Hunters, hikers, ticks, and deer: Can deer management help mitigate Lyme disease?

We explore the potential role of deer hunting for mitigating the risks of Lyme disease, which affects nearly a half million people in the U.S. every year. Lyme disease is a zoonotic disease spread to humans by black-legged ticks, and white-footed mice and white-tailed deer are among the primary hosts for black-legged ticks. Mice can infect ticks with the Lyme bacterium (Borrelia burgdorferi), but deer cannot. Therefore, deer may either harm or benefit hikers by amplifying or diluting Lyme risks. We developed a bioeconomic model to study the potential benefits of managing deer hunting for controlling Lyme disease. Our model includes linkages between the three main life stages of ticks, three distinct groups of tick hosts, and the recreation behaviors of hunters and hikers. We used the model to identify conditions under which deer can amplify or dilute Lyme risk, and we conducted a variety of sensitivity analyses to compare the optimal hunting fee, deer harvest, Lyme risk, and hunters’ and hikers’ welfare when a manager maximizes either hunting yield, hunter welfare, or combined hunter and hiker welfare. Our analysis provides new insights about ecosystem-based management when wildlife species may provide both positive and negative services.