EPOW Ecology Picture of the Week -- Polar Bear Expedition, Part I

Explanation: Welcome to a special edition of EPOW, celebrating the outstanding research being done to better understand the biology and ecology of polar bears.

I was recently quite fortunate to join an expedition onto the frozen Beaufort Sea in the Arctic Ocean north of Alaska. The true experts and my main hosts -- Dr. Steven Amstrup and Kristin Simac of U.S. Geological Survey -- introduced me to polar bear research in the field, in which we were accompanied by additional researchers from University of Wyoming.

This week (and next) is a selected photo series illustrating the field work being done by these outstanding research teams.

Over the course of a week, I was able to view no less than 37 polar bears out on the sea ice -- most from a tiny fixed-wing, single-engine Cessna 185 during telemetry flights to relocate adult female polar bears that had been previously radio-collared.

We also ventured onto the sea ice in an AStar AS 350 helicopter, from which Dr. Amstrup anesthetized bears from the air with a dart shot from a rifle. We would then land on the sea ice and measure and process the bears.

Following is a photo essay of some of the field operations. Thanks to the dedicated research by these scientists, we are learning much about polar bear physiology and biology and their response to climate change and loss of Arctic ice, and thus will be far more informed for continuing the challenge of their conservation.

No bears were harmed during the research procedures; they were very well tended by these most capable researchers.

So let's begin the expedition! (As always, click on photos for larger versions.)

Searching for radio-telemetry signals. That's a Yagi antenna
protruding from the bottom of the helicopter fuselage, one antenna
on each side for directional orientation. Below are ice floes large and
small, already starting to break up in the spring -- more extensively every year.

Following the radio signals,
we spot an adult female
polar bear on the sea ice.

Sometimes all you see are the criss-crossing tracks.

This female has a COY -- a "cub of the year" (born this year).

The number on the female's back is a temporary dye marker put there the last time this bear was captured.

The following video shows Dr. Steven Amstrup
darting an adult female polar bear with an anesthetic
from a helicopter. He is leaning out the window (tethered with
a safety strap); the coiled line to his helmet is for communications
to help direct the pilot. "One Shot Steve" is a remarkable
shooter, darting each bear with a single shot.
(Video © Bruce G. Marcot)

This next video shows the darted bear starting to show
"ataxia" or difficulty in walking and standing, under the influence
of the anesthetic. We circle around in the helicopter watching carefully,
waiting for her to go down, before landing -- for her safety and ours!
Do not worry; although this looks like the bear is in distress, she is
simply beginning to fall asleep ... although this bear was doing
all she could to stay awake! (Video © Bruce G. Marcot)

Dr. Steve Amstrup ensuring the safety of the adult female -- now asleep under the anesthetic -- and of her cub.

Mom and cub doing fine. Note the radio collar.

Adult polar bears also have a bit of a yellowish tinge to their fur, although the cub's is still snow-white, aiding camouflage on the ice.

OK, I'm just posing for the photo of the year.
And ensuring that the cub will stay quiet and in place.

Taking initial measurements ... here, determining skull width, skull length, and total length.

Checking teeth for wear -- this adult looks very healthy.

Also notice the tattoo on the inner lip, put there for more permanent identification.

Taking small samples of guard hair, to be processed later in the lab for isotopes and contaminants.

Mom and cub doing well during the examinations.

We rolled the adult onto the tarp and pad to keep her comfortable.

Applying ear tags to the cub. All the bears get ear tags to further aid in identification.

The bit of skin removed for the ear tag is also bagged and labeled for later analysis back in the lab.

What is happening here?
This is a simple analysis -- the adult is fitted (non-harmfully) with small clamps to the gums and a small probe in the hind quarters ... and that unit simply measures electrical resistance (in ohms; no voltage is applied!).

Why?

Because a formula had been previously derived that tells you total body fat based on electrical resistance and body length.

Knowing body fat is very important to gauging the bears' health condition.

When we finally take off, we circle around a few times to ensure the bears are still comfortable, and that there are no other predators (male bears) lurking nearby. None was seen.

Sea ice patterns from the air. The open water is called a lead ("leed") caused by separation of ice blocks; this one seems to be refreezing. Also visible here are pressure ridges of ice caused by ice floe collisions or by refreezing of ice cracks. Tough surfaces to traverse for us, but home to the bears!

"Leave only footprints..."

(That's my camera lens cap, put there for scale.)

Next week the adventure continues...

EPOW - Ecology Picture of the Week