A Visit From a French Demographer

Thanks to our participation in the international Sentinels of Sea Ice (SENSEI) project, this summer the Cooper Island field camp was visited by Pierre-Loup Jan, the post-doc analyzing the Cooper Island demographic data set. After 44 years of sharing the island with a seabird with a French name (“guillemot” is the diminutive of Guillaume – the French version of “William) it was fitting to have a French researcher on the island with me.

We are very fortunate to have Pierre-Loup and his colleagues in France collaborating with us. He was a welcome addition to the 2019 field camp as he provided assistance, insights and humor during a summer when all were needed. His musings about his time on the island are below.

My impressions and observations of Cooper Island

I remember that the first day I met George, I was immediately impressed by his massive, long-term data. It was in the French countryside, in a wildlife biology lab in the center of France with so few towns around that you could consider it as remote as Cooper Island, only with a bathroom. This place was about to become my home but I was still exploring it at that time, freshly hired as a modeler to investigate the population dynamic of black guillemots. To be fair, the data by itself was not as impressive as the story behind it, and I was really excited to meet someone like George, who spent three months a year, for the past 45 years, in an island of the Arctic Ocean. I was even more excited when the same man invited me to come with him the next field season, which is the kind of opportunity you don’t have every day when you are a modeler (which means I spend most of my time processing tables of data to obtain neat plots and curves on a computer).

Pierre-Loup Jan on Cooper Island

Long story short, 9 months, two trains, three planes, and one boat later, I set my foot on Cooper Island, ecstatic to see with my own eyes the colony but also anxious about its health: sea ice retreat had reached a level never seen before two years, and I wasn’t sure how the birds would handle this summer.
Saying that the Cooper Island colony is one of the most beautiful guillemot colonies would be an obvious lie: it’s totally flat, for some reason some guy left black and grey suitcases everywhere, and it seems that previous buildings were just blown up by the navy before they left. However, Cooper Island is undoubtedly one of the best colonies to observe and understand the lifestyle of marine birds. I had read about the birds and, of course, discussed a lot about them with George before coming to the island. But nothing can beat the fact of seeing them and, instead of being lost in a complex and messy aggregate of rocks and cavities, even someone as unfamiliar to fieldwork as me could easily distinguish each nest, which were like many little houses with parents coming back after fishing. And with that, everything I was told about their behavior and all of the data I had been seeing on my computer screen made much more sense to me. I could directly observe with my own eyes the nest fidelity of the couple, the queuing birds waiting for an opportunity, the feeding of chicks and the way their weights change while growing.

Two of the three thousand birds in the data set that Pierre-Loup is analyzing

I hope that, at this point of the story, you don’t perceive me to be a geeky scientist spending his days looking at bird data on a computer. Nothing could be more wrong, because I also look at climate data. Particularly sea ice cover, giving the utmost importance of this area for the feeding of black guillemot. Unfortunately, I couldn’t observe it with my own eyes: the ocean around the island was completely ice free. Liquid water all around the island, as far as the eye can see, very different to some of the early pictures George took from the island. But data doesn’t lie, and the current sea ice cover dynamic made me expect this, the same way I expected what would happen during the period of chick feeding: breeders were not able to feed their chicks appropriately, and 75% of them died of starvation while I was monitoring them with George. It was truly heartbreaking to open a nest box just to find the bodies of chicks that could not be fed in time. Living this experience definitely strengthened my resolve to show how climate change affects wildlife. The long-term existence of this colony seems more and more uncertain every year, but at least studying them gives us the best opportunity to understand, warn, educate, and hopefully prevent what is planned to be the most massive lost in biodiversity since humans first wandered the earth.

Coming to Cooper Island was not just beneficial for my work: it was also an astounding experience. The island was way bigger than what I thought: I guess it is always complicated to appreciate distance and area when looking at maps and pictures. I kind of expected it to be limited to the guillemot colony, but this gravel bar in the middle of the arctic ocean has so much more to give! I was amazed by the diversity of birds I was able to see there, and took as many pictures as I could to be sure to make my ornithologist colleagues jealous (before asking them the names of the bird species). Of course, birds are not my #1 bragging material: I was welcomed by the sight of polar bears on the first morning, and had the pleasure to see three more of these animals during my stay. The size of those majestic beasts was breathtaking and, unlike my companions on the island, I couldn’t wait to see the next one. One could say that looking at them walking along the beach at a safe distance behind an electrical fence is not really bragging material, but It all depends on how you tell the story.

A polar bear resting near two nest cases protecting Black Guillemot nestlings.

The island being bigger also means that It was not all sands and rock, and I was surprised to find a wide area of tundra on it. I really enjoyed walking in this peaceful green place which made me think how the very first terrestrial landscape probably looked. I spent several hours on the tundra patch, looking at mosses and grasses that grew under the arctic climatic condition, surviving on the few nutrients they could get on this isolated island. As the famous Dr. Ian Malcolm would say: “Life finds a way”.

