Rainbow Trichoglossus haematodus and Musk Glossopsitta concinna Lorikeets have increased in abundance in Melbourne, Australia in recent years. We documented the diet and feeding behaviour of these lorikeets at 20 parkland sites in autumn and winter to increase our understanding of factors facilitating this urban colonisation. Both species’ diets were dominated (≥89%) by nectar and/or pollen of eucalypt species, more than two thirds of which were not native to the Melbourne area. Small numbers of invertebrates and some fruit and seeds were also consumed. Two or three of the eucalypt species used were flowering at any given time and two of the most exploited species flowered almost continuously. Introduced eucalypts have probably been important in the recent winter increase in abundance of the lorikeets in Melbourne. Both lorikeets used the same five feeding postures, perching upright (~58%) and dexterously hanging inverted (~ 40% of records) being the most common. Six other Australian native bird species exploited the lorikeets’ eucalypt nectar resources, but mostly infrequently; however, they did use the same foraging substrate and exhibit similar feeding behaviour. Only 11 aggressive inter-specific interactions involving the lorikeets were observed in 4.5 months. Significant interference competition from other bird species for the lorikeets’ highly abundant food resources seemed unlikely; its absence could also be facilitating the lorikeets’ winter colonisation of the city. Planting more eucalypts in streets and parks, including ones native to the Melbourne area, could potentially lead eventually to further increase in lorikeet densities in the city in autumn and winter.