Lady Gertrude's white crow was, at the time, the only known white crow in the world.
To create a sense of scale and depth when they were photographed, the castle miniatures were placed into large tanks of water to which disinfectant (Jeyes Fluid) had also been added to make it slightly cloudy. The post-production house responsible for compositing and other visual effects were in awe of the skills and ingenuity of the traditional model makers, but exasperated by the variability of the images that this "organic" method generated, making their color-correction and image matching tasks much more difficult, than with computer graphics images.
Sting owned the rights and planned to produce in the mid 1980s. He had hoped for Terry Gilliam to direct.
The white rook in this mini-series was originally intended to be digitally added in post-production. In the lead up to shooting, however, Director Andy Wilson stumbled upon an article about a child that had found and rescued a rare albino Raven. The Raven was found and given to a bird trainer who taught the animal basic responses. In order to acclimatize the bird to listening to the loud voice of Lady Groan, the trainer often played heavy metal music in the aviary.