I was rather surprised by the offspring when I saw them for the first time. Keep in mind, I've seen the hen on some of my previous trips to Lee. The effect in the offspring is much more pronounced than in the hen. At this stage, what I think we can conclude, is that this is not a deep structural mutation, as it would be masked by grey if it was. It should also answer Willy's question about why somebody would pair a bird to a grey to get the grey phenotype. So that leaves us with a structural mutation on the cortex, or psittacin. Although we didn't do any UV tests, Lee told me about how the one chick escaped in the room. He only had the UV torch nearby and observed a yellow bird when he shined over it. That is typical fluorescence of psittacin, but more for mature birds. It isn't typical of younger birds. This observation could help solve the puzzle quicker. What is puzzling for me is that the mutation is observable in the hen (thus dominant), but seems to affect psittacin in the offspring (typically associated with recessive mutations). The green sheen over the birds is also much more uniform than for typical parblue (turquoise/indigo) fledglings and more in line with emerald. There are many questions still to answer and I'm looking forward to the next round of offspring, and to 2015 when hopefully the blue series offspring will start producing young of their own.
I'm interesting in hearing what forumites would suggest for future pairings to better understand the mutation. I have my ideas, but Lee thinks I'm too radical.
