Preference of supplemental nectar by three native butterfly species

Two diets, a sugar-water solution (Diet A) and nutritionally complete nectar solution (Diet B), provided in a mixed species enclosure as a source of nutrients for multiple nectivorous species were evaluated for preference among three North American species of butterflies. Preference was defined as number of visits to one of two nectar feeders. The feeder containing Diet B was preferentially...

Comparative protein requirements of three species of parrots with distinct dietary specializations

Highly specialized nectarivorous and frugivorous birds have overcome the constraints of low dietary protein levels. Proposed physiological mechanisms that enable such specialists to subsist on low-protein diets include low protein requirements, low endogenous protein losses, high feed intake, and high protein digestibilities. These traits were compared among nectarivorous red lories (Eos bornea), frugivorous Pesquet’s parrots (Psittrichas fulgidus), and granivorous budgerigars...