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.

About twelve hours after receiving the phone call, I had dropped all other plans and I was on a plane to Alaska. Within several days we mobilized two helicopters and pilots up to the coast, rounded up all the necessary gear, and performed the capture near Kaktovik. After examining the bear closely, fortunately, she was not in ill health and she was not experiencing any complications from previous sampling. Although it is difficult to know, it seems she simply had a tough spring, perhaps due to poor hunting success or other factors.

I did not return to Laramie until the following Monday, after missing the first week of classes on campus. I was very happy that the safety of Kaktovik residents and of the bear had not been jeopardized, but it was certainly a reminder of the important complexities involved with studying polar bears on the north slope.

Today, as I write this, I have about two hours to finish packing before departing for Barrow, Alaska. My advisor Dr. Hank Harlow and I will arrive in Barrow tomorrow night at about 7:15 pm, where it will be around 25 to 30 degrees (Fahrenheit) and hopefully with a little snow on the ground. My co-advisor, Dr. Merav Ben-David, will arrive the following morning, and eventually a total of about 20 personnel will show up. The group includes our collaborators from USGS and USFWS, a photographer, a film crew, a high school teacher, and several other Arctic-based research groups. The other projects are varied, focusing on primary production in sea water, algal growth on the underside of sea ice, and sea birds and mammals. All 20 personnel will be ferried onto the USCG icebreaker Polar Sea via helicopter, hopefully on Saturday. Once onboard, we will cruise towards the edge of the sea ice, about 400 miles north of Barrow.

Every year, the sea ice reaches it minimum extent around mid-September, and this year’s minimum appears to have occurred on September 12th. The National Snow and Ice Data Center has posted a map and description here; from this point on, the ice will be expanding as temperatures drop below freezing across the Arctic. Thus, as we cruise north, the ice will be slowly expanding south towards us.

The website Cryosphere Today has a color-coded map depicting current sea ice conditions, shown below. Remarkably, the three smallest minimum extents during the era of satellite measurements – beginning 1979 – are 2009, 2008, and 2007. In other words, the Arctic has had less ice in the last three summers than in any other summer since 1979.

Arctic sea ice conditions as of September 22, 2009.

I am very excited about working from the icebreaker. It is an incredibly rare opportunity to not only get a sense of the far northern sea ice environment, but also to collect valuable data from a important species that is so strongly associated with it.

The United States Geological Survey (USGS) has been capturing polar bears in late winter in northern Alaska for decades, and their research provides much of the current science regarding polar bears. The USGS crew that performs captures often stages out of different towns in the Arctic, including Kaktovik, to access different regions.

The city of Kaktovik, Alaska, from the air. The airstrip is in the foreground. There are no roads to Kaktovik – you must fly in, travel by ocean, or make a long journey by land through the Arctic Wildlife Refuge.

On Friday, a USGS scientist picked me up at the airstrip when I landed in Kaktovik. We returned to the bunkhouse where the crew was staying and I jumped in to help to prepare platters of cheese and sausage, a pot of chili, and lots of coffee. We brought the food down to the community center and participated in a community meeting. A scientist from USGS and me had the opportunity to meet residents and discuss research activities based in their town, activities which involve an animal many folks there know intimately – the polar bear.

The USGS crew had already been capturing polar bears for several weeks. The next morning the temperature was -20 degrees (Fahrenheit) with light wind, and I went out with them. We had 4 people – a pilot and 3 researchers – in the helicopter. We departed Kaktovik and flew north over the ocean. We saw a lot of tracks but no polar bears until the afternoon. The USGS scientist used a dart gun to inject the polar bear with a drug that immobilizes the animal and puts them under anesthesia. Once the animal was down, we landed, unloaded our gear, and gathered samples from the bear – we weighed it, measured its length, girth, and skull size, and took samples such as fur and blood for later analyses.

One of the polar bears that we captured for sampling on Saturday, on sea ice several dozen miles north of Kaktovik. This is an adult male bear which weighed about 750 lbs.

A front paw of the same adult male. The size of polar bears always amazes me. This bear had paws that were as wide as my hand is long, and it was not even a large male. The largest males can weigh over 1500 lbs, twice as much as this bear. Their claws are shorter and much sharper than a brown bear (also called grizzly bear) – polar bear claws are better for walking on slippery ice and grabbing seals. The long claws of a grizzly are better for different tasks, such as digging up roots for eating.