Tag: Cooper Island

Loss of Sea Ice Takes Its Toll on Seabirds

Post author By Jenny Woodman
Post date August 12, 2019

Three visitors to Cooper Island Arctic Observatory see firsthand how rapidly changes are taking place. — Pierre-Loup Jan, Katie Morrison, George Divoky, and Maria Coryell-Martin in August of 2019 on Cooper Island. Image Credit: George Divoky

The positive signs of colony size and breeding effort of the Black Guillemots on Cooper Island in June were too good to last.

After very high hatching success, the decreased ice and increased water temperatures took their toll as parents were unable to find prey in the warm, ice-free waters. Rapidly shifting ocean temperatures provided some days of good growth, but currently only one third of chicks are still alive. As the mortality was unfolding, we shared it with a reporter from the Washington Post for an article describing the impacts of climate change in Alaska in 2019.

The authors note that, “The early retreat of sea ice from the Bering and Chukchi seas has led to a jump in sea surface temperatures, altering weather patterns and upending the lives of residents who typically depend on the ice cover for hunting and fishing. It’s also affecting native species, including seals and seabirds.” In the article I describe the high rate of chick mortality from the loss of sea ice, which limits guillemots’ access to their preferred prey, Arctic cod.

Helping to monitor the changes that are rapidly occurring this summer are a Seattle science teacher, an expeditionary artist, and a French demographer. Pierre-Loup Jan, is a population dynamics modeler from the Centre d’étude biologique de Chizé, a local branch of the French National Centre for Scientific Research, analyzing the Cooper Island database as part of the Sentinels of Sea Ice (SENSEI) project lead by Christophe Barbraud and Yan Ropert-Coudert.

The SENSEI project aims at fighting against the reheating of the poles which have drastic consequences on the sea ice (decrease of the surface of the sea ice in Arctic and in contrario increase in Antarctica). Video Credit: BNP Paribas Foundation

On the island for the second time is Katie Morrison, board president for Friends of Cooper Island and an elementary school science educator in Seattle, WA. Maria Coryell-Martin, an expeditionary artist from Port Townsend, WA, is exploring the landscape and research of Cooper Island through watercolor sketches. Together, Katie and Maria are working on an interdisciplinary exhibit and educational materials.

Even in their short time on the island, they have witnessed dramatic changes and the impact of a rapidly melting Arctic.

This field report is part of an ongoing series titled Arctic Change centered around George Divoky’s 45th field season studying Black Guillemots, sea ice, and climate change on a remote Arctic island off the coast of Alaska. To donate and support Divoky’s work on Cooper Island, visit the Friends of Cooper Island website.

Read more

Alaska’s sweltering summer is ‘basically off the charts’ by Matthew Cappucci, Juliet Eilperin, Andrew Freedman, and Brady Dennis

SENSEI: 8 Animal Species to Understand Global Warming by BNP Paribas

Europe’s Heat Wave Moves North by National Snow and Ice Data Center (NSIDC)

Satellite Observations of Arctic Change Overview by NSIDC

Tags Arctic, Black Guillemots, Climate Change, Climate Data, Cooper Island, NSIDC, Sea ice

Documenting Arctic Change

Post author By Jenny Woodman
Post date July 19, 2019

Cooper Island has provided me with a place to conduct a long-term study of an Arctic seabird and also a place where I have been fortunate to establish some long-term friendships. In June 2001, photographer Joe McNally visited the island to obtain images to accompany the New York Times story Darcy Frey was writing about the Cooper Island research. Joe’s week on the island in 2001 started with him being sick in his tent for the first two days but, after he and I had spent a week walking through the guillemot colony and chatting back at camp, ended with a friendship that has lasted 18 years.

