Current strains of myxomatosis are far more virulent than that released in 1950, but rabbits have increased resistance as well. Nonetheless, myxo is still important for rabbit control in Australia, and new bio-controls shouldn’t be considered if they would reduce its effectiveness. That is one of several conclusions from a 50 year review of European rabbit fleas and myxomatosis in Australia, published in Wildlife Research.
Other observations are:
- Myxomatosis transmitted by European rabbit fleas kills young rabbits in winter and early spring, resulting in less grazing pressure and more good quality feed later in the season.
- High protein food allows effective late season breeding with enough young surviving to maintain the next generation.
- Rabbits can develop genetic resistance, yet viruses may develop greater virulence and maintain mortality rates.
Brian Cooke, author of the review, also developed a conceptual model of how rabbit numbers, the relative virulence of myxomatosis, and the availability of good early summer feed were related.
For more information:
- The Wildlife Research (July 2022) paper by Brian Cooke; ‘A fifty-year review of how European rabbit fleas enhanced the efficacy of myxomatosis for controlling Australian Rabbits’.
- A summary of Brian’s paper by Rabbit-Free Australia; ‘Rabbit abundance. A dance between myxoma virulence, rabbit resistance and summer feed’.