Pole position: social influences on discounting behaviour in wild grey squirrels

Extensive laboratory studies have shown that animals strongly devalue rewards with associated costs, such as time or effort. However, these laboratory discounting tasks have limited ecological validity, whereas in natural decision-making scenarios, animals may wait or expend more effort for a substantially better outcome. In our experiment, a discounting task in which wild grey squirrels, Sciurus carolinensis , in their natural habitat chose between climbing a short distance to receive a less preferred food or a longer distance to receive a preferred food was used. The squirrels exhibited relatively shallow discounting, slightly devaluing their preferred food with the increase of distance, compared with the steep declines observed in laboratory-tested animals. Social effects were also observed where less dominant squirrels showed steeper devaluation of the preferred food, which may be due to an increased risk of losing the reward as distance increased. Separately, squirrels were more likely to climb a longer distance in the presence of conspecifics, perhaps choosing the more time-consuming and effortful option to avoid increased competition for the easier, more immediate reward. The findings of this study indicate that understanding animals’ decision-making behaviour requires more ecologically valid approaches, such as considering the social context in which choices are made. • Grey squirrels show relatively shallow discounting in an ecologically relevant task. • Subordinate squirrels showed steeper discounting. • Squirrels exhibited shallower discounting in the presence of conspecifics.