Q: I recently purchased a group of the new whiteface mutation cockatiels. I am just a beginner, and there is a lot that I have to learn. When 1 picked up the birds, I noticed that they were quite a bit smaller than what I had seen at the local shows. The breeder told me that I was used to seeing mature birds and that these would fill out in a year. Since then, I have seen some birds that are younger than the ones 1 purchased. They are quite a bit bigger than mine. What gives?

A: Whenever a new mutation surfaces, the priority is to reproduce it. In the beginning, this takes priority over all other considerations. Things such as body size and crest length take a back seat to making sure that you have enough visual specimens to ensure the mutation’s continued survival if there should be a disease outbreak.

Once there are sufficient numbers to ensure its survival, the conscientious breeder begins to concentrate on things such as size. The breeder will choose normal birds of exceptional size and will breed them to the mutations. This will produce normal appearing birds that are carrying the gene for size as well as the gene for the color mutation. Although these birds are normal in appearance and do not carry the high value of the visual mutations, they will eventually yield superior stock: birds that are visual mutations and are of outstanding size. Unfortunately, some aviculturists who invest in mutations are content to inbreed at the expense of size, color and conformation. This commonly results in the undersized birds that we often see.

It is true that your birds will fill out in about a year or two. They will appear to be bigger. This is not only due to the muscle bulk that they will put on as they mature, but to the replacement of immature feathers with mature ones. The plumage of a mature bird are longer and broader than those of an immature bird. This can be especially noticeable in cockatiels due to the lengthening of their crests as well as their tails. This maturing of both tail and crest feathers can appear to add quite a bit of length to a young cockatiel.

Since you say you are comparing your small birds to larger birds of a younger age, you probably bought undersized stock. You have two good alternatives as to what to do: The first is to breed your whitefaces to an outstanding size to improve your line. The second is to tame the birds, sell them to the pet trade, and use the money to buy good stock. If I were given these choices, I would choose the latter option.