Category Archives: Black guillemot

The Black Guillemot

The Black Guillemot has a number of life history characteristics that make it an ideal monitor of changes in the marine environment in general and the Arctic in particular. Guillemots, of which there are three species, belong to the seabird family known as auks, or alcids. The most abundant seabird family in the Northern Hemisphere, the alcid family includes murres, puffins, auklets and murrelets.

All members of the family dive to obtain prey below the sea surface typically in offshore pelagic waters some distance from land. Guillemots, however, are frequently associated with nearshore waters for most of the year, where they feed on prey both in the water column and in shallow benthic (bottom) habitats. While a number of alcid species, such as puffins and auklets, have specialized bills for obtaining a specific prey type, guillemots have a generalized bill that it uses to feed on both fish and invertebrates, although parents feed nestlings fish almost exclusively. Guillemots are also generalists in their choice of the nest sites, where they incubate eggs and raise their young. Any covered space deep enough to hide the nest contents or attending adult can allow successful breeding. Shoreline cavities are most commonly found on rocky shorelines or headlands, where guillemots are most abundant, but nesting regularly occurs in other natural cavities, such as driftwood piles and increasingly in manmade structures, such as docks and seawalls.

Guillemots are also far less colonial than most seabirds with single breeding pairs not uncommon. The ability to breed successfully as single pairs combined with their plasticity in nest-site selection allows guillemots to occupy areas and exploit nesting opportunities that highly colonial species with more restricted nest site requirements cannot. These characteristics allow it to be the most widely distributed seabird species in the Arctic Basin.

black guillemot eggsIt is what guillemots do after breeding, however, that makes them an ideal monitor of arctic marine ecosystems. While every summer the region is home to millions of seabirds, waterfowl and shorebirds, with few exceptions all undertake major migrations at the end of the breeding season and spend the next nine months in more southern latitudes. In contrast, Black Guillemots in the western Arctic undertake limited migrations, wintering no further south than the pack ice in the central Bering Sea and apparently as far north as open water is present. There are regular winter observations from Point Barrow, where cracks and open water are maintained throughout the frigid winter by the movement of ice by winds and currents, and where guillemots are apparently unfazed by the extended darkness as the sun remains below the horizon for three months. The ability of Black Guillemots to exploit arctic habitats throughout the year means that variation in their demographics, breeding biology or composition of their tissues reflects conditions in the Arctic. Those bird species that visit the region only to breed could be expected to have influences from more southern latitudes.

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Seattle science teacher returns from Cooper Island

Katie Morrison with nest box

Katie with nest box.

By Katie Morrison

Heading back to Barrow, we glide across the glassy Elson Lagoon and it is hard to imagine the wind-driven angry whitecaps that filled the lagoon just a few days before. But tonight it is calm and still and we travel with ease in our open skiff. I am glad to be wearing the precautionary orange survival suit, for though it is a lovely evening, it feels quite cold to me. It’s after ten o’clock at night, the sky is filled with shades of orange and pinks and purples, and the midnight sun seems not quite as high in the sky as it was a few weeks ago. Flocks of eider ducks race past our boat in long lines, framed by the colorful sky. As my boat pulls away from Cooper Island, I wave goodbye to George with Max and Penelope, who’ve just arrived to help finish the field season. As Cooper Island gets smaller and smaller in the distance, it is still largely present in my mind.

George banding Black Guillemots for identification

George banding Black Guillemots for identification

I’m excited to arrive in Barrow, have a hot shower, and fly home to see my friends and family and tell them my stories. But at the same time, I am already missing the peeps of the newly hatched chicks, the golden rocks on the island, the always-surprising site of the giant spool on the horizon of the West Beach, and the routines of field work.

During my stay, 133 chicks hatched in 114 nest sites. Since I have gone, 37 more chicks have hatched, bringing the current total to 170 chicks. It has been a good year so far for the Black Guillemots breeding on Cooper Island.  The retreat of sea ice has not been as extreme as in recent years and this means the guillemots’ preferred prey of Arctic Cod, which prefer cold waters, are still abundant for the growing chicks.  In past years, the early disappearance of ice resulted in a decrease in the Arctic Cod population, which led to large numbers of nestling deaths and low weights for those chicks that did fledge. This year parent birds have been bringing primarily Arctic Cod to feed their young and George, with field assistants Max and Penelope, has been busy collecting data about the prey sources. They have been deploying TDRs (temperature depth recorders) on parent birds that collect dive time data and where in the water column the birds are fishing. They are also using real-time photography and motion-sensitive time-lapse cameras to monitor and correlate the fish species being caught and brought back to the nests. Coupling the fish species identification with the TDR data, George will learn a lot about the condition of prey abundance in the Arctic Ocean around Cooper Island.

A Black Guillemot in possession of its favorite food -- Arctic Cod

A Black Guillemot in possession of its favorite food — Arctic Cod

I am anxious to hear if the Arctic Cod supply remains steady this year or if it begins to decline and the Black Guillemots are forced to switch to less nutritious prey for their young. I worry for the 170 chicks that need about a fish an hour to maintain their rapid growth rate so that they can fledge before the first snows come. In the back of my mind, I also worry about what this means for the overall conditions in the Arctic and how climate change is affecting the rest of the world.

