Showy birds on attractive food sources: rainbow lorikeets and their plant-related functions at a residential area in South-eastern Australia

Lorikeets (Psittaculidae: Loriinae) are characterised by their brush-like tongue used to lap nectar and gather pollen from flowers. Lorikeets also feed on fruits, seeds, lerps, and insects. Some species, such as rainbow lorikeet Trichoglossus moluccanus adapted well to urban and suburban areas. These lorikeets exploit flowers and fruits from trees and shrubs used in gardening and landscaping as food source. We report herein on the diversity of plant species used by rainbow lorikeets in a small residential suburban area in South-eastern Australia. We found that the lorikeets use 20 plant species as sources of nectar and/or pollen, fruits, and seeds. While visiting the diverse flowers, pollen adhered to different parts of the lorikeets’ body, the birds acting as potential pollinators. In the case of figs, the lorikeets ate both the fleshy portions and seeds, acting as seed predators. When the minute fruits adhered to the birds’ bill and chin or were swallowed along with the pulp, the lorikeets acted as potential dispersers. Seed predation also occurred when the birds extracted seeds from she-oak and grass fruits. On night-blooming plants, the lorikeets acted mostly as supplementary pollinators, flying foxes being the main pollinators. The lorikeets retained their functions as potential pollinators and dispersers, and delivered ecosystem services even within a highly human-modified environment. Our suggestion about the diurnal lorikeet’s role as an auxiliary pollinator of night-blooming plants pollinated by mammals, and its role as main pollinator where or when these mammals (mostly flying foxes) are missing, would also be played by other bird species such as honeyeaters (Meliphagidae).