Colonisation of a site by despotic bell miners: dispersal, establishment and diversity influences of banded birds

Abstract

The bell miner (Manorina melanophrys) is a despotic honeyeater. Little is known about permanent colonisation in this species. Our banding study aimed to document changes in species richness over time and capture the effect of a despotic species. Our study is the first to document individual movements that led to the establishment of two permanent breeding colonies over 22 years of banding. One site in the Australian Botanic Garden, Mount Annan where birds moved in, compared to Camden Airport where bell miners have been present since the mid-1950s. Over the first 12 years there were three short-term visits by small groups of bell miners into the Conservation Woodland Area, in the Australian Botanic Garden, Mount Annan, for a maximum of three months. Retrapping of individuals showed that birds were first-year and older and travelled 2.1–4.2km. In 2016, both colonies contained over 120 birds and species richness changed, particularly of canopy-foraging species. At the Australian Botanic Garden, Mount Annan, 18 bird species decreased in number, with three no longer present (F33,34=2.50, P=0.00). Two other species also colonised the area and 13 increased in number. Understorey species such as the satin bowerbird, the eastern spinebill and the superb fairy-wren increased significantly. Movements of 0.3–1.0km were also detected at the Camden Airport site. At Camden Airport, five species decreased in number and four species increased but species richness stayed the same. Interestingly, bell miners decreased in number. After a heat wave in Summer 2016/17, bell miner weights declined and the colony disappeared. No eucalypt defoliation was observed in November 2017. Understorey modifications occurred only in areas away from the study sites during this project, suggesting that weather and food resources are the main contributing factors to colony establishment and longevity.