Food preferences and nutrient composition in zoo-housed ring-tailed lemurs, Lemur catta.

The aim of the present study was to assess the occurrence of spontaneous food preferences in zoo-housed ring-tailed lemurs and to analyze whether these preferences correlate with nutrient composition. Using a two-alternative choice test three female and one male Lemur catta were repeatedly presented with all possible binary combinations of 12 types of food which are part of their diet in captivity and found to display the following rank order of preference: apple > sweet potato > melon > beetroot > carrot > egg > eggplant > pumpkin > cucumber > tomato > cabbage > mealworm. Correlational analyses revealed a highly significant positive correlation between this food preference ranking and the total carbohydrate and sucrose contents of the foods (p < 0.01, respectively). No other significant correlations with any other macro- or micronutrient were found. These results suggest that zoo-housed ring-tailed lemurs are not opportunistic, but selective feeders with regard to maximizing their net gain of energy as only the content of carbohydrates, but not the contents of total energy, proteins or lipids significantly correlated with the displayed food preferences. Further, we found that ring-tailed lemurs that were raised on a vegetable-based diet did not significantly differ in their food preferences, and in particular in their predilection for food items high in carbohydrates, from animals that had previously been fed a fruit-based diet. This suggests that the lemurs' preference for carbohydrate-rich food items may be innate and not affected by experience with different diets.