Rules of the roost: characteristics of nocturnal communal roosts of rainbow lorikeets (Trichoglossus haematodus, Psittacidae) in an urban environment

Abstract

Rainbow lorikeets (Trichoglossus haematodus) have successfully adapted to urban environments and are today abundant in many Australian cities. Here they often form noisy communal roosts and may damage infrastructure. While extensive studies on problem birds (mainly passeriforms) and their roosts have been conducted in other parts of the world, no detailed studies exist in Australia, where non-passeriform birds (e.g. parrots) can cause problems. This study investigates the roosting preferences of rainbow lorikeets in Sydney (Australia) and establishes the site characteristics that typify these roosts. Lorikeets preferred three exotic tree species, namely the plane tree (Platanus spp. including Platanus x hybrida), Canary Island palm (Phoenix canariensis) and Norfolk Island pine (Araucaria heterophylla). They were also common in brush boxes (Lophostemon confertus), a tree native to Queensland, Australia. Rainbow lorikeets commonly roosted in tall trees with thick trunks and medium density foliage and the trees next to their roost trees were of the same species. Roosting trees were often in areas of high anthropogenic disturbance and close to streetlights.