Digestibility of palm seeds and bruchids larvae by Neotropical rodents

Vertebrates show different tendencies in regard to their preference for seeds or fruits infested by insects compared to non-infested ones. Behaviour may include rejection of one type, preferential consumption of one type or no differentiation among them. When comparing infested versus non-infested fruits, most studies have focused on energy content and nutritional components of the food items; but the energy input provided to the consumer is a better measure for the comparison of the value of each type of food. In this study, I calculated the energy assimilated by rodents for the seeds of the palm Attalea butyracea contained in non-infested endocarps and from bruchid beetle larvae contained in infested endocarps. Using the energy assimilation and time of handling by rodents for both types of endocarps, I quantitatively demonstrated that both infested and non-infested endocarps produce a similar energy input. This finding is consistent with the previous hypothesis that there is a trade-off between the energy content and the time required to extract the insect larvae compared with the seeds in endocarps of Attalea butyracea. (C) Koninklijke Brill NV, Leiden, 2011.