Even the thought of them can make people’s skin crawl.
But for Dr. Elizabeth Gleim, assistant visiting professor at Oxford College, the blood-sucking arachnids are fascinating.
“I enjoy ticks,” she said. “They don’t weird me out. I get excited when I see them. I definitely have a healthy appreciation for them [because] they do carry pathogens, so I definitely check myself carefully after I’ve been doing field work in the forest.”
Increased tick populations have led to an upswing in the spread of tick-borne diseases such as ehrlichiosis, southern tick associated rash illness (STARI), Rocky Mountain spotted fever, and the well-known though not as common in Georgia Lyme’s disease.
“The more we encroach on ideal wildlife habitat, the more we encounter tick populations,” she said.
So how can tick populations be controlled?
Turns out, what’s good for the forest is good for controlling ticks—prescribed burns.
A land management technique that’s been used by forestry services at the state and local level, as well as by private land owners, a prescribed burn is the controlled application of fire by a team of experts that restores the health of a forest. It burns off excessive brush, shrubs and trees and encourages the growth of some native vegetation. It can also help lessen the damage caused by a wildfire.
It also, Gleim says, decimates tick populations.
A biologist specializing in wildlife disease ecology, Gleim has spent four years studying the impact of prescribed burns of pine and mixed pine forests on exploding tick populations. Two and a half years of that research was spent visiting pine forests in southern Georgia and northern Florida, collecting over 47,000 ticks at 21 different sites.
“Basically, we were wanted to look at the effects of prescribed burns on tick populations and the implications for human public health,” Gleim said. Because of human encroachment on rural lands, “there’s been a big push to try and understand how human land use might be effecting tick populations and to find ways to potentially reduce those tick populations.”
Gleim said that at the unburned site, she encountered 60 ticks per hour. At burned sites, that number was reduced to 0 to 2 ticks an hour. Of that number, .7 ticks tested positive for pathogens that could infect humans in the unburned areas. That number dropped to .2 infected ticks per hour.
The prescribed burn “really decreased encounters with infected ticks,” she said.
It also had an impact on properties adjacent to the burned area, she said. “It seems like it’s not only benefiting the area burned, it’s effecting the area around the prescribed burned land,” she said. “That was something we weren’t expecting.”
Up until the study was complete, there had been conflicting data about prescribed fires and tick populations, she said. But as with land management practices, it’s the long-term, repeated use of prescribed burns that is key to controlling tick populations.
“As long as prescribed fire is used on a regular basis you will over time to see reduction in tick populations,” she said. “[The burn is] definitely a good thing for the forests and also for people and animals.”
On state and federally owned lands, prescribed burns are usually done by the departments of natural resources. They are, she said, huge champions of prescribed burning “as far as benefitting wildlife and plants. Not only is it good for the eco-system, it’s good for human health.
“This is a promising way to reduce and control tick populations,” she said.
Private owners, however, must make arrangements for prescribed burns, and they aren’t necessarily right for every piece of land, she said. “If you have a hardwood forest or a small piece of land, burning might not be the right thing. If you have a mixed pine forest or you own a piece of property that’s several acres, I would definitely consider prescribed burning.”
The best thing a private land owner can do is contact the Georgia Forestry Commission about whether or not a prescribed burn would benefit their land.
Now that this stage of the research is completed, Gleim said they will model long term impact prescribed burns will have on tick populations. “Once we have the model in place, we’ll go out in the real world and find property that hasn’t been burned, and burn it.”
Gleim’s research has been published online at PLOS One in an article co-authored with Mike Conner of the Joseph W. Jones Ecological Research Center, Michael Levin and Galina Zemtsova of the CDC, and Michael Yabsley of Warnell and Southeastern Cooperative Wildlife Disease Study at the University of Georgia. The study is available online [http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0112174].
The study was funded by a collaborative grant through the University of Georgia and the Center for Diseases Control and Prevention, with additional funds provided by the Joseph W. Jones Ecological Research Center at Ichauway, the Warnell School of Forestry and Natural Resources and the Southeastern Cooperative Wildlife Disease Study in the UGA College of Veterinary Medicine.