In tropical countries, field research has shown that there are large numbers of species involved in mimicry. 54 species of "Heliconius" are recognised, with over 700 named colour forms. There are four (or perhaps five) assemblages of butterflies, which include the heliconiines and their mimics. These 'mimicry rings' are called "tiger", "red", "blue" and "orange" for short. Members of each ring tend to roost together at night, fly to similar habitats and at the same time of year. Mimicry rings include both Müllerian and Batesian mimicry.