Analysis of bark eating in a tropical squirrel

Although bark eating is quite common among mammals, few species include it as a major item in their diet. The diet of the small squirrel Sundasciurus lowii on Siberut Island, Indonesia, consists mainly of bark. Physical characteristics, nutrient concentrations, and the presence of defense compounds were investigated in bark from 711, 13, and 57 food and nonfood trees, respectively. The results suggest that the squirrels select bark on large, smooth-barked trees with low levels of hydrolysable tannins, whereas concentrations of fat, crude protein, crude fibre, carbohydrate, and calorific value examined in a set of bark samples had no detectable influence on food tree selection.