ORCAS

      Orcas, the largest species of the ocean-going dolphin family, are aptly called "wolves of the sea" because they are apex predators in all oceans on Earth.  Adult orcas are so big that no creature preys on them.  And they hunt prey in cooperative family pods, like wolves.

     Orcas are well equipped for catching different prey species.  They are intelligent, and each group is led by an older female with experience in hunting.  They have good vision and hearing, and use echolocation to find prey.  They have several strong, pointed teeth to seize victims and tear chunks of meat off them.  They have powerful tails to be able to swim twenty to thirty-five miles per hour after prey.

     In the Southern Ocean, around the Antarctic continent, some pods specialize in snaring fish.  Other packs of orcas prey on minke whales. and a third division hunts seals.  Those different diets help reduce competition among the different pods of orcas, allowing the various pods of orcas to live together in harmony.

     Orcas that prey on Southern Ocean seals around the Antarctica Continent have a unique way of catching them.  Seals rest in the middle of floating islands of ice in the Southern Ocean, a place where orcas can not get near them.  But orcas poke their heads out of the water to look for seals on floating ice.  When a seal, or seals, is spotted, the six, or more, orcas in a family group communicate a plan with squeaks and whistles that might make a meal of those seals.  The orcas line up in the water a short distance from the seals on the ice and swim swiftly toward their intended victims.  That creates a wave that rocks the floating ice and washes the seal, or seals, off that slippery ice and into the water where the orcas try to grab the seals.  That technique may not always work the first time, but the orcas' persistence of harassing the seals time after time, tires those potential meals.  Finally, the worn out seals are washed off a chunk of ice and into the ocean where the orcas grab and ingest the tired seals no longer having the energy to escape.

     There are about 50,000 orcas on Earth, with about half of them living around Antarctica.  These dolphins prefer high latitudes and coastal habitats.  And they are the only dolphin species to breed around Antarctica.    

     Orcas are attractive.  They are streamlined for easy, swift swimming, and mostly black, with white bellies and white markings on top.  Males are twenty to twenty-six feet long and weigh about six tons.  Females are sixteen to twenty-five feet long and about four tons.  Adults of both genders have blubber three to four inches deep, which keeps them warm in ocean waters.    

     Most people will never see orcas in the flesh, but it's neat to know they exist and have interesting characteristics.  They are wolves of the sea!    

   

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