Polar bear #19 - July 13

The National Geographic Explorer is not an ice breaker, it is an ice pusher. Icebreakers are large heavy, powerful ships with hulls that are designed to ride up on the ice & then break it by the ship's weight. The hull shape then pushes the broken ice below the icepack so that a clear path is created. The nuclear-powered Russian ship that goes to the North Pole can make it's way through ice that is up to 5 meters thick.
The Explorer has a "v" shaped hull and a bulbous nose that projects just below the water line. It is designed to go through broken pack ice by pushing the pieces out of the way. The process is a bit noisy & progress is slow but eventually it makes headway.
There were many seals on the pack ice around the ship including ringed seals, bearded seals & hooded seals - all favorite polar bear snacks. When the call "Polar bear on the ice" went out over the intercom, 4 bears had been sighted including a mother with 2 cubs. This time we couldn't get very close without disturbing Mom while she was grocery shopping but we were able to watch. While the cubs rolled and romped a little way off, mom crouched next to a seal breathing hole like a giant cat. She remained motionless for 15 minutes waiting for the seal to reappear. This is called "still hunting" and works only if the bear chooses the right hole for each seal will typically use 10 to 12 such holes varying it's use pattern randomly. An experienced bear can smell which holes were used recently & guesses where the seal will appear next. Seals can stay underwater for half an hour & are very sensitive to vibrations thru the ice so the bear must be very patient.

After 20 minutes, the cubs got restless & mom felt they were too close so she abandoned the hole & walked downwind from a seal that was resting on the ice. When she came to some open water that was separated from the seal by a large patch of floating ice, she quietly slipped into the water while the cubs waited on the ice. It appeared that she was preparing for a maneuver called "aquatic stalking" where the bear swims under the ice & then pops up out of the water right in front of the seal. We observed for quite a while but did not see the conclusion of the hunt. To provide for herself & the cubs, mama bear has to capture a reasonably-sized seal about once a week while at the same time training her young to hunt on their own. We surmised that we could have witnessed a training exercise. All-in-all, pretty fascinating.