A pediatric nutritionist is a registered dietitian (R.D.) that has specialized in nutrition for children, so you must first become a registered dietitian. You could enroll in a bachelor's degree program accredited by the Commission on Accreditation for Dietetics Education.
Here is part 1 of Cockatiel Types and Descriptions which covers 5 types of cockatiel types including whiteface, lutino, albino, normal greys, and pied. Each ... Here is part 1 of Cockatiel Types and Descriptions which covers 5 types of cockatiel types including whiteface, lutino, albino, normal greys, and pied. Each slide gives a bried description of what each type looks like, and includes a photo. Please watch part 2 for more types. Thanks for watching. :) I own none of the photos shown in the following video.
Some cockatiels, especially some lutinos and other color mutations bred for the pet trade, tend to be rather smallboned birds. For these birds, a weight between 78 and 90 grams may be average. Cockatiel breeders that are selectively breeding their birds for showing in competition will usually have larger birds. They tend to be longer and more solid in appearance, and often weigh between 110 and 125 grams.