I'm baby-sitting my girlfriend's cockatiels and am curious about one of the cockatiel's looks. The gray, 3 year old, female?, is larger than most other 'tiels, fairly quiet (I'm NOT complaining), refuses to grow that cockatiel "top knot" (how come?), and her face feathers (around her beak) seem ... puffier? ... too. My girlfriend seemed to think that it was something the bird would "grow out of" ... but after 3 years. Hmmm. Seriously, is it something in Pretty Bird's diet? A nervous condition? Or just genes?
Most likely the puffy feathers on her face are from molting. If after three years the tiel hasn't grown a full appearing crest, it will probably not and that is hereditary.