Spot anything of note on the young bird? Aha, little spots of colour. Right. So, what do the popular Australian bird guides say about the spots. Er, nothing. Nothing? Yep, nothing. You mean one of the country's most world famed bird species shows as a juvenile a major identifier and no guide notes it?
Yep. But home and commercial breeders would know all about Gouldian Finches and their colourful light-reflecting spots. Open wide and baby birds' gaping mouths become glowing targets for food delivery. Other species may use various bright targets inside the mouth. Such knowledge will aid ID out in the field: Star Finches and Gouldians are said to look alike, apart from the spots - nodules of skin that fall off. I noticed the feature only after photographing finches in the Belgian Gardens State School's aviaries. Shows how little I know. And, too, illustrators of the Australian bird guides.
Notes: The school sells endangered species. Chicks: Wikipedia under Creative Commons