Eatherley’s convivial, matey style of prose may not be to everyone’s liking, but Invasive Aliens provides a well-researched overview of this complex and controversial topic. There is plenty here to surprise as well as enlighten. For example, in 1890, the chairman of the American Acclimatisation Society, a German immigrant called Eugene Schieffelin, released sixty European starlings in New York City’s Central Park. This was part of an eccentric scheme to populate the continent with every sort of bird mentioned in the plays of Shakespeare. Starlings, which feature in Henry IV, Part 1, are now North America’s most abundant bird and devour an estimated $750 million worth of agricultural produce every year.
Eatherley’s narrative abounds in such unintended consequences. In the Fifties, Mao Tse-tung declared war on sparrows, as an agricultural pest, but their eradication led to plagues of locusts and famine, and they had to be reintroduced from the Soviet Union. In 1890, Eugene Schieffelin, chairman of the American Acclimatisation Society, released 60 starlings into Central Park in New York, as part of a scheme to populate North America with all the birds mentioned in Shakespeare. They are now the continent’s most abundant bird, numbering about 200 million, blamed for eating $750 million (£600m) worth of agricultural produce annually, for transmitting gastroenteritis to farm animals, and for bringing down aircraft by clogging their engines.
...what you realise, as you read this fascinating book, is that there is probably nowhere on our sceptred isle that is immune from incomers. The entire countryside is a Brexiteer’s botanical nightmare and has been for a very long time...Eatherley has the unflagging curiosity of a Victorian explorer. The man seems to be indefatigable as he hacks away at Himalayan balsam (the pink, flowery weed that lines almost every riverbank in Britain) or goes on patrol for invasive signal crayfish in the River Barle. He’s not afraid to get wet, dirty or tired on his mission to get up close and personal with intruders of all shapes and sizes. It feels as if we are on the front line with him.
The story of invasive species is often one of accidental introduction. Or of misguided humans who think they are somehow setting a creature ‘free’ — like the group of Buddhists who released hundreds of foreign lobsters from a boat off the English coast in 2015 as part of a religious ceremony. (They were later fined £15,000 for environmental damage, and extensive efforts were made to recover the crustaceans.) Or even more humbly, those who put their goldfish in a local stream — helping to contribute to the population of invasive fish. (In tanks, goldfish remain small, but set free they can grow to weigh several pounds.)