Food sources of the Rainbow Lorikeet Trichoglossus haematodus during the early wet season on the urban fringe of Darwin, Northern Territory

The food sources of the Rainbow Lorikeet Trichoglossus haematodus were studied from October to January in a mixed environment of urban, semi-urban and remnant native vegetation on the coastal fringe of Darwin in the Northern Territory. The study coincided with a period of low nectar availability in the tropical savannas, but abundant flowering and fruiting of rainforest trees and the ripening of cultivated fruit of Mango Mangifera indica. Lorikeets obtained a diversity of food types from 37 species of plants. Consumption of seed, mostly of the Coastal She-oak Casuarina equisetifolia, and nectar and/or pollen from a diversity of species comprised 41 per cent and 40 per cent respectively of foraging observations. Lerp obtained from the leaves of cultivated eucalypts was also prominent in the diet, whilst consumption of fleshy fruits was minor and consisted entirely of consumption of mango early in the study period. Just over 50 per cent of flower-feeding records were at eucalypts and over 60 per cent at myrtaceous trees. Food sources and flock sizes varied considerably over time within the study period. The median size of feeding flocks was five, with a range from 1 to 30, the largest flocks occurring in Mango trees and at the flowers of woodland trees, and the smallest at cultivated flower and leaf sources. Coastal forest provided mainly seed and woodland trees mainly nectar and/or pollen, whilst the urban environment provided a wide range of resources. However, an extensive band of semi-deciduous vine-thicket provided few food resources and supported few lorikeets during the study period. The large population of lorikeets in the study area was supported both by the diversity of plants associated in particular with urban plantings, and by the juxtoposition of habitats.

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