The lemurs’ food preferences correlated significantly with the content of carbohydrates and sucrose but not with the total energy content. This suggests that ring-tailed lemurs are not opportunistic feeders with regard to energy gain but rather seek to meet their requirements of metabolic energy by preferring foods that are high in soluble carbohydrates

Ring-tailed lemurs have been reported to be one of the most adaptable and ecologically flexible lemur species with the ability to adjust to food resource seasonality. Due to their dietary flexibility they are able to consume a wide variety of foods and even poor-quality food items. Lemur catta has a slower gut passage time than other, more frugivouros lemur species, such as Lemur fulvus or Varecia variegata, and they have a more developed gastrointestinal tract to deal with plant fiber. Even though free-ranging lemurs have shown a high degree of adaptability to different habitats and thus to different compositions of available food they still seem to aim at optimizing their intake of carbohydrates and sugars. 

The food preferences of the lemurs in this study did not significantly correlate with the content of protein in any of the food items. The items with the highest protein content were mealworm and egg. Meal worm were not preferred over any if the items, but egg were preferred over six items. Wild ring-tailed lemurs can catch and consume insects but it is not seen in all populations.

Comparatively little is known about the importance of lipids as macronutrients in the diet of primates. One possible reason for this may be that plant material consumed by non-human primates only rarely contains amounts of lipids that would markedly contribute to the ingested total energy of a primate. Animal matter consumed by primates, in contrast, may contain considerable amounts of lipids but information as to the lipid content of e.g arthropods consumed by primates in the wild is sparse.

The results of the present study show that the lemurs’ food preferences did not correlate with the content of water. This should not be surprising since wild ring-tailed lemurs do not depend on finding water-rich food items to meet their water requirements, but have been reported to regularly drink from open water sources. The lemurs in the present study were always provided with ad libitum fresh water from a drinking bowl.

The food preferences of the lemurs in the present study did not correlate with the content of any of the micronutrients considered. Since Lemur catta eat soil to meet their sodium requirements it was interesting to assess if their food preferences correlated with sodium content in the food items. No significant correlation was found, and this can be an indicator that the lemurs’ diet contained enough sodium to meet their need for it.

It is well-established that animals may display marked preferences for certain micronutrients if their diet is lacking them or if the diet contains too little of them over a prolonged period of time. Animals then often develop a craving for food items that contain the missing nutrient. The finding that the lemurs did not display any significant preferences for any of the micronutrients that were included in the analyses in the present study, suggests that the diet fed to the lemurs was balanced so that the lemurs did not need to compensate any nutrient deficiencies by displaying preferences for food items that contain high amounts of the deficient micronutrient. 

Even though the lemurs in the present study showed marked food preferences for fruits with high levels of carbohydrates and sucrose this does not mean they should be provided with a diet high in carbohydrates. However, the results of this study imply that ring-tailed lemurs have a strong preference for carbohydrate-rich fruits and vegetables which at least needs to be considered when composing the diet for zoo-housed lemurs. Since vegetables such as cabbage, cucumber, tomato and eggplant were nearly never eaten, the more carbohydrate-rich ones such as sweet potato and carrot can be used. 

The results of the present study show that zoo-housed ring-tailed lemurs display marked food preferences, when presented with 12 different food options, in relation to nutrient composition. The lemurs’ food preferences correlated significantly with the content of carbohydrates and sucrose. The food preferences did not correlate with any of the other macro- or micronutrients.  Due to the low number of tested individuals the results of the present study preclude more generalizing conclusions about food preferences in zoo-housed lemurs. The knowledge about animals’ food preferences might give important information on how to improve their welfare in zoos.