EPOW - Ecology Picture of the Week

Parrot Mutation

Australian King Parrot (Alisterus scapularis), Family Psittaculidae
Wye River, Victoria, Australia

Explanation:  This Australian King Parrot is sporting a brightly visible sign of a genetic mutation.  

The pair of photos above are both of adult females.  The one on the left is the normal plumage coloration, but suddenly the bird on the right showed up with a very unexpected yellow coverage.

We are in the coastal town of Wye River along the Tasman Sea in southern Victoria, Australia, in a native Eucalyptus forest overlooking the ocean.  Here, king parrots, along with other local birds, have become acclimated to tourists likely feeding them from their home decks, as these birds and others showed up quite interested in our outdoor morning breakfast.  

  
Genetic mutations are the stuff of evolution.  Whether a mutation has adaptive advantage or not will determine if it will spread throughout the population and become the new normal.  

So what possible advantage, or disadvantage, might this yellow female have?

One possible advantage is to appear to be more fit than other females, and thus be selected for mating more frequently than the more drab-appearing green females.  However, the yellow bird I observed was solitary, without a mate. 

But a possible disadvantage is that the yellow stands out more than the green, putting the bird at greater jeopardy of predation by raptors and other predators, in which case her genes will fail to be passed on.   

Plumage mutations in king parrots and of other Australian parrots are not unheard of, with at least one known to be fully yellow (see this page, scroll half way down).  Mutations also are of interest to birders.  
  

 
left:  Normal plumage, female Australian King Parrot.
right:  Abnormal mutated plumage, female Australian King Parrot.

  
Yellow king parrots have been reported but apparently mostly or only in the males.  This female variant maybe something new.  

By the way, males of this species appear quite different than the females -- a case of sexual dimorphism -- and have an all-red head, chest, and belly.  
  

  
Information:
     Ahyong, J.  1981.  Some Australia parrot mutations.  AFA Watchbird, Journal of the American Federation of Aviculture 8(1):39.

Acknowledgments:
     My deep gratitude to Dr. Trent Penman and to Sandra Penman for hosting me in Victoria, including this wonderful visit to Wye River where we enjoyed friendships with these parrots, with nocturnal koalas, and with each other.