Habitat loss is one of the greatest threats to Blyth’s flying fox, as the islands’ natural habitats are converted to agricultural land, developed for tourism-related activities, or subject to logging (1). Blyth’s flying fox may also be impacted by hunting, either for food or for traditional ‘medicines’ (1) (5).
The Christmas Island population of Blyth’s flying fox is considered to be the most threatened. Numbers of Blyth’s flying fox have declined drastically here – from an estimated 6,000 individuals in 1984 to about 1,500 in 2006. The exact reasons for this decline are not clear, but it is likely due to a combination of factors, including predation by feral cats and hunting for food (5). The yellow crazy ant (Anoplolepis gracilipes) has caused significant damage to the wildlife of Christmas Island since its introduction in the early 1900s. Yellow crazy ants may directly disturb, displace or kill Blyth’s flying fox, and they also affect its food supply, by reducing fruit production and even killing fruiting trees (5).
Climate change is likely to impact Blyth’s flying fox by affecting forest and wetland ecosystems (5). The Intergovernmental Panel on Climate Change (IPCC) expects that climatic changes will stimulate more extreme weather events, including higher temperatures, greater rainfall and increased frequency and severity of tropical cyclones (8) (9).Extreme weather events, such as tsunamis and severe cyclones, are likely to cause further damage to the habitat of this species, especially in coastal areas and on low-lying islands (1) (4) (9). It is thought that the population of Blyth’s flying fox on Enggano may have been wiped out by a severe hurricane (1).