Deer Mouse Behavior Links Disease Transmission With Biodiversity
For his first movie about a mouse, Walt Disney showcased Mickey navigating the river waters by steamboat. But for Dr. Laurie Dizney, the filming of mice happened in the dry Utah desert. Her work shows how using mice and cameras could help protect people from hantavirus and other deadly diseases.
New research published by University of Utah scientists in this month’s issue of the journal Animal Behaviour suggests that more diverse ecosystems have a lower prevalence of zoonotic diseases, which can be transmitted from animals to humans. Many zoonotic diseases come from rodents, including Lyme disease, which is transmitted from rodents to humans by ticks, and hantaviruses, which humans can breathe in if they are in an area with lots of rodent urine or droppings.
“And so, with hantaviruses, or at least Sin Nombre virus, the virus is spread between deer mice, who are the hosts, through aggressive behavior. And so we thought behavior would be a good place to start looking at that, if somehow biodiversity affected behaviors of organisms within the ecosystem.”
Dr. Laurie Dizney, a former post-doctoral researcher at the University of Utah who is now a lecturer at the University of Portland, and her colleague Dr. Denise Dearing, trapped deer mice at two locations in Juab County, one where only deer mice and pocket mice are found and the other where the rodent community also includes western harvest mice, pinyon mice, and kangaroo rats. They devised a sneaky way to spy on the mice that they marked without interfering with their normal behavior.
“The surveillance system we had was really kind of cool, I thought. It integrated both infrared technology with the cameras as well as PIT tag technology.”
PIT tags are similar to microchips that your cat or dog might get, and a microchip reader at each of several feeding stations told the researchers which mouse was which. Dr. Dizney’s cameras, which were trained on the PIT tag readers, video-taped the deer mice on the less diverse site engaging in five times as many aggressive interactions.
Dizney and Dearing reasoned that bolder mice do better in areas with lower biodiversity, but apparently a population of mostly bold mice is a recipe for spreading hantavirus. Hantavirus prevalence was four times higher at the less diverse site. So, Dizney’s work suggests that competitors like kangaroo rats, and predators, such as owls and rattlesnakes, might indirectly reduce the prevalence of hantavirus and the likelihood that it will spread to nearby humans.