A cautionary tale

This prompted by a review of reference 1 (report on which will follow in due course) in a recent number of the NYRB.

It seems that something called the rabbit calicivirus disease turned up in Europe in the early 1980’s and went on to kill several hundred million rabbits in China and elsewhere in very short order. I learn from reference 2 that it is properly called rabbit haemorrhagic disease or RHD, is very infectious and usually fatal within a few hours. Something similar affects hares.

It is now more or less endemic across the world, although Mexico managed to eradicate it and the US has it well under control – their native rabbits being much less susceptible than the imported European variety.

Contrariwise, in Australia and New Zealand, where rabbits are regarded as pests, they thought about deliberate introduction. The virus then escaped from an island experiment and went on to kill millions of rabbits in Australia in a few weeks. New Zealand decided against but got it anyway.

The good news is, first, that domestic and farmed rabbits can be immunised, various technical difficulties around this particular virus notwithstanding. And second, that there are now resistant strains of rabbits, and many wild populations are recovering. The bad news is that rabbits and virus are co-evolving, with the rabbits (in effect) trying to protect themselves and the viruses working out how to get through the new defences. Work in progress.

The worse news is that this sort of thing is going to happen from time to time, sometimes to humans, who can't restock as fast as rabbits, as we now know all too well.

PS 1: the snap, a catalogue of all the things that go wrong, is taken from reference 2.

PS 2: I learn from reference 1 that the fossil record suggests that the European rabbit originated in the Iberian Peninsula during the middle Pleistocene, say a million years ago or so. While I learned from the review in the NYRB that a million years or so is the average life span for a species of mammal.

References

Reference 1: The Precipice: Existential Risk and the Future of Humanity – Toby Ord – 2021.

Reference 2: Rabbit haemorrhagic disease (RHD) and rabbit haemorrhagic disease virus (RHDV): a review – Joana Abrantes, Wessel van der Loo, Jacques Le Pendu and Pedro J Esteves – 2012. There are accessible bits, but most of this paper is not accessible, being directed at virologists.

Reference 3: https://www.msdvetmanual.com/exotic-and-laboratory-animals/rabbits/viral-diseases-of-rabbits. The headlines.