Researchers track mice movements

By Lana Groves, Asst. News Editor

Hikers and campers traveling through the wilderness might be able to better avoid the painful and often deadly hantavirus thanks to a new U study. By tracking the movements of mice in a natural habitat in southern Utah, U researchers found that bigger, older mice were more likely to come into contact with other mice to potentially spread disease.

Christy Clay, a former U doctoral student, worked with biology professor Denise Dearing on a study to find out if male deer mice spread the virus more often because they fight or because they come into contact with other mice while defending their territory. Dearing said other researchers could document land throughout Utah where there is a higher risk of contracting the virus and view warnings near a trail or on the Internet.

Clay and Dearing used five colors of fluorescent talcum powder on different mice and showed that older mice were more likely to have powder on them after just two nights.

“When you’re older, you have more experience and are likely to have established your territory,” Clay said. “They might need a bigger foraging range or maybe there’s a hierarchy that comes with age in mice. Could be all of those factors.”

Dearing said researchers hypothesize that mice spread the disease by airborne particles and through saliva from biting. Humans who contract it often die or suffer from painful damage to the lungs and spleen. About 500 people have been diagnosed with the virus since it was recognized in the early 1990s.

Researchers checked their results by using a second tracking method at their site in the Tintic Mountains, implanting a device similar to the tracking mechanism pet owners use to find lost cats or dogs.

Both methods show that most mice came in contact with only one or two other mice within two nights8212;enough to spread a disease.

Researchers also documented some of the habitats that older, bigger mice frequented the most, which could help people avoid high risk areas.

Dearing said mice prefer staying in areas that have large amounts of sagebrush coverage. Other researchers could document land throughout Utah where there is a higher risk to contract the virus and view warnings near a trail or on the Internet.

Clay finished the study in 2006, but another graduate student working in Dearing’s lab is continuing to look at how mice spread the virus. The researchers are using a video surveillance system to monitor the behavior of mice. The second study is showing that younger mice tend to avoid conflict.

“It looks to us as if that second mouse knows there’s a mouse already there and seems to be making a calculated decision not to challenge that other mouse,” Dearing said. “Just think, how often do you go into a restaurant and beat someone up over it?”

The study was published online Jan. 7 in the British journal Proceedings of the Royal Society B.

Dearing said the study helps researchers better understand mice behavior and how the virus is spread, but they still want to look into why male mice tend to spread the virus more often.

She said it could be a genetic factor or another reason, but only further studies will tell.

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