Numerical discrimination by non-human animals has traditionally been studied in primates, birds and rats. However, a recent study (Uller et al. 2003, Animal Cognition 6:105-112) found that the red-backed salamander (Plethodon cinereus) would "go for more" prey during a forced-choice discrimination task, selecting the larger of two numerosities in 1 versus 2 and 2 versus 3 trails, but did not distinguish between 3 versus 4 and 4 versus 6 prey items. These results agreed with studies of other animals choosing between numbers of food items, suggesting that P. cinereus has a capacity to discriminate among certain small numerosities. Using an alternative experimental design, we tested the hypothesis that the horizontal spatial distribution of prey influences numerical discrimination in P. cinereus. Results indicate that salamanders significantly preferred to approach two prey items that were more distantly separated versus two that were closer in distribution. However, in choice tests of 2 versus 3 prey items, salamanders showed no significant preferences when the prey items in the two groups were separated either by equal inter-prey distances or by equal overall horizontal spread of the prey. Taken together, these results suggest that both the numerical quantity of prey and the spatial distribution of prey items help determine salamander choice preferences.