A mutation in general is a change in the genetic makeup. This can refer to any change (difference) whether it be a change to the color, shape, physical characteristics, or even something internal. Of course in bird mutations we generally refer to color and or other physical characteristics that can be seen. Such as the feathers on the feet of a silkie chicken or if we all of a sudden had a red or purple cockatiel, imagine that! Or the already in existence crested parakeet.

A mutation in cockatiels (birds in general) is a change in what is considered to be normal for what we have already established the cockatiel to be. Which means it can be a change in color or physical appearance of any kind. Some may even call a new mutation a freak which actually it is at first, but once established, and it is proven that more of the same type of change can be produced in generations from the original it becomes a mutation and most often becomes highly prized and very sought after.

There have been mutations in the past that were lost, because for one reason or another they were not developed. Often there is disbelief in the fact said mutation could be developed. I myself once saw a cockatiel years ago that had longer feathers coming straight out from the cheek patches on each side it was a female lutino, that was perfectly normal in every way except for the cheek patches. The owner would not sell the bird and was convinced without trying that it could not be developed. It was just a novelty to him, which indeed it was that. I felt bad because I knew it could have been so much more, I often think of that bird.

In the middle 80's the pearly pied was very sought after, but due to lack of knowledge on breeding genetics, a lot of people trying to reproduce it were very frustrated with there results and often gave up. They were often breeding a pearly pied hen to a gray bird and getting all gray birds. What they failed to realize was that the offspring although looking just gray did carry the very genes that they were trying so desperately to produce. So they would sell these split birds thinking there original pair would surely produce what they sought the next time, which of course didn't happen. It would have actually happened with the second generation males being split to both pearl and pied when breed to pied hens would have produce pearly pied daughters and pied males split to pearl. I will not go further on this because this is just a small look for you to see how some mutations really take time to be developed. Thus you can see the reason why many give up and potential new mutations are so often lost.

You can have more than one mutation on a single bird, even multiple.