Utrecht – There are concerns about black-headed gulls. The birds have been found dead more and more often since the end of January and bird flu has been detected in at least five gulls in the Netherlands, the Dutch Wildlife and Health Center (DWHC) reports together with Sovon Bird Research. Dead birds from Utrecht are also currently being examined for bird flu. It is feared that, with the breeding season approaching, more and more gulls will carry and transmit bird flu, causing an outbreak.