Image of the Day: Low Water Flow Triggers Avian Cholera

Northern pintail ducks flock to the wetlands of the Lower Klamath National Wildlife Refuge during their migrations in Oregon, as seen in this photo. More than 10,000 migrating birds in the U.S. have died from an outbreak of avian cholera caused by reduced water flowing through marshlands of Oregon and California, according to federal wildlife officials. The marshland area is fed mainly by runoff from melting snow in the Cascade mountain range.The drier conditions force the birds to gather in smaller areas and those crowded conditions help spread the disease. Avian cholera appears in the region nearly every year, but the current bird die-off there is the worst in over a decade, said Matt Baun, a spokesman for the U.S. Fish and Wildlife Service.

Credit: UFWS/Reuters