The Knysna turaco (Tauraco corythaix), or, in South Africa

The turaco's red pigment (turacin) and green pigment (turacoverdin) both contain copper. In fact, if you stirred a glass of water with a red turaco feather, the water would turn pink! In museum species, the pigments deepen with age because the copper begins to oxidize. These birds manage to maintain their colours throughout the year.