Feeding Ecology of Fruit Pigeons in Subtropical Rainforests of South-Eastern Queensland.

Abstract

In a 5-yr (1979-84) study of 6 species of fruit pigeon in lowland (dry) and upland (wet) subtropical rain forests in the Jimna and Conondale Ranges, the effects of forest phenology on pigeon abundance were investigated. The pigeons utilized 89 species of plants from 39 families of trees, palms and vines. The seasonal availability of fruit was similar in each forest type: most plant species bore crops during the wet season (Dec.-Mar.) and held crops into the early dry season (April-May); the late dry season (June-Oct.) was a time of general fruit shortage. More than 60% of the species of food plants present in upland forest were rare or absent in lowland forest. In general, each species of pigeon utilized a distinct suite of plant species in each forest type. Certain species of fig (Ficus spp.) fruited asynchronously and were the most important food for sedentary wompoo fruit-doves (Ptilinopus magnificus magnificus) in both forest types. These and other species of fig were the most important food for topknot pigeons (Lopholaimus antarcticus) and rose-crowned fruit-doves (P. regina regina) in lowland forest. An influx of flocks of up to 200 topknot pigeons into upland forest occurred each year in response to the fruiting of Archontophoenix cunninghamiana. The foraging habits of rose-crowned fruit-doves were largely opportunistic in upland forest, utilizing whatever fruit was available at particular times. White-headed pigeons (Columba leucomela) foraged solely in Olea paniculata during irregular visits to lowland forest. A regular summer influx into upland forest occurred in response to the fruiting of a vine, Piper novae-hollandiae. In each forest type, brown cuckoo-doves (Macropygia amboinensis) had a distinct foraging preference for plant species characteristic of disturbed forests; important plant families were the Solanaceae, Ulmaceae, Euphorbiaceae and Araliaceae. Superb fruit-doves (P. superbus) were seldom found in either forest type.