Aerial view of Cooper Island. Photo by Gary Braasch

Living on the island comes with its challenges of course, and the wind and rain doesn’t make it any easier. Fortunately, George’s hospitality and companionship make up for it, and the hot drinks and warm meals that waited for us in the cabin made the fieldwork bearable under any weather. Meals and cocoa breaks (I don’t drink coffee) were also great opportunities to share stories with people on the island, and gave me the chance to spend time with truly inspiring people, not only George but also Catherine Smith and Katie Morrison, who are doing an amazing work with the Friends of Cooper Island nonprofit, and Maria Coryell-Martin, an expeditionary artist that produced exceptional drawings of the island wildlife and landscape. The downside of those times were the occasional harassment by George, who liked particularly to make jokes about me being a youngster and a Frenchman. Of course, I had the courtesy to let it slide without responding: He is cranky, like most old people, and at times can lack tact, as many Americans do. Joking aside, interacting with these people added a human dimension to my travel experience, and I headed back to France with great memories in my head and new contacts on my phone. I will now do my best to make the most of it for what comes next. As they say in France :

“George ne parle pas le français et va certainement croire que je dis du mal de lui vu que son nom est au début de la phrase. C’était vraiment une superbe expérience.”

Pierre-Loup JAN

The Darkness of August

by George Divoky

Image Credit: Mike Morrison

While much has changed over the course of the 45 summers I have spent on Cooper Island, as warming from anthropogenic carbon emissions has modified the Arctic’s snow and ice habitats, one thing has remained constant. The sun is always above the horizon for 24 hours when I arrive in early June and it does not set until precisely August 2.

The importance and impact of that constant daylight is hard to overstate. When I arrive on the island I am not constrained by the day-night/light-dark cycle that I just left in Seattle, and I can work on whatever schedule I like while setting up camp and conducting initial colony censuses. Equally important is the high serotonin level associated with the constant daylight, which increases the optimism one typically has when starting a field season at any latitude. That optimism is also amplified by seeing the guillemots, some of whom I have known for over two decades, initiate breeding.

After the sun sets in early August, “nighttime” for the following two weeks consists of an increasing twilight period until the third week of the month, when the sky becomes dark for the first time since before my arrival. The loss of daylight is the first clear signal that the summer is ending. Despite the major impact on fieldwork and my psychological state, I used to welcome the arrival of August darkness as it allowed the guillemots to complete their breeding season. Black Guillemot young fledge under the cover of darkness. After 35 days in a nest cavity, the chicks depart the colony independent of their parents. They fly off at the darkest time of night and quickly move offshore to reduce the risk of predation by diurnal shoreline predators like gulls, jaegers or falcons.

A fully grown chick outside its nest case waiting for darkness to fledge

In recent years, however, the darkness of August has been a different experience for both the colony and for me. In the first two decades of the study, when the colony was almost three times its current size and breeding success was high, large numbers of nestlings would fledge every night. My dawn nest checks during those years found many just-vacated nesting cavities which provided daily evidence of that year’s breeding success and the promise that future breeding seasons would see large numbers of birds returning to their natal colony on Cooper Island.

However, the period of August darkness became quite different as the Arctic warmed. Starting in 2002, when annual summer sea ice melt notably increased, we began to see polar bears on Cooper Island. Polar bears on land are active during the nighttime hours and it was not uncommon to wake up in late August to find that bears had flipped over the wooden nest boxes and consumed guillemot chicks, sometimes wiping out half of the colony in one night. We addressed bear predation by replacing the wooden nest boxes with bear-proof plastic cases in 2012, but the continuing loss of ice that drives the bears to land each summer is also making the guillemots’ preferred ice-associated prey, Arctic cod, unavailable to parents for feeding their young.

In the 2019 breeding season that is just ending, decreased prey availability due to both a lack of sea ice and high sea water temperature underlie the death of 75 percent of the nestlings. While hatching success was good, only 25 percent of the 130 nestlings survived until late August. In past years when sea ice was just offshore and Arctic cod were abundant, over 75 percent of the nestlings would be expected to fledge. This year’s nestling mortality occurred mainly in late July and early August, when nearby ocean waters were so warm (up to 9 C or 48 F) that even the less preferred alternative prey, sculpin, were scarce. Guillemots typically have two-chick broods with the younger chick being fed less during periods of low prey abundance. This year none of the younger siblings survived past early August, the first year without bear predation that no pair was able to fledge two chicks.

The small number of surviving nestlings are now fledging. Having monitored them since they were eggs, including weighing them daily during the five-week nestling period, I have come to know them as individuals and am pleased when I open a nest case to find the surviving chick had left the previous night. But I am also aware that the extremely low breeding success this year, coupled with similar low success in the past two years, will cause the number of breeding pairs in the colony to continue to decline. Although the few chicks that have fledged in recent years can be expected to return to Cooper Island in two to three years, if they survive the ongoing loss of ice in their winter habitat in the Bering Sea, realistically the Cooper Island colony of Black Guillemots can never be expected to regain its past numbers nor its past success.

In earlier years both the bright start of a field season, as birds laid their eggs, and the darkness of late summer, when chicks would fly off into the night, could raise one’s spirits. This year, the darkness of August has been a period of melancholy and uncertainty of how long the colony might persist.

Loss of Sea Ice Takes Its Toll on Seabirds

By George Divoky

Pierre-Loup Jan, Katie Morrison, George Divoky, and Maria Coryell-Martin monitoring changes to the colony in August 2019 on Cooper Island.

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 author notes 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.” They go on to quote me describing the high rate of chick mortality from the loss of sea ice, which limits guillemots’ access to their preferred prey, Arctic cod.

Read the full post at Proteus.

Friends of Cooper Island