WILLARD, Utah (ABC4) — Thousands of birds were found dead in the Willard Spur and Harold Crane Waterfowl Management areas of the Great Salt Lake near Willard and experts believe an outbreak is to blame.

Biologists with the Utah Division of Wildlife Resources first discovered dead and sick birds in mid-September. Video from DWR taken from a boat sailing on the waters of Willard Bay shows hundreds of dead birds in the water.

Bodies of birds killed by an avian botulism outbreak seen in the Great Salt Lake.
Bodies of birds killed by an avian botulism outbreak seen in the Great Salt Lake. (Courtesy of Utah Division of Wildlife Resources)

Many of the found birds were collected and submitted for disease testing. Biologists said those tests came back negative for the avian flu, which has reportedly been on a decrease in Utah. While the final results of the tests are still pending, biologists are beginning to suspect the birds have died of avian botulism.

“Avian botulism is a paralytic, often fatal, disease of birds that results from the ingestion of a toxin produced by a bacteria, Clostridium Botulinum,” explained DWR spokesperson Faith Jolley. “The toxin is produced under certain environmental conditions in the summer and fall when there are low oxygen levels and warm water temperatures.”

According to the United States Geological Survey, botulism can cause paralysis and eventually death in birds. Waterfowl, gulls and shorebirds are most often affected by botulism. Birds affected have a hard time holding up their heads or show difficulty taking off for flight. Sick and dead birds end up most often being found along the shoreline.

Jolley said botulism mainly appears in stagnant pools where there is no water flowing and typically between July and September. However, this year, a particularly large number birds were infected by avian botulism. While DWR doesn’t have an exact confirmation of how many birds have been impacted, they estimate the number is in the tens of thousands.

“Our wetland managers strive to make adjustments in their water management practices on state waterfowl management areas in order to keep fresh water flowing, which can help minimize the impacts of avian botulism,” said DWR Waterfowl Coordinator Jason Jones. “Many of the waterfowl management areas were originally created to reduce the botulism outbreaks that occurred along the river deltas a century ago.”

While the risk of transmission of avian botulism between birds and humans is low, DWR said it’s still important to take safety precautions if you encounter sick or dead birds, especially for waterfowl hunters:

  • Harvest waterfowl that are actively flying.
  • Avoid harvesting or consuming birds that appear sick or weak.
  • Cook meat thoroughly, as heat will denature the toxin.
  • Botulism can affect dogs if they consume the meat, so keep dogs away from sick, dead or dying birds.

DWR said you should not handle or touch a sick bird, should you encounter one. Also avoid feeding the birds, as the incorrect food could actually cause more harm to the bird.

Jolley said the best thing to do is to keep a safe distance away from the bird which will help avoid stressing the bird out further.