Deer with Collars

Recently many visitors are asking why so many deer in Rocky Mountain National Park have collars. This question will be asked even more frequently in the next few years as park staff attempt to collar every deer in the park. But we aren't just doing this out of curiosity, we are trying to combat a serious animal heath threat - Chronic Wasting Disease or CWD. CWD is thought to be an exotic disease of deer and elk caused by improperly folded proteins called prions. It is invariably fatal. Models suggest that if five percent of the deer in a population are affected, the population is likely to die out. Unfortunately, recent studies have shown deer populations in the park have about a five per cent infection rate and are thus at risk.

Rocky Mountain National Park is working in close cooperation with the Colorado Division of Wildlife to test an experimental management approach for CWD that may prove effective in a limited number of situations. This approach involves capturing every deer over a year old, taking out part of the deer's tonsils for lab testing, and collaring it so that it may be located in the future if it is found to have CWD. If an animal is found to be infected, it will be euthanized. There is no cure. While this method is very labor intensive, the park hopes this project will be an effective way to control CWD and protect the future of our deer herds. Unfortunately there is no live test for elk, so such an approach is not possible for them. If you see a collared elk, it is part of another research or management project.

If you see a deer with a collar on your next visit to Rocky Mountain National Park, know we are trying to make sure these lovely animals will live healthy lives and be here for future generations to enjoy.

Last updated: March 31, 2012

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1000 US Hwy 36
Estes Park, CO 80517


970 586-1206
The Information Office is open year-round: 8:00 a.m. - 4:00 p.m. daily in summer; 8:00 a.m. - 4:00 p.m. Mondays - Fridays and 8:00 a.m. - 12:00 p.m. Saturdays - Sundays in winter. Recorded Trail Ridge Road status: (970) 586-1222.

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