I have no idea and I had looked for more information on this tree myself. I have one in my garden as well, I do keep my birds away from it playing safe rather than sorry, one thing I notice is that the wild birds take no interest in it apart from the odd one that lands on it and takes off quite quickly. having finches, sparrows that play often in the other trees and bushes in the garden its only my friendly Robin that will sit in it watching me hoping I can stir up a few insects for him