A red-breasted goose that died at Jersey Zoo last month has since tested positive for bird flu.
It's the third case of the virus to be found in the island, after two dead buzzards tested positive last month.
Chief Vet Alistair Breed is urging Jersey birdkeepers to house their flocks.
"Upon testing, the bird from the zoo was found to be positive for highly pathogenic Avian Influenza. Following on from this, we will shortly be introducing compulsory biosecurity measures relating to poultry and kept birds on the whole Island.
Private bird keepers should do everything possible at this time to ensure their flocks avoid contact with wild birds. We are working closely with the zoo on control measures there to help protect their collection."
There have been several outbreaks across France and the UK in recent months, including in the East Anglia region earlier this week.
The Director of Operations at Jersey Zoo, Graeme Dick, says their priority is to stop the virus from spreading further by following all guidance issued by Mr. Breed.
"Our experienced team are well prepared to deal with scenarios like this and will do everything they can to keep our birds safe.
We have closed our walk-through aviaries, but I would like to reassure our visitors that it is still safe to visit the zoo and we are monitoring the situation closely."
The UK Health Security Agency says the risk to public health is low.
People are advised not to handle unwell or dead wild birds.