Joe McNally and George Divoky on Cooper Island in 2019, 18 years after McNally’s first visit to the island to document Arctic change. Image Credit: Joe McNally

While Darcy’s story and Joe’s photos were scheduled to appear in the autumn of 2001, events in mid-September altered that scheduling, as the Times and the rest of the media focused on stories about 9/11 for the remainder of the year. To have 2002 begin with a break from events of the fall of 2001, the New York Times Magazine ran the Cooper Island story the first Sunday of the new year with Joe’s picture of me standing on sea ice as the cover photo.

Over the past 18 years, whenever Joe and I have been able to meet, I told him I hoped he could return to Cooper Island someday to document how continuing warming has changed the Arctic since 2001. That all seemed like a pipe dream until recently when Joe arrived by boat from Utqiaġvik to spend a few days on the island to revisit the Black Guillemot colony and discuss my observations and thoughts about my 45 years of study.

Joe’s career in photography has taken him to many amazing places and his choosing to return to Cooper Island meant a great deal to me. This year’s visit came after almost four weeks alone on the island and the camaraderie of Joe and crew was an excellent way to end my solitude. Observing and documenting a melting Arctic can be disheartening but Joe’s desire to help me tell the Black Guillemot’s story – and the chance to renew our long-term friendship – raised my spirits as I approach the midpoint of this field season.

George Divoky’s Planet by Darcy Frey

Arctic Sea Ice Blog

Tags Arctic, Black Guillemots, Climate Change, Cooper Island, Sea ice, Seabirds

Arctic Change

Early Season Optimism as Guillemots Diligently Attend Eggs

Post author By Jenny Woodman
Post date July 10, 2019

Field camp cabin in remote Arctic Cooper Island. — Mandt’s Black Guillemots roosting on roof of Cooper Island cabin, which was added to the field camp in 2003 when polar bear encounters were on the rise. Image Credit: Mike Morrison

Polar bears caused me to get a cabin on Cooper Island in 2003. After a rapid retreat of sea ice in August 2002, bears trashed our tents, which required making a hasty departure from the island with the help of a North Slope Borough Search and Rescue helicopter. The first week of the 2019 field season found me again living in a tent as I cleaned up after a polar bear was able to remove the board covering the cabin door and rearrange much of the gear and supplies I store on the island overwinter. Damage was not major but making my 8- by 12-foot summer home habitable took time.

Polar bears are frequent visitors on the island, requiring a range of protective measures from bear fences to a small cabin added in 2011. Video Credit: George Divoky

Luckily the first week’s tedium of camp housekeeping was balanced with daily indications that the Black Guillemot’s 2019 breeding season would not be a repeat of last year, when colony size and productivity had major decreases related to the poor survival and breeding condition of adults. Of the 75 nest sites occupied last year, only 25 had pairs that incubated eggs. This year a similar number of nests are occupied but all of those have birds diligently attending eggs.

The reasons for the difference in the two years is not yet clear. Both breeding seasons were preceded by a previously unprecedented lack of sea ice in the Bering Sea wintering area. Geolocation data loggers I am retrieving from some of the birds will allow comparison of the overwinter movements and distribution for the two years and may provide an answer.

Another indication of the health of the colony in 2019 is the number of first-time breeders. Long-term annual mortality of established breeders is approximately ten percent, and a stable population requires enough new recruits each year to occupy the vacancies. Unlike many recent years, this year saw a substantial number of previously nonbreeding local birds (individuals fledged from Cooper Island) and immigrants occupying those vacancies and even pairing up with each other to breed in sites not occupied last summer – something that has been rare in the period of colony decline in recent decades.

Another major highlight of the first week of censusing was the sighting of a bird fledged in 2017, a year when the colony experienced large-scale nestling mortality. The season was documented by Hannah Waters in Audubon magazine. The two-year old bird sighted this year was raised in the nest featured in the Audubon cover image by Peter Mather; it shows a female parent about to enter a nest with a sculpin. The story emphasized how the colony’s survival in a melting Arctic would require a few individuals to be able to provision young from ice-free waters and for those young to return to breed. While the 2017 offspring sighted this year is not breeding, few birds breed earlier than three years of age, its return to Cooper combined with the other positive signs of colony health in 2019, provide reasons for some early season optimism.

