Predator-proof fence helps Cumbrian gull colony bounce back

The number of gulls nesting and fledging at a Cumbrian nature reserve has risen by 150% following the installation of a predator-proof fence.

South Walney Nature Reserve – once home to Europe's largest gull colony – saw numbers drop significantly by 2020, to the point that Cumbria Wildlife Trust was concerned the birds were in danger of vanishing completely. Counts of European Herring and Lesser Black-backed Gull had fallen due to increased predation by foxes and badgers, so the Trust installed a predator-proof fence to protect chicks in a 7.5-ha area.

European Herring Gull has thrived at South Walney since the anti-predator fence was erected (John Lauper).

The installation of the fence has turned the situation around. In 2021, chicks fledged for the first time in over a decade. Last winter, the fence was heightened and strengthened, and resulted in a bumper 2022 breeding season.

A spokesperson said: "This year, not only did more chicks fledge, but the number of gulls nesting at South Walney increased beyond expectation, from 449 pairs (the lowest since the 1950s) to 1,128 pairs, a stunning 150% increase."

Paul Waterhouse, Reserves Officer at Cumbria Wildlife Trust, added: "This is great news for the gull colony at South Walney. It's the largest percentage increase recorded at the colony since the population explosion in the 1950s. The gulls have been attracted back to the site by the successful fledging of chicks last year. Let's hope this important colony continues to go from strength to strength."

Sarah Dalrymple, coastal species and habitats officer at the RSPB, commented: “Although it often doesn't feel like it when so many of them nest in our towns and cities, European Herring and Lesser Black-backed Gulls are in fact in severe decline. South Walney is one of the most important natural nesting sites for these birds in England, so seeing the numbers recovering so quickly after putting up the fence is brilliant news."