A new outbreak of bird diseases has killed more than 5,600 birds at southern California's Salton Sea in the past month, the U.S. Fish and Wildlife Service announced today. The U.S. Geological Survey's National Wildlife Health Center in Madison, Wisconsin, has diagnosed avian cholera, a bacterial infection, as the killer of more than 1,800 ducks and geese.
Ruddy ducks are the hardest hit species.
Waterfowl are especially vulnerable to the rapid spread of this disease where they concentrate in large numbers. In a second current disease outbreak, over 2,400 eared grebes have died from an unidentified disease that may be a recurrence of a similar outbreak that killed 150,000 grebes in 1992. The cause of the grebe mortality remains unknown. The current disease outbreak has killed birds of 51 species. Regular die-offs of tilapia, an introduced African fish and the most common fish present in the Salton Sea, also have occurred throughout January.