Making Camp in the Arctic by George Divoky

Birders Don’t Need to Be Told That Catastrophic Climate Change Approaches by Hannah Waters

Disappearing Ice Means New Ways of Life for Arctic Birds by Hannah Waters

Tags Arctic, Black Guillemots, Climate Change, Cooper Island, polar bears, Sea ice, Seabirds

Arctic Change

45th Arctic Field Season Underway

Post author By Jenny Woodman
Post date June 27, 2019

A satellite image of Cooper Island from June 26, 2019. Image Credit: NASA

A satellite image of Cooper Island from June 26, 2019; George Divoky has spent the last 44 summers here, studying a colony of Mandt’s Black Guillemots. Image Credit: NASA

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 2-5^oC 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 Utqiaġvik (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.

NOAA’s Arctic Report Card: Update for 2018

Arctic Change: 2018 Cooper Island Field Season

Tags Black Guillemots, Climate Change, Cooper Island, Sea ice

Arctic Change

Back from the Wilderness

Post author By Jenny Woodman
Post date September 15, 2018

George Divoky at work in the Arctic. Image Credit: Mike Morrison

George and Thomas during 44th field season on Cooper Island. Imager Credit: Mike Morrison

George and Thomas tagging and releasing Black Guillemots. Image Credit: Mike Morrison

For the past four decades, my field seasons on Cooper Island studying Black Guillemots have always begun with high spirits and a feeling of optimism. Experiencing the 24 hours of daylight in early June while documenting the return of individual birds to the island and their nest sites is always uplifting – some of these seabirds have been returning to Cooper Island for decades. Then, the days begin to shorten as nighttime returns to the Arctic. After monitoring the colony’s breeding activity for over three months, the end of the field season in late August lacks the intensity of the start of the season, but until recently, provided the gratification of having a large number of nestlings depart the island – with the hope many will return in the coming years.

The end of my 2018 fieldwork was as atypical and unpredictable as the first part of the season. In June I saw the colony had experienced a major decline in breeding pairs due to unprecedented high overwinter mortality of adult birds and many of the birds that did return failed to either lay eggs or incubate the eggs they did lay.

After those initial indications that many of the adults were in poor condition in late June, I was surprised to find that the chicks had high survival in late July and August – unlike the widespread nestling mortality witnessed in 2017. Last year’s low breeding success, with the younger of the two nestlings dying in almost all nests, was due to an early and major retreat of the pack ice in the Beaufort Sea, making the guillemots’ preferred prey of Arctic Cod unavailable to foraging parents. This past summer’s sea ice retreat was later than last year and atypical in that, although much of the Beaufort was free of ice by late August, a large remnant of sea ice remained near the Alaskan coast keeping the waters near Cooper Island cold enough for Arctic Cod.

Screen Shot 2018-09-15 at 11.36.02 AM — A large remnant of sea ice helped keep Arctic Cod in the Black Guillemot’s foraging range this summer. Image Credit: Alaska Ocean Observing System

Our last two weeks on the island were busy. In addition to monitoring the growth and departure of the guillemot fledglings, we spent many hours capturing adult birds and outfitting them with light-sensitive geolocation and activity data loggers. The high mortality during the nonbreeding season of 2017-2018 shows that winter conditions affecting adult survival, rather than the success of the breeding season, may now play the major role in determining the fate of the Cooper Island colony. As part of the SENSEI project, we deployed over 30 data loggers on adults that will provide us with information on their movements, distribution and activities from this fall until they return to the Cooper Island colony next spring.

My field assistants, Thomas Leicester and Mike Morrison, and I did see individual variation in the ability of the guillemot parents to find cod in the ice-free but cold (<4 degrees Celsius) foraging area. While some chicks weighed over 300 grams in their third week in the nest, some nests had young with large variation in daily growth and weights remaining in the low to mid 200 gram range. While it was heartening to see nearly 40 guillemot nestlings fledge this year, due to the number of nonbreeding pairs and those that abandoned eggs, chick production per active nest was well below the one fledging per nest needed to sustain a stable population.

