Necropsy and mortality narrative for gray wolf capture mortality completed

Luke Perkins
Statewide Public Information Officer
303-392-5789 / l[email protected]

February 27, 2026

DENVER – A CPW-conducted necropsy has confirmed that gray wolf 2305 died from capture-related complications during collaring operations on public lands on January 28, 2026. These complications led to acute cardiogenic shock which could have been exacerbated by several different factors including hyperthermia, exertional/capture myopathy, respiratory distress or drug reaction.

An independent third-party veterinary pathologist was in attendance for the necropsy and confirmed all exam results.

"As we said shortly after this mortality occurred, all wildlife capture operations come with a risk and while we meticulously prepare and take every precaution to ensure a positive outcome, there is always the possibility, even if small, that the worst happens,” said CPW Director Laura Clellan. “Our staff and contractors carefully followed CPW Animal Care and Use Committee (ACUC) guidelines during this operation, and by all accounts the capture process was not abnormal nor suggestive of this level of stress response from the animal.”

As outlined in the mortality narrative, locating, pursuing, capturing, securing, and transportation of gray wolf 2305 to CPW’s handling crew occurred concurrently with the capture of the breeding female in the King Mountain Pack (and after a pup was captured). These aspects of the operation lasted approximately 24 minutes, with the pursuit time of 2305 being approximately 3 minutes.

During the capture, 2305 was not panting in any abnormal way (i.e., no obvious signs of distress were observed) and the entire process was noted as short and benign by the capture crew. 2305 was darted in the muscle in the upper left hind leg, an appropriate location to place a dart.

When delivered to CPW’s handling crew at the processing location, as standard practice, temperatures were taken of both adult wolves. 2305 was noted to be very hot compared to the breeding female (105.8 degrees F versus 101.4 degrees F).

CPW staff immediately initiated measures to attempt to lower the body temperature for 2305. The temperature of the breeding female was not of concern.

While 2305’s temperature was being taken and cooling measures were initiated, 2305 was checked for respirations and a pulse, of which neither were detected.

CPW’s handling crew immediately began to attempt to revive the animal.

Approximately 20 minutes after 2305 was delivered to CPW’s initial handling crew, a secondary crew including CPW’s wildlife veterinarian arrived and she confirmed respiratory and cardiac arrest. In addition to attempts to revive 2305 prior to the arrival of the secondary crew, CPW’s wildlife veterinarian then administered emergency drugs intended to increase heart rate while CPR was performed. When no pulse or respirations — as well as a lack of corneal and pupillary reflex — were confirmed, CPR was ceased and the animal pronounced dead.

The animal was delivered to CPW’s Wildlife Health Laboratory on the evening of Jan. 28 and the necropsy was conducted on the afternoon of Jan. 29. CPW received permission to conduct the necropsy (instead of at a federal facility) from the U.S. Fish and Wildlife Service to help expedite the process.

"The female and male wolves were in close proximity to each other during the capture operation,” said Clellan. “Our staff have combed through every detail to try to determine why the male wolf died while the female wolf had no issues. The evidence and facts within the reports still don’t definitively point to a specific reason why the male wolf experienced such a high level of distress. We have a top notch professional team, and this situation has been tough on everyone involved. I have the utmost confidence in our staff and we will continue to work hard to achieve our mandate of restoring a sustainable population of gray wolves in Colorado.”

In addition to the capture of 2305, the breeding female and a pup in the King Mountain pack were successfully captured and collared during this operation. Monitoring indicates that these two are still traveling together.

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