MD Islander speaks with Gardner about link between ticks, Acadia fire of ’47

Mount Desert Islander spoke with Allison Gardner, an assistant professor of arthropod vector biology at the University of Maine, about a study she’s leading that found ticks are more abundant in parts of Acadia National Park that burned in the October 1947 fire. “We’re trying to establish associations between where we see high densities of ticks and various environmental variables,” said Gardner. “We’re conducting this research because we want to be able to inform visitors about where they are most likely to get exposed to ticks in the park, which can potentially help them protect themselves.” Gardner said her research team also has been collaborating with National Park Service staff to inform landscape management strategies with the goal of protecting visitors against ticks. And she is not surprised by the discovery of more ticks in the previously burned areas. “We think the reason we’re seeing that pattern is that, since the fire, most of the vegetation in that area of the park is deciduous, and ticks generally seem to be more commonly found in hardwood forests than in softwood forests,” Gardner said, because mice and deer, the ticks’ primary host animals, are found more in those forests. Another factor could be that ticks are sensitive to humidity, and hardwood forests tend to have a thicker layer of leaf litter that ticks can use as shelter to prevent themselves from drying out, according to Gardner. “It’s really fascinating seeing that this disturbance that occurred more than 70 years ago is still having impacts that have potential implications for human health,” she told Mount Desert Islander. Sarah McBride, a UMaine graduate student, and a group of undergraduate students are in Acadia for the second summer in a row collecting ticks to test for disease-causing pathogens, according to the article. They have found about five times as many ticks this year as last year, which Gardner said is likely related to an unusually large number of small mammals in the park last summer and is not necessarily indicative of a larger trend. “So, the good news is that next year we might have lower tick densities because small animal populations go through natural cycles, and this year we are seeing relatively few small mammals,” said Gardner. “But there certainly has been a trend statewide and in Acadia of increasing abundance of black-legged ticks and cases of tick-borne illness over the past 20 years.” Sandra De Urioste-Stone, an assistant professor of nature-based tourism at UMaine, also is involved in the study, looking at how Acadia visitors are or are not protecting themselves from ticks. Gardner expects to have findings to share from the study in about six months, according to the article. The Portland Press Herald published the article.