Category Archives: Bears

Exit, pursued by a bear

SEATTLE, WASHINGTON — For the last decade the end of my field seasons on Cooper Island could be summarized by what is considered Shakespeare’s most famous stage direction, “Exit, pursued by a bear”. It all started in 2002, when the North Slope Borough Search and Rescue helicopter had to pluck us off the island early one morning after we spent a long night taking a short-course in polar bear deterrence.  More recent retreats from the island have been less dramatic but no less emotional.  In 2008-2010 we maintained our daily measuring of guillemot nestlings while polar bears reduced their numbers nightly, breaking camp shortly after the last of the chicks was consumed. The 2011 season did not lack for bears and I am a long way from becoming blasé about their presence (or the reasons for it)  but unlike past years the recently completed field season ended on a positive note due to our deployment of bear-proof nest cases.

bear-at-nest-site

A polar bear investigates this season’s new bear-proof nest boxes.

My cabin has been protecting me since 2002 with the camp “compound” now all the more secure with the recent addition of electric fences.  This was the first year that the guillemot nestlings were similarly “bear-proofed,” as the new nest cases allowed them to survive until fledging and gave me the opportunity to monitor chick growth and prey items through early September.  The cases had the additional and unexpected benefit of preventing puffins from entering guillemot nest cavities and displacing eggs and killing chicks.  In recent years disturbance by bears and puffins resulted in the death of the majority of nestlings.

The 2011 field season also was unique due to its findings and new research initiatives.  These included:

  • An early August switch from Arctic cod to sculpin by parents provisioning their young so that some nestlings were raised almost completely on sculpin
  • The ability of the majority of parents to provide enough sculpin of suitable size that many guillemot nestlings enjoyed high growth rates and fledging weights despite the absence of Arctic cod
  • A successful trial deployment of temperature and depth loggers, attached to the bands on guillemot legs, which allow monitoring of feeding activities
  • A trial deployment of geolocators that record time of sunrise and sunset should allow us to track the post-breeding and early spring movements of black guillemots when we remove the data loggers from birds next summer.

There is much to share about each of these and I will be writing blogposts on them in the coming weeks.

While the field season and its findings were exciting and rewarding, listening to both local and national news on the radio in my cabin (and catching up on news after I returned from the field), made me aware that northern Alaska will very soon be seeing large scale oil and gas development, increasing vessel traffic and, eventually, development of a commercial fishery – in addition to the ongoing changes caused by reductions in sea ice.

The new nest cases that allow guillemot parents to raise their young to fledging and the potential for monitoring guillemot activity and movement with data loggers means that future research on Cooper Island can focus on guillemots as indicators of ecosystem health and change at a critical time for the region. Maintaining the Cooper Island study is now all the more important as the guillemots monitor a period of rapid change in the marine waters of arctic Alaska.

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Is It a Bird or a Bear?

Cooper Island, Alaska, Aug. 14, 2009 — This summer I find myself looking at images obtained over the past month on Cooper Island and thinking “what is wrong with these pictures?” But I know that the images of polar bears walking around the colony, sleeping on the beach and approaching the campsite, things I could never have imagined before 2002, are the product of habitat degradation rather than any image manipulation.

Because of the frequency and type of bear encounters in August 2008, I was looking for some way to have an alarm that would let me know a bear was approaching the cabin. This spring, when Marc Cornelissen, an Arctic researcher who has worked on Spitsbergen, a Norwegian island, offered to loan me some tripwire alarms I could use around the cabin, I eagerly accepted.

I had met Marc in April 2008 when he was mentoring a select group of European students who had been chosen to be “ambassadors” for the Ben and Jerry’s Climate Change College. Marc was touring Alaska with the students to allow them to see where climate change was most rapidly occurring. (Ben and Jerry’s funded the college in part with proceeds from the sale of a “Baked Alaska” ice cream that had the tagline “If it’s melted it’s ruined”. Unfortunately, this flavor is only available in the U.K. and Europe.) I spent a day with Marc and the students in Barrow, making a presentation to them about my findings on Cooper Island and listening to their questions and concerns about climate change in the Arctic.

