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Ursus Maritimus


Ursus Maritimus
Photo Information
Copyright: Paul van Slooten (pvs) Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 1127 W: 254 N: 3161] (14464)
Genre: Animals
Medium: Color
Date Taken: 2008-08-27
Categories: Mammals
Camera: Sony Alfa dSLR A700, Sony 300mm F2.8 G, Digital RAW 200
Exposure: f/5.6, 1/1000 seconds
More Photo Info: [view]
Photo Version: Original Version
Theme(s): Polar Bears (Ursus maritimus) [view contributor(s)]
Date Submitted: 2008-09-28 10:17
Viewed: 4689
Favorites: 2 [view]
Points: 8
[Note Guidelines] Photographer's Note
This was one of the first polar bears we saw during our trip to svalbard,it was first walking on the shore,after a while he decided to go for a swim,while the bear was swimming away we did not follow it anymore,but I managed to get some snapshots just when he crossed our expedition vessel Professor Molchanov,picture is made hanheld from the zodiac,but as you can see no wind and waves,hope you like this one and tfw

Adaptations for an Aquatic Environment.

A. Swimming.

1. Polar bears are strong swimmers; they swim across bays or wide leads without hesitation. They can swim for several hours at a time over long distances. They've been tracked swimming continuously for 100 km (62 mi.).

2. A polar bear's front paws propel them through the water dog-paddle style. The hind feet and legs are held flat and are used as rudders.

3. A thick layer of blubber (fat), up to 11 cm (4.3 in.) thick, keeps the polar bear warm while swimming in cold water.

4. Polar bears can obtain a swimming speed of 10 kph (6.2 mph).

5. The hair of a polar bear easily shakes free of water and any ice that may form after swimming.

6. A polar bear's nostrils close when under water.

underwater swimming
A polar bear's front paws propel it through the water dog-paddle style. The hind feet and legs are held flat and are used as rudders.

B. Diving.

1. Polar bears make shallow dives when stalking prey, navigating ice floes, or searching for kelp.

2. Polar bears usually swim under water at depths of only about 3 to 4.5 m (9.8-14.8 ft.). They can remain submerged for as long as two minutes.

3. No one knows how deep a polar bear can dive. One researcher estimates that polar bears dive no deeper than 6 m (20 ft.).

C. Thermoregulation.

1. Body temperature, which is normally 37C (98.6F), is maintained through a thick layer of fur, a tough hide, and an insulating layer of blubber. This excellent insulation keeps a polar bear warm even when air temperatures drop to -37C (-34F).

2. Overheating.

a. Polar bears are so well insulated they tend to overheat.
b. Polar bears move slowly and rest often to avoid overheating.
c. Excess heat is released from the body through areas where fur is absent or blood vessels are close to the skin. These areas include the muzzle, nose, ears, footpads, inner thighs, and shoulders.
d. Polar bears will also swim to cool down on warm days or after physical activity.

Janice, PaulH, Nephrotome2, scharan1, rubic_cube has marked this note useful
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Critiques [Translate]

Paul

There is something graceful but almost happily clumsy about these bears. A stunning shot that captures a glipmse into its every day life.

Jai

  • Great 
  • Janice Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 3277 W: 148 N: 6163] (18832)
  • [2008-09-28 12:41]

Oh, how wonderful to see the polar bear there in the water. It's a view not many people would ever see. How wonderful for you this must have been Paul.
TFS
Janice

PS Interesting notes too - thanks.

  • Great 
  • PaulH Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 1137 W: 26 N: 3879] (13882)
  • [2008-09-29 4:30]

Hi Paul,
fantastic shot, that only serves to highlight the beauty and grace of the Polar Bear by including the ugliness of man in the background. Wonderful light and compositon, very well done.
Paul

Olá Paul

Uma foto genial...que belo momento você presenciou e pode registrar de uma maneira tão bonita.
Parabéns pelo trabalho!
Grande abraço,
Vera

Your shot made me smile. This polar bear didn't seem to care that you were in his world. I've also enjoyed Svalbard and its creatures. Great job!

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