Data from: Spatial discounting of food and social rewards in guppies (Poecilia reticulata).

In temporal discounting, animals trade off the time to obtain a reward
against the quality of a reward, choosing between a smaller reward
available sooner versus a larger reward available later. Similar
discounting can apply over space, when animals choose between smaller and
closer versus larger and more distant rewards. Most studies of temporal
and spatial discounting in nonhuman animals use food as the reward, and it
is not established whether animals trade off other preferred stimuli in
similar ways. Here, we offered female guppies (Poecilia reticulata) a
spatial discounting task in which we measured preferences for a larger
reward as the distance to it increased relative to a closer but smaller
reward. We tested whether the fish discounted reward types differently by
offering subjects either food items or same-sex conspecifics as rewards.
Before beginning the discounting tasks, we conducted validation tests to
ensure that subjects equally valued the food and social stimuli in the
quantities provided. In the discounting task, subjects switched their
preferences from the larger to the smaller reward as the distance to the
larger reward increased (spatial discounting), but the pattern and
magnitude of discounting did not differ across the two reward types. These
findings indicate that guppies show similar patterns of discounting food
and social rewards in a spatial task. In an analysis of travel times,
however, the fish swam faster to food rewards than to shoaling partners.
This difference in travel times implies that fish temporally discounted
social rewards less steeply than food rewards. Thus, reward type
influences temporal discounting, suggesting a dissociation between
temporal and spatial discounting. Our results illustrate how animals
adjust choices and travel times depending on both the type of cost (time,
distance) and benefits (food, social partners).