| adaptations for avian frugivory: assimilation efficiency and gut transit time of manacus vitellinus and pipra mentalis. | i examined the digestive physiology of two avian frugivores, the golden-collared manakin, manacus vitellinus, and the red-capped manakin, pipra mentalis, to discover how these birds extract energy from fruit. using 14 species of fruit in the natural diet of manakins, i examined the assimilation of nutrients from fruit pulp, fruit passage rates, seed passage rates, and gut morphology. fruits in the manakins' diets had high water content (average, 84%) and low nutrient concentrations (3 kj/g wet p ... | 1989 | 28312066 |