A 2013 season Black Guillemot chick

A 2013 season Black Guillemot chick

I am back in Seattle and getting ready for the new school year, but in my mind I can still walk through the colony with George. I don’t own the story and details of each nest site (each with its own letter-number code) the uncanny way George does. But some sites still stand out in my mind:

C-13, the First Chick found in 2013! We were delighted to open the nest box and see this fluffy chick. How is that little one doing? As one of the oldest in the colony, has it fledged?

L-5, Katie’s Site. On one of my first days on the island, I discovered late-nesting birds in this nest box. Early on, the parents seemed unsure of how to take care of the nest and we would sometimes find the two parents together, flirting right outside the nest box, while eggs inside were unattended! They eventually settled down and the eggs should hatch soon. If the snows come late, there is a chance these late chicks could fledge.

O-2, the Mini-Mansion. In this site, the nest box sits at one end of a long, skinny upside down wooden floorboard, left behind by the Navy in the 1960s. The parent birds chose to nest under the floorboard and right next to (but not in) the nest box. During my stay we had three days of sustained high winds and one evening we discovered the entry sanded in and the two chicks trapped inside. We worked frantically to dig them out and were relieved to see that the chicks were fine.

I’m looking forward to George’s return to Seattle and hearing about the conclusions of the 2013 field season that I was so lucky to be a part of.

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Guillemots Go to the End of the Earth in Pursuit of Retreating Sea Ice

The annual announcement of the minimum extent of the Arctic’s summer sea ice has become one of the more important metrics by which we measure the rate of change of our warming world. This year’s minimum extent of 3.4 million square kilometers (1.32 million square miles) on September 16th broke the previous minimum set in 2007 and was half of the average minimum for 1979-2000. This 3.5 million square kilometer loss in ice extent in the last twelve years is equal to an area two times the size of the State of Alaska.

After my three months on Cooper Island each summer studying Black Guillemots and their response to the ice retreat, I am always surprised to return to find that the media is again discussing the ice loss primarily as a physical phenomenon, similar to what is being reported in the decrease of glaciers, rather than one of unprecedented biological loss and degradation of a unique marine ecosystem. The discussion of loss of tropical rainforest, another unique ecosystem undergoing major reduction, is almost always framed in an ecological context, with discussion of the effects of habitat loss on habitat and species. This contrasts with the media’s treatment of the loss of arctic sea ice where there may be token mention of some of the megafauna affected, such as walrus and polar bears, but a failure to mention that the less charismatic components of the ice-associated ecosystem, consisting of ice-algae, zooplankton, fish, seals and seabirds, now have far less habitat supporting them as they did in the last two decades of the Twentieth Century. The complete disappearance of the summer sea ice habitat in the Arctic, predicted to occur in this century, will be the largest loss of an ecosystem the planet has experienced in modern times.

The Black Guillemots breeding on Cooper Island are part of a guillemot subspecies that is one of the few seabird populations dependent on ice-associated prey throughout the year. Our forty years of observations at the Cooper Island Black Guillemot colony has shown how the rapid decrease of ice in the last decade has reduced breeding success, as parent birds provisioning young in August and September struggle to find prey in ice-free waters. In the past few months, we have found another way in which the reduction of sea ice habitat is affecting the birds. By deploying geolocators, which are attached to a bird’s tarsus and use time of sunrise and sunset to identify geographic position, on five breeding birds in 2011 we were able to track their movements from September 2011 to June 2012.

Birds
I frequently saw Black Guillemots at the ice edge in September and October during my early years in the Arctic when I was observing birds and mammals at the ice edge in the Chukchi and Beaufort seas. The unprecedented retreat of summer ice in the past decade has made me wonder where guillemots now go after breeding as the ice edge in fall is now hundreds of miles north of the Alaska coast when it used to be just offshore Figure 1 The data we retrieved from the geolocators this June shows that guillemots are still going to the edge of the sea ice in the post-breeding period, but now are having to traveling 300 to 500 miles north in search of their preferred sea ice habitat.

The extent of this post-breeding pursuit of sea ice is demonstrated in the movements of a male guillemot that has bred on Cooper Island for the past decade Figure 2. After its young had fledged on September 4, the bird flew north to the shelf break and remained there for a little over a week before starting a one-week 300 mile trip to the pack ice edge. Our discovery that post-breeding Black Guillemots now make a 600 to 1000-mile roundtrip to the fall ice edge, when in the past they encountered ice just north of the Alaskan arctic coast, has a number of implications. It demonstrates that the guillemots breeding on Cooper Island now have the increased energy demands of extensive post-breeding movements at a time when they have just completed their three-month breeding season and while they have the increased energy demands of replacing their feathers – limiting temporarily their ability to fly. The findings also suggest that guillemots will continue to move north in search of ice after breeding. As summer sea ice is predicted to decrease and eventually disappear in the Arctic over the next few decades, guillemots in northern Alaska guillemots will have increasingly long post-breeding movements that will eventually culminate in their moving north in search of ice in an Arctic Ocean that has no ice.

Our research on the movements of guillemots is continuing as we outfitted ten birds with geolocators near the end of the 2012 season. Their post-breeding movements this year will be of great interest given the record ice retreat of this past fall. Additionally, Iain Stenhouse, who supplied Friends of Cooper Island with the geolocators in 2011, and I will be working more with the 2011-2012 data logs to examine the effect of ice on movements to and from the Bering Sea wintering grounds.

–George Divoky

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