This is the view to the north from the desk in my room at the bunkhouse. The houses and power lines of Kaktovik are visible, and the fog doesn’t seem that bad, especially given the blue sky. However, this is a “sucker hole” that can trick you into thinking that visibility is good, when in fact, you happen to just be in a hole of clarity in an otherwise thick fog bank.

This picture is from the same perspective, an hour later. The fog has mostly lifted – now, beyond the houses, a hangar (about ¾ of a mile away) and the northern horizon of sea ice are visible.

The reductions in flight time have given me time to catch up on coursework and get some reading and thinking done. Even when the schedule is very busy, sometimes the helicopter can be a surprisingly good place to think. The pilot is obviously busy during flight, and as passengers we are always scanning the ground for bear sign – tracks, kill sites, carcasses. However, once you get into the rhythm of scanning and tracking, your mind can return to the larger concepts of the project, turn over the data you have collected so far, or move onto other questions. I suppose it is similar to any situation where you put several people into close quarters for several hours of travel – interesting conversation can come up, or people can mostly travel along in their own minds.

We have been talking recently about how to interpret some of our data in regards to polar bear diet. We have months of analysis before we can begin drawing conclusions, but the summary of our data up until now can provide suggestions. One of the reasons the polar bear diet is interesting is that it is fairly simple in comparison to the closely-related brown bear (grizzly bear). Polar bears mainly eat seals, and this is reflected in their dentition, whereas many brown bears consume a wide variety of food items, including lots of vegetation.

The canine and incisor teeth of an adult polar bear. Polar bears have evolved larger canines because these stabbing teeth are useful in hunting, and polar bears hunt more than most brown bears. Polar bears also have reduced molars because they eat less vegetation than most brown bears, and therefore have a reduced need for grinding teeth.

One afternoon a young adult female polar bear wandered by the ship. She appeared out of the blowing snow and walked past the stern, fairly close to the ship. An hour later she reappeared and approached the ship, walking up the fantail until she was directly below the railing. Scientists and personnel from the ship were pressed at the railing above, and she just seemed to be curious, sniffing the wind and looking back at us, occasionally pawing the broken ice at the ship’s waterline.

This young adult female bear walked past the ship, eventually coming right up to the ship.

The polar bear, standing just below us at the stern of the ship.

The railing of the fantail where folks are standing is about 5 meters, 15 feet, above the ice where the bear was standing, at the aft end of the ship, the fantail. It was a wonderful chance for people to see this bear up close.

The wind finally dropped below 20 knots for a day and we flew for the bear – only to encounter heavy fog that prevented us from finding her. We located another bear that was a lower priority and we successfully captured her, yielding good data. The next day the fog dissipated and we flew for our priority bear again, but she had moved over 30 miles and we could not locate her until we received a satellite transmission at the end of the day. We remained in the area because this bear was one of the two top priority recaptures remaining, and we successfully located her twice, but both times she was traveling in large areas of broken ice which were unsafe for captures. The temperatures remained warm throughout this period, rarely dropping below 25 degrees; the water temperature remained warm as well, and sea ice simply was not forming very fast.

Poor ice near one of our priority bears.

This is a frustrating aspect of field work: success relies heavily on weather, and the bad luck of encountering stretches of poor weather can put an entire field season on hold. The only thing that can be done is planning. We planned a long field season to provide multiple opportunities to recapture each bear, and we planned on capturing secondary target bears as necessary. Thus, even though strong winds and fog really reduced our flight opportunities and poor ice reduced our capture opportunities, we had successful recaptures of target bears and we were able to process new bears as well.

The poor ice conditions we have encountered are remarkable. Air and water temperatures remained very warm throughout October, slowing the formation of new ice as winter begins. The current distribution of sea ice in the Beaufort is much more typical of late summer than early winter – we have not had to break heavy ice at all in the last 10 days. It is inaccurate to state that this warm October has been caused by climate change; climate refers to long-term patterns of average conditions, not day-to-day weather. Even in a world with an enhanced greenhouse gas effect, some autumns will be colder than normal and others will be warmer than normal. However, climate change is changing what is considered “normal.” As the earth’s climate warms, particularly in the Arctic, the type of weather we are experiencing may become common.

Graph from National Snow and Ice Data Center. Extent of sea ice over the entire Arctic is currently low compared to the 1979-2000 average, in fact, it is nearly as low as the same date in 2007, when the extent fell to a record low.

Today we disembarked from the ship, using helicopters to ferry people and luggage back into Barrow. Although the trip ended on a frustrating note, overall, it was a very exciting success. Every piece of data we gathered is unique – almost nothing is known about polar bears during this time of year, particularly bears out here on the pack ice far out at sea. I cannot wait to return to Laramie and receive data from our shore-based capture crew, which recaptured bears on the coast during the last several weeks. Before any in-depth analyses, it will be informative simply to compare data sets from the bears on ice to the bears on the coast, to see if differences are striking.