Introduce Middle Man

What is one has two classes where one class inherits from the other like so?

1. namespace MiddleMan.Models
   {
      public class Crow : Animal
      {
         public Crow()
         {
            bearsLiveYoung = false;
            hasLegs = true;
            canFly = true;
            lifespan = 1;
         }
         
         public int lifespan {
            get { return base.lifespan; }
            set
            {
               if (value > 0 && value < 30)
               {
                  base.lifespan = value;
               }
            }
         }
      }
   }
2. namespace MiddleMan.Models
   {
      public class Animal
      {
         public bool bearsLiveYoung { get; set; }
         public bool hasLegs { get; set; }
         public bool canFly { get; set; }
         public int lifespan { get; set; }
      }
   }

What if a third class is sandwiched between the two? What might we call this new item? A middle man?

1. namespace MiddleMan.Models
   {
      public class Crow : Bird
      {
         public Crow()
         {
            canFly = true;
            lifespan = 1;
         }
         
         public int lifespan {
            get { return base.lifespan; }
            set
            {
               if (value > 0 && value < 30)
               {
                  base.lifespan = value;
               }
            }
         }
      }
   }
2. namespace MiddleMan.Models
   {
      public class Bird : Animal
      {
         public Bird()
         {
            bearsLiveYoung = false;
            hasLegs = true;
         }
      }
   }
3. namespace MiddleMan.Models
   {
      public class Animal
      {
         public bool bearsLiveYoung { get; set; }
         public bool hasLegs { get; set; }
         public bool canFly { get; set; }
         public int lifespan { get; set; }
      }
   }

I think that is what Martin Fowler might call it. I think he might dub this sort of refactoring "Introduce Middle Man." I suppose I could be wrong.