Leaf-slicing behavior in the Blue-headed Parrot (Pionus menstruus) in central Amazonia is likely linked to highly selective caterpillar predation

Although they eat seeds, pulp, petals, pollen, and nectar, parrots are rarely recorded as eating leaves, with only one species being fully folivorous. In terra firme forest in south-central Brazilian Amazonia, we recorded apparent folivory over a several sequential days by the Blue-headed Parrot (Pionus menstruus) on young leaflets of Swartzia polyphylla (Fabaceae). Closer examination, however, showed that the majority of processed leaves also contained small caterpillars, so that we consider this to be a record of highly selective insectivory, which is also uncommonly reported in parrots. We speculate that such events may be more common than realized and act as dietary supplements for a seed-based diet.