Killer Whales (Orcinus orca) evoke fearsome images in the minds of most people.  As apex predators, they have spread to most marine environments.  Further, separate killer whale populations have developed preferred local diets.  While these different populations may have some overlapping territory, they don’t mingle and they don’t inter-breed. 

Here is a brief summary of the primary killer whale populations.  They fall into three categories based on their social structure.  

      • Whales in the Resident group include males and females that tend to stay within their birth group.   They have a tight social structure.  They prefer to eat fish and squid.
      • Whales in the Transient or Bigg’s group roam along the coast.  They do not maintain a strong tie to their birth group.  They hunt marine mammals. 
      • Offshore whales are found out in deep water.  They feast on schooling fish.

Recently, studies in killer whales revealed that the females of this dominant species experience menopause.  Did you know that only humans and a few whale species go through this (difficult and uncomfortable, IMHO) phase of life?  

When menopause was discovered in the Resident group, the research team hypothesized that the social closeness of the Resident group triggered the end of reproduction in older females.  Perhaps it would not occur in the Bigg’s group.  However, despite the loose social structure, menopause happened.  So, it’s back to the drawing board.  No one knows for sure why menopause is a physical reality.  

To read more about this, check out this link:  https://onlinelibrary.wiley.com/doi/10.1002/ece3.7756

Orcas Image by djmboxsterman from Pixabay

Also reported in the news is the discovery of a new species of lizard found in central Peru.  Announced on the Pensoft blog, this is a new species of wood lizard and the male’s appearance is striking.   

Pictures can be seen here:  http://blog.pensoft.net/2021/09/01/new-beautiful-dragon-like-species-of-lizard-discovered-in-the-tropical-andes/

The researchers involved in this discovery needed to conduct their field study at night over seven years to formally describe their prized species.   That’s dedication!  Congratulations to all.

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