Invasive Species on Islands
by glawrence21 on April 17, 2015 - 9:55pm
One of the biggest threats to biodiversity throughout the world is the introduction of invasive species. However, their detrimental effects are exaggerated on islands. The introduction of the brown tree snake (Boiga irregularis) to Guam is one of the most famous examples of an invasive species’ detrimental effects to a native island ecosystem. The introduction of this one species resulted in the population reduction of 22 of the 25 native bird species in Guam (Wiles et al. 2003). 12 native bird species were extirpated, and many species all but disappeared in less than nine years after the introduction of the brown tree snake (Wiles et al. 2003). The native species were not adapted to the predatory behaviors of the brown tree snake, and were only adapted to avoid predation by native predators, which led to their precipitous decline (Wiles et al. 2003). The impacts of the brown tree snake exemplify the effects of just one species on an island ecosystem. With the rapid introduction of non-native species that is outlined in Sax et al. (2002), the need for protection of native island-dwelling species is even more important.
Since there is a high abundance of endemic species on islands, and since many island groups are biodiversity hotspots, these habitats should be the number one conservation priority. The threats to the native species are dire and the effects could be devastating in short time, which means that action must be taken soon and be implemented quickly. Conservation of these unique habitats should be funded and supported immediately.
Sax, D. F., S. D. Gaines, and J. H. Brown. 2002. Species invasions exceed extinctions on islands worldwide: a comparative study of plants and birds. The American Naturalist 160: 766-783.
Wiles, G. J., J. Bart, R. E. Beck Jr., and C. F. Aguon. 2003. Impacts of the brown tree snake: patterns of decline and species persistence in Guam’s avifauna. Conservation Biology 17: 1350-1360.