Title
Diet of the Atlantic forest maned sloth Bradypus torquatus (Xenartha: Bradypodidae)
Document Type
Article
Publication Date
2006
Volume Number
246
Source Publication
Journal of Zoology
Abstract
The diet of maned sloths was studied throughout 14 months in an Atlantic forest reserve of south-eastern Brazil. Three adult sloths were observed for a total of 680 h and located monthly by radio-telemetry. Data were collected on diet, recording the actual time the sloths spent eating plant species. Overall, the diet was composed of 99% leaves, with young leaves (68%) preferred to mature ones (7%) throughout the year. A higher proportion of tree leaves (83%) than liana leaves (16%) were included in the diet. When analysed together, the diet of the three animals included a total of 21 plant species (16 tree and 5 liana), but each individual made up its diet with an even smaller number of species (7–12) and with a particular subset of the local flora. This is a very small portion of the total number of tree and liana species available to the sloths; furthermore, the top species consumed were present at very low population densities in the forest. Thus, B. torquatus, like other congeneric species studied elsewhere in the Neotropics, is a strictly arboreal folivore with a highly selective diet, probably resulting from evolving physiological adaptations to cope with a smaller range of plant secondary compounds. This is possible for the species of this genus through a combination of low basal rates of metabolism, which enable the sloths to survive on an energy-poor diet, and a very long passage time of digesta, which, in turn, aids the digestion of a fibre-rich diet while possibly contributing to the degradation of secondary compounds.