This interesting article was published in the Garden News under pests and diseases, by Stefan Buczacki.

GARDENERS who have suffered damage from rabbits would willingly swap a single one for a million aphids The amount of damage these small, furry creatures can do in half an hour is out of all proportion to their size, and it's hard now to believe they once suffered the most catastrophic decline in numbers of any mammal in the history of the British Isles

Cause
Many people still think of rabbits as rodents - relatives of rats and mice - but they aren't even related. Along with hares and a small group of creatures called picas, they are known as lagomorph's - a family of herbivorous mammals with fur, long ears and long back legs and an ability to run very fast.
At one time, it was the custom to blame the Romans for their introduction into Britain, but it's now known rabbits were brought here from their native Spain and Portugal by the Normans as a source of food.
They clearly liked what they found because by 1950 there were about 100 million rabbits in Britain - probably our most numerous mammal ever. Then they were struck down by myxomatosis, which reduced their numbers by 95 per cent. But back they came and they are now numerous again - and threatening gardens everywhere.

Identification
Rabbits nibble and graze a vast range of wild and cultivated plants they eat young shoots and leaves, strip the bark from young trees - especially in severe winters when other types of food are scarce - and feed on flowers, fruits and seeds.
In gardens, almost anything is likely to be eaten. But among the plants they seem to go for first are lettuces, hostas, heathers and lilies, although many herbaceous perennials are also susceptible to attack and may be seriously damaged in spring and early summer.

How it works
Rabbits are burrowing animals, living in tunnels excavated in hedge banks, under thickets of hawthorn and bramble and in similar locations.
They mainly emerge from their burrows at night to feed on plants Each rabbit eats about 500 g (1 lb) of green matter each day, so large colonies have a marked effect on vegetation near their warrens.
Each female produces between two and four litters a year, mostly between January and June, and each litter contains from three to six young rabbits.
They mature and start to breed within a year, which is why populations increase so rapidly. This high reproductive potential may be checked by predators, such as foxes and weasels, and more recently by buzzards, which seem to prefer rabbits to anything else
Their numbers can also be affected by diseases such as myxomatosis This virus was introduced into Europe from South America and was initially very virulent. Fleas and mosquitoes transmitted it from unhealthy to healthy rabbits and populations were rapidly reduced. In Britain, they almost disappeared and in 1955 it was estimated that the value of cereal crops had increased by £15 million as a result.
Since then, the disease has become less virulent and numbers have increased again, although in some areas there may be an annual cycle with the disease reaching a peak in late summer and early autumn.
Future prospects
Without another outbreak of disease, I can see very little to prevent rabbits continuing to build up their number - but let's hope it doesn't reach 100 million again!