The feeding ecology of Rüppell's Parrot, Poicephalus rueppellii, in the Waterberg, Namibia

Abstract

Rüppell's Parrot, Poicephalus rueppellii, inhabits a markedly seasonal environment in Namibia and feed on plant seeds that respond to that seasonality. Although Rüppell's Parrots were seen feeding at 37 plant species they showed clear preferences. The diet was dominated by seeds, but also included other fruit, flowers (especially nectar), leaves, arthropods and bark. The arthropods were the larvae of lepidoptera, coleoptera and hemiptera, and spiders. Feeding was observed on 19 plant species during a year period and the proportion of observations/species/month was determined. Terminalia prunioides, Albizia anthelmintica and Acacia er/o/oba represent preferred foods and provided most of the diet at particular times of the year. The fruiting periods of most plants were highly seasonal and the parrots changed diet frequently; however, T. prunioides holds its pods all year round and was used more than any other species. Monthly diet was also analysed by food type. Seeds formed the greatest part of the diet from December to August, but flowers and insects formed a major part of the diet prior to the onset of the rains. In particular, A. anthelmintica provided nectar and harboured insects when there was very little other food available. It may be critically important in the east of this parrot's distribution where the winter-fruiting Faidherbia albida is not found. For two species there Was some evidence that soft, slightly unripe drupes were preferred over riper, harder fruits. Rüppell's Parrot is omnivorous but mostly a seed predator. It survives in a highly seasonal environment by exploiting a wide range of food items.