My male cockatiel is such an active boy. He is 8 years old and just became a papa. But one day, he flew on my shoulder and pooped. Yeah, I'm used to that, but what im not used to is seeing yellow and foul smell poop. I have been feeding the female soft foods (apart from their normal diet) for the babies. Hard boiled egg yolk is part of the soft foods. The male cockatiel just begun to try the egg. He wasn't as interested in the egg yolk as the female was in the beginning. But I'm worried that he might be getting sick. Could he have some disease? Or is it the egg that's making his poop yellowish/white and really sour smelling?