Are too many wolves dying in Colorado? CPW: Mortality rate "not surprising"

Colorado’s wolf reintroduction program is facing scrutiny as mortality rates among the relocated animals raise questions about the project’s long-term viability. While officials caution against drawing premature conclusions from the early data, the recent death of an 11th wolf has brought the total number of confirmed wolf deaths to 12 since the program began.

Understanding the Numbers

As of this week, 19 collared wolves remain in Colorado, following the initial relocation of 25. This figure does not include any uncollared wolves that may have migrated into the state, nor does it account for pups born to four litters this spring. The Colorado Parks and Wildlife (CPW) emphasizes the small sample size and short timeframe when assessing the program’s success.

A History of Reintroduction Challenges

CPW spokesperson Luke Perkins explained that the agency’s Wolf Restoration and Management Plan initially cited a 70% survival rate as a benchmark. However, this figure applies only to the first six months after translocation. The 70% threshold was initially conceived as a trigger for a protocol review, modeled after challenges encountered during the reintroduction of Canada lynx in the late 1990s.

Did You Know? Colorado initially attempted a “hard release” of lynx – directly releasing them into the wild – which resulted in high starvation rates before CPW shifted to a pen-and-feeding approach.

The lynx program was ultimately deemed successful by 2010 after adjustments were made to improve the animals’ chances of survival. Currently, the survival rate for reintroduced wolves stands at 56%.

Causes of Wolf Mortality

CPW investigations indicate that the deaths are not attributable to the capture, transport, or release protocols. The identified causes of death include conflict with other wolves, encounters with mountain lions, trauma from a snare, being struck by a vehicle, and, in one case, lethal removal by CPW. Three deaths remain under investigation by the U.S. Fish and Wildlife Service.

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).

Expert Insight: The observed mortality rate, while concerning, is not necessarily unexpected given the challenges faced by dispersing wolves in the broader western North American landscape.

CPW notes that wolf life expectancy in the Rocky Mountains, outside of protected areas, can be as low as 2.5 years, with an annual survival rate of 75% or less. Dispersing wolves, those not living in established packs, face even higher risks.

Looking Ahead

CPW has announced that there will be no further wolf capture operations in 2026, following a directive from the U.S. Fish and Wildlife Service to halt imports from Canada. Eric Odell, CPW’s wolf program manager, stated that the impact of foregoing a third year of translocations is uncertain. However, he cautioned that continued high mortality rates could jeopardize the establishment of a self-sustaining wolf population in Colorado, potentially requiring additional resources.

Frequently Asked Questions

What is a “hard release”?

A “hard release” refers to the type of capture and the amount of time an animal spends in captivity before being released into the wild.

What survival rate did the Colorado Wolf Restoration and Management Plan initially target?

The plan initially cited a 70% survival rate as a threshold for success, but this figure applied only to the first six months after wolves were translocated.

How many wolf deaths are currently under investigation?

Three wolf mortalities (collar numbers 2309, 2506, and 2504) are currently under investigation by the U.S. Fish and Wildlife Service.

Given the complexities of reintroducing a predator species, what factors do you believe will be most critical to the long-term success of Colorado’s wolf program?

Are too many wolves dying in Colorado? CPW: Mortality rate “not surprising”