A dangerous bird flu, in other words, was suddenly circulating in mammals—mammals with which people have ongoing, extensive contact. “Holy cow,” says Thomas Friedrich, a virologist at the University of Wisconsin–Madison. “This is how pandemics start.”

A warning has been issued after a confirmed case of bird flu was found in a wild herring gull. Devizes Town Council has urged dog owners to take care after the bird was found dead in the town with H5N1 Avian Influenza as part of ongoing surveillance work.