11 feral donkeys also known as burros were found dead in Death Valley National Park and park officials have issued a warning to the public about a toxic algae bloom that likely killed the animals.
Death Valley’s estimated population of 4,000 wild burros are not native to the land. They were released by miners in the 1800s and have since flourished in the barren landscapes. The invasive burros are originally descended from the African wild ass. According to Death Valley, the invasive burro populations grow at approximately 20% per year and are detrimental to to native vegetation, spring ecosystems and compete for limited resources with native wildlife, such as bighorn sheep and desert tortoise.
The 11 burros that recently died were discovered near Owls Hole Spring. The cause of the deaths is currently under investigation. The likely culprit is algae bloom in that hot stagnant water present in Owls Hole Springs. Park officials warn that water in Owls Hole Spring should be considered unsafe for humans or pets to drink or touch.
Currently only dead burros have been found but park officials believe other animals were likely affected.
Death Valley National Park New Release:
Eleven burros died in near Owls Hole Spring in Death Valley National Park. The cause of death is under investigation, but the National Park Service (NPS) suspects a harmful algae bloom was to blame.
The NPS warns that the water in Owls Hole Spring should be considered unsafe for humans or pets to drink or touch. In addition, people and pets should not handle any of the carcasses. Park rangers installed a warning sign.
Algae and cyanobacterial occur naturally in water and are more likely to grow into a harmful algae bloom when water is slow-moving, warm, and contains high levels of nitrogen and phosphorous, such as from fertilizer or sewage, according to the Centers for Disease Control (CDC).
All three of those conditions existed at Owls Hole Spring this summer where the water is stagnant. Death Valley experienced its hottest summer on record this year and feral burros defecated in and near the water.
So far only dead burros have been found, but other animals were likely affected. No pupfish live in this spring.
“I hate to see any animal suffer. The National Park Service is working to remove feral burros from Death Valley, for their own safety and to reduce impacts to native wildlife.” –Superintendent Mike Reynolds
Burros are not native to Death Valley. The park’s estimated 4,000 burros are descendants of animals released by miners decades ago. The NPS seeks to relocate feral burros from the park. Due to lack of funding, roundups have not been conducted on a large scale since 2005. The Bureau of Land Management worked with the NPS to remove 43 burros in recent years. The nonprofit Peaceful Valley Donkey Rescue has captured 256 burros from the park since 2018. The park has funding to resume roundups in fiscal year 2026.