RHD Virus Reduces Rabbit Population in Australia
A new rabbit-control virus has so far been successful in drastically reducing the number of European rabbits in Australia. In the 1950s, the myxomatosis virus temporarily reduced rabbit numbers, but over time, the rabbits developed resistance, and myxomatosis no longer is effective in reducing population size. The new virus, called rabbit hemorrhagic disease (RHD), has reduced rabbit populations by 95% in some places. Biologists report that in some areas, they used to observe that 85% of the dung came from rabbits, and now 60% of its comes from kangaroos. Also, native species of plants and animals are returning to areas and increasing in numbers.

Of course, many fear that somehow the virus may spread to other species, and maybe even humans. So far, that has not occurred. Another impact may occur in the populations of predators that prey upon the rabbits. One such population, feral cats, has already declined, but biologists cannot be certain yet if this is a response to the decline in rabbits or to other factors. Biologists continue to use other rabbit-control tactics in conjunction with RHD, and it is unclear if the rabbits will be able to develop resistance as they did with myxomatosis.

"Wide Use of Rabbit Virus Is Good News for Native Species," by Dan Drollette, Science, vol. 275, page 154, January 10, 1997