Biogeography of biotic interactions. Expected overlap of the geographic ranges of interacting species, considering different kinds of interactions and intensities of the interactions A competition: both competing species have a negative outcome and with high levels of competition exclude each other geographically B predation: one species has a positive outcome (blue) and the other species has a negative outcome (gray) as in the interactions predator/prey, parasite/host, herbivore/plant, Batesian mimic/model C mutualism: both interacting species have a positive outcome and (almost) complete geographic overlap is expected when the interaction is obligate D commensalism: one species has a positive outcome (blue) and the other species is neutral (gray) E higher range overlap is expected between obligate ant-following bird species and army ants than between facultative ant-following bird species and army ants.