Colorado Parks and Wildlife is cautioning the public against misinterpreting the number of wolf deaths since the state’s reintroduction program began, “especially over such a short time period and with such a small sample size,” the agency said.
This comes after an 11th gray wolf of the initial 25 brought to Colorado died, bringing the total number of collared wolves in the state to 19, following the May killing of one wolf born to the Copper Creek pack and the deaths of two that were in the state prior to relocation starting. The current tally of wolves in Colorado does not include any uncollared wolves that might have wandered into the state, CPW said, nor pups from four litters that have been born since spring, which have not yet been counted.
Luke Perkins, CPW spokesperson, said information in the Colorado Wolf Restoration and Management Plan regarding survival rates can be confusing – particularly language citing a 70% survival rate as threshold for success.
Some people are missing that the 70% figure applied “only to the first six months after wolves are translocated,” Perkins said.
The plan also states that if the survival rate does go below 70% after the first six months, it would “initiate a protocol review.” But that language “was intended to address circumstances similar to what we observed when Canada lynx were reintroduced,” Perkins said, and to ensure that wolves are responding well to hard releases.
A “hard release” refers to the type of capture and amount of time an animal spends in captivity.
Colorado’s initial hard release of lynx in the late 1990s failed due to high starvation rates, before CPW changed course and moved the cats into a pen, fed them and trained them to hunt. By 2003, the lynx had successfully reproduced, and by 2010 the project was deemed a success.
With the 11th wolf’s death last week, the survival rate of reintroduced wolves is 56%.
“But by looking back at wolf mortalities, we can see … that no wolf mortalities are a direct result of capture, transport or release protocols and only one is a result of management action by CPW,” Perkins said.
- One wolf died as a result of conflict with another wolf (collar number 2303).
- Two died as a result of conflict with mountain lions (2307 and 2514).
- Three died in Wyoming (2505, 2513 and 2304).
- One died due to secondary trauma from entrapment by a lawfully set snare (2512).
- One from blunt force trauma from being hit by a vehicle (2507).
- One was lethally removed by CPW and its agents (2405).
- And three mortalities are still under investigation by the U.S. Fish and Wildlife Service (2309, 2506, and 2504).
Those equal 11 relocated wolves and one born in Colorado. CPW also evaluated the capture, transport and release protocols used for wolf reintroduction and found that there is no need to modify any of them since none of the deaths were attributable to the reintroduction protocols.
And while mortality among reintroduced wolves has seemed high, it has not been unexpectedly high, said Perkins.
Across western North America, wolf life expectancy is much lower than many anticipate. Though variable in the Rocky Mountains outside of highly protected areas (like large national parks), the adult survival rate can be 75% per year or lower with an expected lifespan of 2 1/2 years. And when wolves do not live in a pack (i.e., while dispersing), some research shows that they are at an even higher risk of death, and survival per year can be closer to 67%.
So “since the translocated wolves are essentially ‘dispersers,’ we can see that the amount of mortality we are observing in Colorado is not surprising,” Perkins said. “And with the current small wolf population, each mortality event has a large effect on overall survival rates.”
But now some people are hoping there are no more mortalities, because CPW on Wednesday announced there will be no capture operations in 2026.
The announcement follows an October directive from the U.S. Fish and Wildlife Service ordering Colorado to stop importing wolves from Canada, which stalled the state’s plan to relocate 10 to 15 wolves from British Columbia.
“It is not possible to predict the impact of foregoing a third year of translocations without knowing what may occur in the coming year,” Eric Odell, CPW’s wolf program manager, said in a statement.
But ‘if mortality remains high, as observed in 2025, the risk of failing to achieve a self-sustaining wolf population in Colorado increases, potentially requiring additional resources to address,” Odell said.