Marc’s bear alarms arrived in a surprisingly small shipping container from Holland just as the field season began. The four alarms each consisted of a small plastic box, about the size of a cigarette pack, with carabiner (a clip with a spring) on two sides. One carabiner was attached to a pin inserted in the box, which triggered the alarm when pulled. When deployed, a taut string runs from the alarm’s pin to a post or other vertical structure. Increasing tension on the string pulls the pin and triggers the alarm in the box. The high pitched warbling alarm is surprisingly loud.

I set up the alarms this summer on the door and window sides of the cabin. Having tested each alarm by doing my imitation of how a bear might approach the camp, I did feel more confident when sitting in the cabin, and especially when falling asleep. Unfortunately, the tripwire lines attached to the alarms proved very attractive to the snow bunting adults and young that feed near the cabin. One of the shortcomings for birds on the island is a paucity of places to perch and it turns out that if more than two buntings sit on the string at the same time, they can pull the pin and set off the alarm. The first two times the alarms were triggered were during the day, and I emerged from the cabin with my shotgun at the ready (and adrenalin extremely high) to see a small flock of buntings flying away from the cabin — and from the high pitched alarm. It was good to know that my granola and oatmeal were safe from any seed-eating birds that might be considering a raid on the cabin. While it is true that the number of people killed by Snow Buntings in Alaska is just one less than the number killed by polar bears, to avoid such false alarms I started to deploy the alarms only as I was going to sleep.

Having the alarms was especially comforting last Friday night, since a bear had arrived on the island during a strong north wind that day. After nosing around a bit the bear had quickly gone to sleep behind a large box about quarter-mile from my cabin, so I turned in as well. At 4 a.m. Saturday morning, however, one of the alarms went off. I looked outside expecting to see the bear running from the cabin, but instead found it sniffing and licking the alarm. The bear only ran away when I shouted and made it aware that a human was in the cabin.

Later examination of nest sites and the bear’s tracks showed that it had walked through the colony turning over nests and eating guillemot chicks before approaching the cabin. The only reason I can think for the bear considering the alarm as food is that guillemot chicks do make noises when their nest sites are lifted, and the bear might have thought that the alarm was the world’s most high pitched and loudest guillemot chick.

Two nights later I had quite a different experience, which I was able to capture on the motion sensitive cameras I use for monitoring feeding activity and other nest activity. A bear that was not on the island when I went to sleep approached the cabin at 3:30 a.m. Upon triggering the alarm it turned and ran from the cabin. Here’s some primitive stills from the video — shot in infrared — of the bear-alarm encounter (the edge of my cabin can be seen along the left side).

So both times bears triggered the alarm, the alarms performed their function – which was to alert me to the fact that a bear was within 2 meters of the cabin. And now I know that when I hear an alarm I might look out to see a bear running away from the alarm – or I might see a bear trying to eat the alarm. And I suppose if I hear a high-pitched, warbling bear I will have the relationship to it that Captain Hook had to a crocodile that swallowed the clock.

The alarms were the only really positive part of the two visits by bears this past weekend. While the bears in mid July had little interest in just-hatched guillemots, chicks now apparently have enough fat and mass to be of nutritional interest to the bears. The strength of the bears, and their desire to get to the chicks,is obvious from the damage they did to nests.

Both bears had to swim through rather rough waters to reach the island, and sleep, rather than food, appeared to be their primary interest. One bear spent all day Saturday curled up in the driftwood, during a substantial rain storm. The other made a small depression behind a large box and spent all day Sunday sleeping out of the wind.

So thanks to Marc Cornelissen for allowing me to sleep a bit more soundly in the Cooper Island “Bird House” — and also thanks for his arranging to have the Ben and Jerry’s Climate Change College donate funds to partially fund this summer’s field camp. My next post will be the official “State of the Colony” address, as the first guillemot chicks are reaching the age to leave the nest.

 

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