is now dispersed across Queensland. Movements of grey-headed flying foxes are influenced by the availability of food. Their population is very fluid, as they move in response to the irregular blossoming of certain plant species. They are keystone pollinators and seed dispersers of over 100 species of native trees and plants. The grey-headed flying fox is a partial migrant that uses winds to facilitate long-distance movement. It does not migrate in a constant direction, but rather in the direction that will be the most beneficial at the time. Although recorded in small numbers sporadically throughout the 20th century, it was not until the 1980s that grey-headed flying foxes routinely visited Melbourne, with a permanent camp since the 1990s. Their residence at the Melbourne Botanic Garden was the subject of controversy, and the bats were eventually discouraged and moved to Yarra Bend at the city's river. The camp at this site was decimated during a heat wave, requiring its rehabilitation to sustain the relocated population. The forced relocations are also said to have led to the discovery of the orchards of the Goulburn Valley. Similarly, the first recorded permanent camp in Adelaide was established in 2010. The spread is likely due to global warming, habitat loss and drought; while the location of the new camps appears to be in response to urbanisation: a reliable food supply (such as native eucalypt plantings and backyard fruit trees) and warmer temperatures due to climate change and urban heat islands. Diet and foraging Around dusk, grey-headed flying foxes leave the roost and travel up to 50 km a night to feed on pollen, nectar and fruit. The species consumes fruit flowers and pollens of around 187 plant species. These include eucalypt, particularly Corymbia gummifera, Eucalyptus muelleriana, E. globoidea and E. botryoides, and fruits from a wide range of rainforest trees, including members of the genus Ficus. These bats are considered sequential specialists, since they feed on a variety of foods. Grey-headed flying foxes, along with the three other Australian flying fox species, fulfill a very important ecological role by dispersing the pollen and seeds of a wide range of native Australian plants. The grey-headed flying fox is the only mammalian nectarivore and frugivore to occupy substantial areas of subtropical rainforests, so is of key importance to those forests. The teeth, tongue and palate of the pteropodid bats are able to extract plant juices from food,