When did grey squirrels start posing a threat to reds?

Grey squirrels first made their way to the UK in the 19th century, when a Victorian banker named Thomas V. Brocklehurst is believed to have released a pair of greys into Henbury Park, near Macclesfield in Cheshire, during a business trip from North America. Since then, their population has exploded, reaching between 2.5 million and 2.7 million in the country today.

Red squirrels, on the other hand, have dwindled from an estimated 3.5 million to fewer than 300,000 in the UK. In England, the Woodland Trust estimates there are just 39,000 reds left, while conservation groups estimate as few as 15,000 remain. Experts warn that red squirrels could vanish entirely within 25 years due to competition for habitat and food, as well as lethal diseases carried by greys.

The only viable solution currently is lethal control, such as shooting or trapping, though fertility control and pine marten reintroduction are being explored as potential additional methods.