On the slopes of the carolina appalachian mountains, ecologists have studied some closely related plethodontid salamander species for decades. many of these salamander species, when they occur in separate valleys from each other, tend to have very similar food size choices. however, when these species occur together in a mountain valley, their food choices tend to differ, with some species selecting small insects and others feeding exclusively on larger insects. this may be an example of

This is an example of 'niche differentiation'. In ecology, this is when competing species use the environment differently in a way that reduced their direct competition. In the example given above, the different species of salamander choose different sizes of prey items to avoid competition. Other strategies may be to occupy different micro-habitats within a shared larger habitat, such as in a forest, competing species may avoid competition by one occupying the forest floor whereas another may occupy the canopy layer.