The first results of a new, live-animal test for chronic wasting disease found that 13 of 117 captured elk in Rocky Mountain National Park were positive.

The results mark the initial fruits of an unprecedented research and population-control project in the park. It was designed, in part, to evaluate the use of a live test for the fatal disease on wild, free-ranging elk. A live test has been in use for deer.

The rate of infection – 11 percent – appears high for elk. Typical disease rates in the wild have hovered closer to 1 percent or 2 percent.

A National Park Service statement said researchers weren’t surprised, however, because the park’s herd is larger, less migratory and more concentrated than it would be under natural conditions, with hunting and predators to scatter the animals. Such confined conditions make the spread of CWD more likely.

“Research has also shown that elk densities on the core winter range (in the park) are the highest concentrations ever documented for a free-ranging population in the Rocky Mountains,” the park service said.

A total of 136 elk were captured from January through mid-March from herds in Moraine Park and Beaver Meadows on the park’s east side. Of those, 117 yielded usable tissue for CWD testing. At the time of capture, none of the animals exhibited symptoms of the illness.

The CWD testing is part of a broader effort, also designed to reduce elk numbers in the park and test a new birth-control drug for the animals.

The elk population, unchecked by hunters and wolves, has grown too large for the park to support, ecologists say, leading to overgrazing on willows and aspen, and damaging habitat for other plants and animals.

Elk testing positive for CWD will be among up to 200 a year killed in the park as part of the effort to reduce population to a target herd size of 1,600 to 2,100. Just how many elk are culled per year will depend on annual population surveys and hunter success.