‘Hitchhikers a threat to wildlife’

WILDLIFE from red squirrels to earthworms and juniper trees are among those most at risk from invasive species, conservationists have warned.

Experts are calling for strict government plant import restrictions and want gardeners to “buy British” to avoid bringing in new invasive species that could threaten more of Britain’s nature.

Wildlife and Countryside Link, a coalition of nature groups, has released a list of the 10 native species it considers most at risk from invasive plants, animals and fungi through disease, competition or being eaten.

The list contains well-known species such as the red squirrel, which has suffered a 96% drop in numbers since its grey cousin was introduced from America in the 19th century, and water voles, lost from 94% of their range due to predation from American mink from fur farms.

It also includes the common earthworm, which is being preyed on by New Zealand flatworms that were introduced to the UK through imported potted plants, soils and compost, and the freshwater shrimp which is under threat from “killer shrimp”.

Native oysters, white-clawed crayfish, depressed river mussels and even Manx shearwater – whose populations are threatened by brown and black rats on their island homes – are also on the list of those most at risk.

Juniper – one of the UK’s rarest trees and a key ingredient in gin

– is threatened by the fungus-like pathogen Phytophthora austrocedri, while ash trees are being hit by ash dieback caused by a non-native fungus.

Both are thought to have arrived through the plant trade and the conservationists warned horticulture is a key route for importing some non-native species.