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.
The Black Guillemots on Cooper Island continued to show
signs of a turnaround from the poor breeding season of 2018 as egg laying and
incubations has occurred in over 75 nests this year, compared to only 25 last
year. The breeding population saw the
recruitment of 20 birds that had fledged from the island in past years but had
yet to breed. This is important since it
shows that even with the decreased reproductive success and poor ice conditions
of recent years, some birds are surviving to breeding age (typically 3-years of
age) and returning to their natal colony, Cooper Island. A major surprise was the return of a bird
that fledged from the colony in 2012 and had not been seen since.
Unlike last year when daily nest checks found recently laid
eggs being abandoned by parents, this year has found all eggs being regularly
incubated. Incubation is the least
energetically demanding stage of breeding as the parent birds, which both
incubate, take shifts of approximately 12 hours each day, having the remainder
of the day to forage for fish. Last
year’s large-scale desertion of nests with eggs indicated birds were either
starting incubation in poor condition or encountering low availability of prey
during incubation. Discovering the
potential reasons for the differences between the last two years will have to
wait until the fall when I have internet access to environmental data.
While our daily nest checks have provided hope for high hatching success this year, other observations while we walk around the colony are causes for concern. Most noticeable is the almost complete lack of guillemots sitting outside near nest sites or at the edge of the pond in the center of the colony, where guillemots have typically roosted when not incubating eggs or feeding young. The daily period of colony attendance, approximately midnight to noon, used to have birds throughout the colony, while this year we see only the occasional lone bird or nonbreeding pair. There is little visual evidence that the island supports a colony of over 150 birds. Additionally, in early July we experienced a rapid disappearance of sea ice with the island being nearly surrounded by ice to no ice in sight in 2-3 days. Both of these factors suggest that, despite the positive indicators seen in breeding effort and nest attendance, there are reasons to be concerned about the upcoming period of nestling growth and survival.
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.
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.
Photo by Joe McNally
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.
Joe and George in the cabin on Cooper Island. Photo: Joe McNally
