Country & Garden: Nature Notes

MYXOMATOSIS IS back. After lying dormant for much of the year, the viral infection almost always strikes rabbits again at this point in the autumn. The disease originated in South America, and was deliberately introduced into Australia and Europe as a means of controlling rabbit numbers. When it first reached this country, in 1954, the epidemic wiped out 99 per cent of the population, reducing it from an estimated 100 million to only one million. Since then, however, some rabbits have developed an immunity, so that a good many survive each new outbreak.

The viral infection is transmitted by fleas, and the symptoms are distressing: the rabbits' eyelids fill with pus and swell up until the victims can no longer see. They then blunder about, running headlong into fences or undergrowth, unable to find their burrows. Although they continue to eat, they grow thinner and thinner, until they are skin and bone, finally dying. After each epidemic, the predators that normally live on rabbits - foxes, stoats, buzzards - survive by switching to other forms of prey such as voles until the population builds up again.

Duff Hart-Davis