Answer: I have not been able to uncover a documented case of an animal being poisoned from eating a bird killed from eating nandina berries.
However, Bob Sargent, Program Manager of the Nongame unit of Georgia’s Nongame Wildlife Conservation Section has advised me that he talked to a veterinarian familiar with nandina poisoning cases. This researcher indicated that secondary poisoning is theoretically possible, especially if an animal consumes a bird that has just died (e.g. its carcass is still warm) or, if the dead bird’s crop is packed with nandina berries and the scavenger eats the crop. The reason for this is that the cyanide rapidly dissipates when it is consumed.
The veterinarian went on to say that, if a cedar waxwing eats just a few nandina berries along with other fruits and berries, it will probably survive the experience.