James Gibson’s theory of affordances suggests that what animals perceive in their environment is not so much the properties of individual objects but rather the possibilities for action they enable. There’s a sense here that what things are and what things mean show up for the animal at the same time. On Gibson’s view, an ecological niche is thus best understood as a set of affordances made available by an animal’s capacities. For example, a niche may afford climbing, sheltering, swimming, running, standing, eating, and so on.
Gibson notes that there’s a tight link between animal and niche, where the abilities of the animal and the properties of the niche mutually act to constrain the set of available affordances. In the case of humans, Gibson observes, the situation is a bit different in that we actively engage in the planned construction of our own affordance landscapes. (Had Gibson been alive today he no doubt would have paid greater attention to the niche-constructing actions of all organisms.) We can see a gymnasium as affording fitness, a town square as affording meeting, a library as affording reading, for example.