Kill the Bunnies!

Australia has a serious rabbit problem, and the government had to resort to biological warfare to combat the ecological devastation caused by the rabbits.  Wild rabbits were introduced into Australia in 1788, and the population soon exploded into the hundreds of millions.  This pest was not only the most significant factor in species lost, but also contributed to the erosion of topsoil–which takes hundreds of years to replace.  There have been many successful efforts to control the rabbit population, but biological measure peaked my interest.

The myxoma virus was introduced to the rabbit population in 1950, and was massively successful, reducing the estimated rabbit population from 220 million to 10 million. The myxoma virus causes rabbit hemorrhagic fever, and is a double stranded DNA virus in the Poxviridae–the same family as the smallpox virus that decimated human populations. 

Image credit: Saunders et, al. 

Although this virus was massively successful, it did not eliminate the rabbit population, and the resistant rabbits that remained approached 100 million by the 1970’s. Rabbit fleas were introduced as a vector to enhance the spread of the virus, which helped to reduce the rabbit population again, but alternative biological control measures will need to be used for the foreseeable future as the rabbit-virus arms race develops.

Infected rabbit: Image credit Wikipedia

-Cynthia Taylor

Source:

 Saunders, Glen, Brian Cooke, Ken McColl, Richard Shine, and Tony Peacock. 2010. “Modern                              Approaches for the Biological Control of Vertebrate Pests: An Australian Perspective.”                      Biological Control 52 (3): 288–95. doi:10.1016/j.biocontrol.2009.06.014.