Lately scientists have observed the migration of polar bears in the northwestern Canada, Beaufort Sea and Chukchi Sea of Alaska. They conclude that polar bears rely on sea ice so much so that they cannot live without the it. They will move with the ice. However the bear’s movement is not so random as scientists previously thought nor do they passively follow the ice movements. Perhaps it’s time to discuss how do polar bears migrate in the tundra. You’d like these interesting polar bear migration facts.
Do Polar Bears Migrate? – Polar Bear Migration Routes
- Depends on the region polar bears move in a linear fashion and their movement is far greater than many other terrestrial predators. Polar bears’ close association with the sea ice suggests that the bear has varied productivity patterns and it mainly depends on the habitat characteristics.
- Biologists calculated the annual distance covered by a polar bear in a straight line and estimated at 6,200 kilometers but averaging 3,415 kilometers. Polar bears typically move at a speed of 4 km/h which they are able to sustain for longer periods.
- They are thought to cover as much as 50 km/h in a single day. Polar bears walk 50 kilometers without resting.
- The activity areas of female polar bears are recorded at 149,000 square kilometers. The largest area is estimated at 597,000 km2 whereas the smallest is about 13,000 km2.
- In the Beaufort Sea polar bears relatively travel more probably due to the dynamic behavior of the sea ice. The average activity area is estimated at 244,463 km2. They will cover 5542 km of mean distance each year.
- When the ice moves at 15.5 kilometers per day the bear moves at 14.1 kilometers each day. A polar bear always moves against the ice probably due to the fact that it provides grip over the ice.
Polar Bear Movement in the Canadian Arctic Archipelago
- In the Canadian Arctic Archipelago the ice movement is greatest and so as the polar bear’s. In the Davis Strait and Baffin Bay ice bears travel great distances. The unpredictable behavior of the sea ice in Chukchi Sea, Beaufort Sea, and Baffin Bay makes the polar bear movement predictable. The greater is the volatility of sea ice the greater is the movement of the polar bear.
- The largest monthly activity in the Beaufort Sea is likely to be observed in June and July as well as in November and December. Polar bear travels the most during these periods. From May to August polar bears largely move towards north whereas in October their direction is towards south. (See in detail: How Do Polar Bears Move?)
- Polar bear movements decrease in October because the ice begins to freeze in the southern Beaufort Sea. October is probably the first month when the shallow waters will cover with thin ice sheet.
- Unlike in Beaufort Sea the greatest movement of polar bears inhabiting Viscount Melville Sound is in May to July. They will further increase their movements in January.
- The summer movements are also high; the reason behind that is the quick retreating of sea ice.
Read More: Do Polar Bears Hibernate?
Polar Bear Migration Map
Polar Bear Movement in the Viscount Melville Sound
- In the southern and northern Beaufort Sea the peak movements occur in November and December. Polar bear movements become lowest in May.
- During winter in Viscount Melville Sound polar bears do not appear to move much. This is because of the occurrence of thick ice sheet. However ringed seals are present in fewer numbers in Viscount Melville Sound as compared to those in Alaska or West Greenland.
- In the Viscount Melville Sound ringed seals live in tidal cracks and pressure ridges and they find it difficult to come to the surface for breathing because the water is covered with multilayered ice sheet. On the contrary the ice in the southern Beaufort Sea seems to be volatile allowing seals to breathe with ease.
- As it turns out polar bears in the Beaufort Sea spend much of their time foraging for seals whereas those living in the Viscount Melville Sound are known to rest and conserve energy.
- Nonetheless, polar bears inhabiting the Viscount Melville Sound have one advantage over the Beaufort Sea bears that is, the predictable behavior of sea ice in the Viscount Melville Sound.
- The ice in the Viscount Melville Sound doesn’t appear to move much which means that bears can predict the precise areas for hunting seals in early winter. Same is not the case with bears living in the Beaufort Sea because they cannot identify the hunting areas due to changing character of the sea ice.
- The constant change in the ice of Beaufort Sea and Baffin Bay requires polar bears to be more creative. Polar bears must learn to devise new foraging strategies each passing month or even day.