A bird flu surveillance zone remains in place over a large section of the Somerset Levels following an update from central government.

Highly pathogenic avian influenza (HPAI) H5N1 was first detected on a "large commercial poultry premise" near Ashcott (between Bridgwater and Street) on November 29, 2025.

Following this detection, the Department for the Environment, Food and Rural Affairs (Defra) instituted a three-mile protection zone around the offending premises and a ten-mile surveillance zone – with all poultry at the affected site being culled.

Following "recent changes to bird gatherings", Defra has slightly changed the boundary of both the protection and surveillance zone, with signs being put out on main roads to alert motorists passing through.

This comes as a three-kilometre (1.8-mile) "captive bird controlled zone" was put in place in the Dunwear area of Bridgwater following a separate outbreak of the same strain among "non-commercial captive birds".

The three-mile protection zone includes the villages of Ashcott and Walton, along with a small section of Street (including the Street Business Park on Gravenchon Way) and a substantial part of the Avalon Marshes local nature reserve.

The ten-mile surveillance zone now extends over the entirety of Butleigh, Compton Dundon, Glastonbury, Middlezoy, Othery and Street, along with most of Somerton and Westonzoyland, the eastern edge of Woolavington and the southern edge of Wedmore.

Any business involving poultry within either the protection zone or the surveillance zone must keep assiduous records of all visitors, including dates, times, and whether any individuals interacted with the birds on the premises.

'Mandatory housing' measures also remain in place, with advice being issued by the Animal and Plant Health Agency (APHA).

A spokesperson said: "If you have 50 or more birds, you must house them. This applies to all types of birds.

"If you keep less than 50 birds and they are for your own use only (e.g. you do not sell or give away their eggs or meat), you do not have to house them.

"If you keep less than 50 birds but you do sell or give away their eggs, poultry products or live birds, you must house them."

Defra and the APHA have jointly confirmed that these restrictions will remain in place until further notice – with any updates being published on the official Defra website.