Well, it has a blue eye ring so it's either a Fitzroy, an Eleanora or a Lesser Sulfur but I doubt it's a Fitzroy because they are very rare - and the only real noticeable difference between the Eleanora and the Lesser is size and that cannot be judged from a picture. There is also the bald patch behind the crest as well as the body yellow suffusion that Eleanoras have and not Lessers but, to tell you the truth is almost impossible to say with any certainty whether a sulfur crested too is one species or another because there has been A LOT of interbreeding and almost all of them are now mixes. Tritons also have the blue eye ring but their crest is wider than what this bird has.
Now, diet has a lot to do with their plumage coloring. I took in a 17 year old Lesser Sulfur but after a year of a fresh food diet and after a normal molt (he came to me in August and as he had been kept to a human light schedule, he never had a full molt the first year), I realized he was not a Lesser after all (he developed a lovely, lovely yellow suffusion all over his body, dark yellow ear patches -he had none before, and his crest is now almost orange!)




