You got it! I agree, the riddle was quite unorthodox. I went for a riddle that tied the "Chester Zoo" aspect of the game into things a bit better, since without knowing they keep those 5 species one wouldn't be able to solve it.
For others: "red" referred to red-crested turaco, "white" referred to white-crested turaco, "banker" referred to Schalow's turaco, named after Hermann Schalow, a German banker, and "explorer" referred to Fischer's turaco, named after Gustav Fischer, a German explorer.
Additionally, the "green with envy" line stated that those 4 species (all of one genus, "Tauraco") were green whereas the other wasn't, and was therefor 'special' in a sense.
I'm very pleased by the answers I got! A lot of things that unintentionally fit really well.