Measures Approved to Reduce Feral Geese Population

Measures aimed at controlling the number of feral geese at a popular Jersey nature site have been given the go-ahead.

The proposals were put forward by the Government of Jersey Department of the Environment’s biosecurity team and focus on reducing the breeding success of geese nesting at Grouville Marsh.

Under the plan, officials will carry out a method known as addling, which prevents eggs from hatching. The technique will mainly target eggs laid by feral Greylag Goose.

Authorities say the island’s feral geese have no natural predators and their numbers have steadily increased in recent years. Estimates suggest the population had grown to around 300 birds by 2025.

According to officials, a range of groups – including environmental organisations, farmers, landowners and local businesses – have raised concerns about the growing flock and its impact on the area.

Addling involves coating eggs with liquid paraffin oil, which blocks oxygen from entering through the shell and stops the embryo from developing.

Once treated, the eggs are returned to the nest so the female goose continues incubating them. This approach is designed to prevent the bird from abandoning the nest and laying another clutch elsewhere.