An outbreak of toxic bacteria in California’s newly reformed Lake Tulare is killing birds stopping off at the lake on their migrations. Two dead birds collected from the lake—a mallard duck and a white-faced ibis—have tested positive for avian botulism caused by toxin type C, the California Department of Fish and Wildlife (CDFW) said in a statement Tuesday. It comes as Lake Tulare, a previously dried-up lake in the San Joaquin Valley, grew nearly as large as Lake Tahoe due to an influx of meltwater from this winter’s record-breaking snowpack in the Sierra Nevada mountains.