bering Sea than any year since 1850, when commercial whalers began recording this data. Experts agree, loss of sea ice is a result of climate change. Continued warming creates a feedback loop where warming temperatures melt ice; without a reflective snow and ice covering, the ocean absorbs more of the sun’s warming rays and temperatures continue to rise.
As for future winters, what can people expect to see if warming continues at current rates?
“Communities need to prepare for more winters with low sea ice and stormy conditions. Although not every winter will be like this one,” concludes the report, “there will likely be similar winters in the future. Ice formation will likely remain low if warm water temperatures in the Bering Sea continue.”
And for George’s seabirds? How many birds will successfully fledge this year? How many will return next?