Oregon Live At least 5,000 birds have died so far this summer at a network of wildlife refuges on the Oregon-California border, sparking fears of another large outbreak of disease and calls for more water releases in a region roiled by drought and water uncertainty made worse by climate change.
The deaths are likely caused by a rare combination of avian flu and botulism, said John Vradenburg, supervisory biologist at the refuge complex. Virus-caused avian was confirmed at one of the refuges in July, Vradenburg said. Avian flu has been on the rise in recent years, leading to die-offs in poultry and wild birds.