Screen Shot 2018-09-15 at 11.35.43 AM — Light-sensitive geolocation and activity data loggers help us learn where the Black Guillemots go during the winter. Image Credit: George Divoky

While I typically use my first week after the field season to slowly transition into an off-island existence, as I adjust to a life with running water, internet access and no polar bears, this year I traveled to Great Britain for the International Seabird Group Conference in Liverpool. I have always felt a kinship with British seabird researchers as my initial interest in conducting a long-term seabird study came from reading the books of Ronald Lockley, who in the early 20^th Century decided to live on an uninhabited British island where he could study seabirds.

After the conference I traveled to the Centre d’Etudes Biologiques de Chizé where I am collaborating with Christophe Barbraud and others who, as part of the SENSEI project, are analyzing the 44 years of demographic data obtained on Cooper Island.

In spite of the highs and lows of the past three months, I am glad to have completed another field season of our long-term study. The unexpected findings of this past summer show that our work has never been more important as we continue to monitor a rapidly changing Arctic. I look forward to 2019 and hope things improve for the Black Guillemot colony in the 45^th year of our fieldwork.

This is the last field report from Cooper Island for 2018; it is part of an ongoing series titled Arctic Change centered around George Divoky’s 44th field season studying Black Guillemots, sea ice, and climate change on a remote Arctic island off the coast of Alaska. To donate and support Divoky’s work on Cooper Island, visit the Friends of Cooper Island website.

Arctic Change, a Proteus Plumb Line Series featuring articles and field reports

George Divoky’s Planet by Darcy Frey

Global phenological insensitivity to shifting ocean temperatures among seabirds by Katherine Keogan et al

Tags Arctic, Black Guillemots, Climate Change, Climate Data, Cooper Island, Field Camp, Field Reports, Geolocators, Ocean, Science Communication, Sea ice

Arctic Change

First Fledge of 2018

Post author By Jenny Woodman
Post date August 24, 2018

A pair of Cooper Island Black Guillemots. Image Credit: George Divoky

In a breeding season and field season that has been a tough one for both the Black Guillemots on Cooper Island and the investigators studying them, today was a day of celebration as morning nest checks revealed that the oldest nestling on the island had departed for the sea during the night.

The first fledge of the year is always exciting since it is an important benchmark in our field season, which begins with recording the owners of nest sites and continues with observing the dates of egg laying and monitoring the hatching and subsequent growth of nestlings. While it is the parent birds who get all of the credit for a successful nesting season, we cannot help but feel some satisfaction having monitored daily the details of their three-month reproductive cycle. Additionally, and certainly now with the recent decline in the size of the colony, a fledged chick provides hope for the future. With sufficient luck, in three years the chick that fledged last night will return to Cooper to join the breeding population.

So we congratulate the proud parents White-Black-Gray, a bird fledged from Cooper Island in 1995 who has bred here since 2000, and Blue-Blue-Yellow, an immigrant (likely from one of the large Russian colonies) who had been breeding on the island for the past twelve years.

We are hoping that in the next few days their now independent fledgling will be joined by its sibling and a good number of the 50 birds that remain in nest sites.

This field report is part of an ongoing series titled Arctic Change centered around George Divoky’s 44th field season studying Black Guillemots, sea ice, and climate change on a remote Arctic island off the coast of Alaska. To donate and support Divoky’s work on Cooper Island, visit the Friends of Cooper Island website.

