Otters in Snow Forever Stamps, 2021 Booklet – Winter Cards and Letters

Male sea otters are larger than females and weigh between 49 and 99 pounds.  Females typically weigh 30 to 70 pounds.  Sea otters are unlike other marine mammals in that they don’t have blubber (fat) to keep them warm.  Instead, they depend on their thick, waterproof fur to do the job.  Because of this, sea otters spend much of their time fluffing and grooming their fur to ensure its oils are evenly distributed.  They also do this to keep an adequate amount of air trapped in their fur, which helps keep out water and aids in buoyancy.  Sea otter fur includes up to one million strands of hair per square inch, making it the densest of any animal.