Eleven feral burros found dead in Death Valley National Park

A group of eleven feral burros were recently found dead in Death Valley National Park. Park officials suspect toxic algae was to blame.

Burros are a type of wild donkey adapted to deserts, and the population of about 4,000 descend from ones released decades ago by miners. The dead burros were found near Owls Hole Spring, which DVNP officials have warned is not unsafe for contact or drinking from by animals or people, officials said in a release Wednesday. 

While the exact cause of the donkey’s demise is being investigated, the going hypothesis is that a a bloom of toxic algae was to blame. Algae can bloom when water is slow-moving or still, when temperatures are high and when nitrogen and phosphorus is introduced via sewage or fertilizer.

Owls Hole Spring fit all three criteria. Its water is stagnant, the burros had defecated near and into the spring and Death Valley experienced its hottest year on record in 2024, park officials said.

While rangers have thus far only found dead burros, other animals were also likely to have been affected.

“I hate to see any animal suffer. The National Park Service is working to remove feral burros from Death Valley,” DVNP Superintendent Mike Reynolds said.

Large-scale burro roundups have not happened in DVNP since 2005 due to a lack of funds, but are slated to resume in fiscal year 2026.