Climate Change in the Arctic by National Snow and Ice Data Center

Some Of The Oldest Ice In The Arctic Is Now Breaking Apart by Christopher Joyce

Tags Arctic, Black Guillemots, Breeding, Climate Change, Cooper Island, featured, Field Reports, NASA

Arctic Change

Uncertain Future for Nestlings

Post author By Jenny Woodman
Post date August 17, 2018

2015 chicks from nest box C-8 at 26 days. Image Credit: George Divoky

Dku-3_DUYAQHHwc — Arctic sea ice grows and shrinks during the year (seasonal cycle), reaching its annual minimum extent at the end of every summer (early-mid September). Currently, 2018’s sea ice extent is below the minimums from the 1980, 1990, and 2000 decadal averages. Image Credit: Zach Labe

Black Guillemots have their young remain in the nest for almost five weeks, being nearly adult weight and independent of the parents when fledging. Returning to the nest with a single fish in their bill is a breeding strategy found in all member of the genus Cepphus; it reflects the abundance and predictability of prey in the nearshore waters where parents forage while provisioning young.

For guillemots breeding in subarctic and temperate areas, where the nearshore provides a diverse and ample supply of forage fish, the strategy works well. In the Arctic, however, Mandt’s Black Guillemot has had to adapt to a different nearshore environment. Because of sea ice covering and scouring the nearshore much of the year, and the low productivity and biodiversity of the region’s marine waters, there is a typically a paucity of nearshore fish to feed their young.

The sea ice is central to supporting an ecosystem, with Arctic Cod being the primary forage fish, that can provide an abundant source of prey when the edge of the pack ice occupies the nearshore. Mandt’s Black Guillemot has been able to breed in the Arctic “nearshore” due to this presence of sea ice near their breeding colonies.

The strategy worked well as long the breeding colonies were adjacent to the Arctic pack ice and sea surface temperatures were low. These conditions were present for the first thirty years of the Cooper Island study and the growth and fledging rate of guillemot nestlings was high. Now, as summer sea ice retreats earlier and farther from the coast, nestlings and their parents could no longer count on having 35 days of high prey availability. This has resulted in decreased chick growth, increased mortality, and poor condition of those nestlings surviving to fledging.

C-8 26 days square — 2015 chicks from nest box C-8 at 26 days. Image Credit: George Divoky

This year, with ice visible north of the island until a few days ago, there was an abundance of Arctic Cod. A walk through the colony found many parents flying back to their nests with adult cod (some bigger than six inches). Chick weights and survival reflected this abundance with no mortality of nestlings yet being recorded this year.

However, since sea ice was blown offshore by strong south winds two days ago, most chicks have been losing weight with others having little or no growth. Based on what we have seen in past years, parent birds should soon be shifting their prey choice to the more predictable – but less preferred – sculpin. The abundance of sculpin – which are present in a range of water temperatures – and the parents’ ability to shift their foraging strategies will determine the fledging success of the nestlings this year.

One of the reasons nesting guillemots are such good monitors of prey availability in nearshore waters is the lengthy time parent birds have to provision their nestlings, as guillemot young stay in the nest for five weeks after hatching. During that time parent birds are foraging for most of each day and returning to the nest nearly once an hour with a fish.

P1010712 — Limited resources cause sibling aggression in nests. Image Credit: George Divoky

The current conditions of diminished sea ice have us approaching our daily nest checks with far more uncertainty than we did in the first decades of our study – when we expected chicks to have a steady growth rate until fledging. In the next few weeks a nest case could contain nestlings in poor condition, signs of hunger-motivated sibling aggression on the younger chick, or a number of large sculpin uneaten by the nestlings due to the size of their spiny bony head.

The one bright spot in our nest checks this year has been site E-11 where the chicks hatched from the first eggs laid this June. These nestlings are extremely healthy having been raised on adult Arctic Cod by two highly experienced parents, both over 20 years of age. The oldest nestling is just two to three days from fledging and demonstrates the benefits of parents laying eggs as soon as spring snowmelt allows.

An editor’s note on sea ice: The National Snow and Ice Data Center (NSIDC) reports that their 2018 projection for the sea ice minimum extent falls between the fourth and ninth lowest in the 40-year satellite record. You can read more of the agency’s monthly report here.

