Editor’s note: This story has been updated to correct the date of the most recent wolf death.

One of Colorado’s reintroduced wolves died on Thursday, May 15, in the state’s northwest region. 

Parks and Wildlife officials confirmed Friday that they received a mortality alert on the female wolf’s collar on Thursday. The agency provided no additional details on the incident or the cause of death. 

The U.S. Fish and Wildlife Service will conduct the investigation and necropsy to determine what caused its death.  

The wolf’s death marks the fourth death this year of the 15 animals that Colorado Parks and Wildlife brought from British Columbia in January. 

A male wolf was killed in March by the U.S. Department of Agriculture’s Wildlife Services after being connected to the death of five sheep in north-central Wyoming. A few weeks later, in April, a second male wolf was killed in Wyoming, where wolves can be killed at any time without a license in the majority of the state. Then, on April 25, a female wolf died in Rocky Mountain National Park. This death is also still under investigation by the Fish and Wildlife Service.   

Since reintroduction began in December 2023, seven wolves have died, two others to natural events, including mountain lion and wolf attacks, as well as one that was illegally shot. 

Last week, Eric Odell, Parks and Wildlife’s wolf conservation program manager, commented that the mortalities so far were not cause for concern.

“These mortalities are unfortunate in our sense of trying to establish a self-sustaining population of wolves, but it does not in any way indicate a failure of the program,” he said.