Avian botulism is taking toll on birds

Thousands of dead birds are showing up along the shore of the Great Salt Lake.

The Utah Division of Wildlife Resources estimates that 20,000 to 50,000 birds have died so far this year from avian botulism, a toxin that periodically plagues birds at the lake.

Biologists say the outbreak ramped up in early August and is expected to last into the fall. State wildlife disease expert Leslie McFarlane says this year's outbreak is considered moderate. A similar episode in 1997 killed about a half-million birds around the lake.

The botulism bacterium is commonly spread when birds eat maggots from a dead bird that's been infected.

McFarlane says people shouldn't allow their dogs to pick up dead birds found along the lake's shoreline.

— Associated Press