Summertime and the Sea Ice is Leaving by Jenny Woodman

Seabirds and Sea Ice by George Divoky

Work Worth Doing by George Divoky

Tags Arctic, Arctic Cod, Black Guillemots, Blob sculpin, Climate Change, Cooper Island, Field Reports, Fledgling, Geolocators, Sea ice

Arctic Change

Long-term Data Collection Serves Many

Post author By Jenny Woodman
Post date August 15, 2018

Drew Sauve (standing) and Thomas Leicester set up a noose mat near a roost site in August, the rainiest month of the field season. Image Credit: Drew Sauve

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.

Drew Sauve just finished his master’s with the Friesen Lab at Queen’s University, Canada and is starting a doctorate in September 2018 with Vicki Friesen and Anne Charmantier using the Cooper Island dataset to determine whether climate change is causing evolutionary change in chick growth. Drew is interested in evolution, ecology, genetics, and the responses of individuals and populations to environmental change.

Tags Arctic, Climate Change, Climate Data, Cooper Island, Data, Geolocators, Long-term data, Pedigree, Research, Sea ice

Arctic Change

Hatched!

Post author By Jenny Woodman
Post date August 11, 2018

A parent brings Arctic cod to their hungry chick waiting at the nest. Image Credit: George Divoky

Hatching is finally over with one very late egg hatching today after having been incubated for 34 days; 28 days is normal. The oldest nestling is 16 days old; the chick is gaining weight and doing well like all of the other 45 nestlings.

While the main pack ice is well offshore, the Marginal Ice Zone, where ice covers from 18 to 80 percent of the ocean’s surface, extends south to the entire Alaskan Beaufort Sea coast, including Cooper Island. The seascape visible from the north beach now has widely scattered floes, some with rather high vertical relief breaking the horizon, in a nearly flat calm sea. This differs greatly from what was present last year when the first week in August had no ice visible with large swells breaking on north beach. More importantly, last year at this time the sea surface temperature was well above 4 degrees Celsius while this year it is less than 2 degrees Celsius. The guillemot’s preferred prey, Arctic Cod, are typically found in waters from -2 to 4 degrees.

Labeled — A Multisensor Analyzed Sea Ice Extent (MAISE) image shows why George is seeing ice off of Cooper Island. Image Credit: National Snow and Ice Data Center (NSIDC)

The ice and water temperature conditions are ideal for the parent birds provisioning. Arctic Cod has comprised well over 90 percent of the prey being fed to chicks this year. The two oldest chicks, hatched on July 21, weighed 35 grams at hatching and now weigh 275 grams and 245 grams – the larger of the two experiencing an almost seven-fold weight increase in a 15-day period. A growth rate that rapid requires readily available prey that is both abundant and high energy, as well as two dedicated parents to return to the nest site with a fish every hour. Similar high growth rates are occurring at other nests.

This condition of the nestlings could not be more of a contrast with early August last year. Then, there was widespread mortality of younger siblings as parents could only find enough prey to maintain a single nestling. Arctic cod were absent for much of the nestling period with sculpin and juvenile sand lance comprising most of the prey. Guillemot parents turn to these alternative prey only when Arctic Cod are not available. Sculpin, with their large bony and spiny heads, are hard for nestlings to hold and swallow. They are frequently rejected with numbers building up in nest sites as the young wait for a more preferable fish.

Blob sculpin, bony fish guillemot chicks struggle to consume, lay uneaten in a nest case. Image credit: George Divoky

For the moment our daily nest weighing and measuring of guillemot nestlings has been a very positive experience. However, based on what we have seen in the last decade, we know that conditions can change rapidly in August. A strong south wind could move the ice well out of the guillemots’ foraging range or warmer waters could move eastward from the Chukchi and drive away Arctic Cod. We also know that larger and older nestlings are more able to survive changes in prey availability and that the current high growth rates will allow more individuals to survive to fledging.

This post was updated on August 11.

