These are the only mates for life I could find so far. Monogamy is rarer than I thought.
  
    - Castor - Beavers 
 
    - Anas platyrhynchos - Mallards  
 
    - Corvus corax - Ravens  
 
    - Hylobates lar - Gibbons   
 
    - Cygnus buccinator - Swans  
 
    - Psittaciformes - Parrots (with the exception of the Kea and the Kakapo) 
 
    - Aptenodytes forsteri - Emperor Penguins 
 
    - Ceratiidae - Deep sea Anglerfish take monogamy to an extreme 
 
    - Canis lupis - Wolves (for the most part) 
 
    - Peromyscus californicus - California Mouse 
 
    - Microtus ochrogaster - Prairie Voles   
 
    - Columbidae - Pigeons 
 
  
            jun 30 2010 ∞
 jan 27 2011 +