MATHER — Wildlife officials confirmed that the swans found dead at Mather Regional Park in Sacramento County in November were infected with bird flu. This latest announcement comes after a month of people wondering what killed these swans. Since the original grouping of swans was tested, more have died.

There have been smaller suspected HPAI outbreaks at other undisclosed Massachusetts locations in recent weeks, which officials said affected less than 15 geese at each site.