Alaskan Black Guillemots Fight Ice Retreat by Jonathan Amos

Energetic Value of Prey Species Utilized by Black Guillemots (Cepphus grylle) on Cooper Island, an Arctic Barrier Island by Ann Robertson et al.

Tags Arctic, Black Guillemots, Breeding, Climate Change, Cooper Island, Field Reports, Science Communication, Storytelling

Arctic Change

Soggy Fieldwork

Post author By Jenny Woodman
Post date August 2, 2018

Cooper Island chicks in 2012. Image Credit: George Divoky

2012 Chicks — Cooper Island chicks in 2012. Image Credit: George Divoky

August is the rainy month of our field season, and the first day of the month was tough for us. During our morning nest checks, it wasn’t easy to keep our hands warm in a steady soaking rain, coupled with a windchill of 27 degrees Fahrenheit.

The fingerless gloves I wear daily in the summer are a godsend for handling eggs and nestlings–wet fingerless gloves at temperatures near freezing are only slightly better than no gloves at all.

NanukCase2015 — George collecting data at nesting case in 2015; the cases were added once polar bears became regular visits on the island. Image Credit: George Divoky

The cold, wind and rain (and numb fingers) were made more bearable by the fact that our nest checks found hatching high at nests that are still being attended. All the chicks seem to be doing well in their first few days.

After hatching, guillemot nestlings are incubated by their parents for about a week. The parent’s defeathered brood patch (present in both males and female parents) warmed the egg for the last month and now provides heat to the nestlings, reducing their caloric needs.

In a breeding season where good news about the Cooper Island guillemot colony is at a premium, there are a good number of nestlings being warmed by their parents in the remaining active nests. Nearly 40 chicks are currently in the colony with a few more eggs expected to hatch soon. While overall hatching success will be low with so many nests having eggs abandoned shortly after laying, hatching success for nests that have been regularly attended will be high.

Given the high overwinter adult mortality and decrease in pairs and number of birds that did not lay or incubate eggs, this has not been a good year for the colony. But that does not mean it is a bad year for all pairs – and focusing on the success of individual nests provides a sense of optimism.

Some parents will be able to fledge one or even two chicks this year, though it will certainly not be as easy as it was for parents breeding here in the 70s and 80s when sea ice was just offshore and prey abundant. The nestlings hatching now (at 35 grams) will have to undergo a 10-fold increase in weight before flying off after five weeks of being fed by their parents. Their growth and survival will depend on the abundance and availability of fish in the adjacent Arctic Ocean.

August has always been the month when the warming Arctic has had the most effect on the productivity of the Cooper Island Black Guillemot colony. We are hoping conditions this August will allow many of the newly hatched chicks to be flying out to sea later this month – and returning in a few years to breed and maintain the colony.

Field Team Update

Drew Sauve and Thomas Leicester arrived on the island on July 22.

Drew completed a master’s at Queen’s University in Kingston Ontario this past spring analyzing heritability and plasticity in timing of egg laying in the Cooper Island Black Guillemots. He is continuing for a doctorate that expands on his master’s and includes genetic analysis of the individuals breeding on Cooper. Our daily fieldwork includes collecting feathers and other tissue for him to analyze in the lab.

Thomas is an undergraduate I met through my collaboration with Kyle Elliott of McGill University. This is Thomas’s first ornithological fieldwork and it’s been enjoyable to explain the data gathering techniques and what the data sets tell us about both the guillemots and the Arctic environment.

Having Drew and Thomas on the island has provided the personnel needed to capture more birds as they roost next to the pond in the middle of the colony. Using mats with monofilament nooses we have been able to catch and give color bands to 20 birds that fledged from Cooper Island but have yet to join the breeding population. Two of these birds were nest mates in 2015, fledging from nest I-7, which their male parent still occupies, alone because their female parent was one of the birds that died this past winter. She has not been replaced by a new recruit this year.

– George

Tags Arctic, Black Guillemots, Climate Change, Cooper Island, Field Reports, Sea ice

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This post was updated on August 11.

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Field Team Update