They were introduced to Britain by the Romans, are hated as pests and celebrated in children's books. Britain's estimated 40m rabbits cost the economy more than £260m a year including damage to crops, businesses and infrastructure, a report says today.
Their near 2,000-year survival as a non-native species makes them the costliest natural invader, according to research for the English, Scottish and Welsh governments by CABI, the international agriculture and environment organization, whose work is focused around combating invasive plants, micro-organisms and insects wherever they are posing a threat. CABI works with countries to help them prevent importing or exporting invasive species and manage the species already present.
Japanese knotweed (left), introduced in the mid-19th century as an ornamental garden plant, has had far less time to rack up its own costly threats to the economy as it colonizes roadsides, riverbanks and derelict land.
The total cost of such invasive species now reaches £1.7bn a year, mostly to the English economy, more than £250m in Scotland and £133m in Wales.
But the report also provides justification for the high costs of controlling non-natives. It is estimated that the current eradication program for water primrose (right), a group of South American aquatic weeds which grow rapidly and can block waterways, will cost £73,000 – significantly less than the estimated £242m it would cost if the weeds were to become widely established as they have in in countries including France and Belgium.
Eradicating the grey squirrel (left), the North American 19th-century import which has put the native red in peril, may no longer be possible, the report concedes. An attempt to remove the species from Anglesey alone has so far cost £440,000. A conservative estimate puts the cost of a similar program across Britain at £850m.
Even that would be relatively small if the Asian long-horned beetle (right), a wood-boring menace from Japan, Korea and China, and now threatening North American trees, became established in this country. The report suggests it would cost over £1.3bn to remove it from hardwood forests alone, let alone clear it from parks, gardens and hedgerows.
Richard Benyon (below left), minister for the natural environment, said: "Invasive non-native species have a significant impact on the British economy and damage our own wildlife. The costs of controlling these species will rise unless society takes steps to prevent them taking hold and spreading."
"It becomes increasingly difficult and costly to control invasive non-native species as they become more established. Taking early action may seem expensive, but this report shows that it is the most effective approach, saving money in the long run and helping our native wildlife to thrive."
Roseanna Cunningham (right), Scottish minister for environment and climate change, said: "A better understanding of the negative impacts of invasive non-native species can help us raise awareness to help prevent introductions in the first place and to better respond to problems."
The Guardian, "Rabbits named Britain's most costly invasive species", accessed December 15, 2010