Syndicate content

Archive - Jul 10, 2018

Date

Risk of Tick-Borne Diseases in Oak-Dominated Forests in US Is Strongly Tied to Fluctuating Acorn Supply and Structure of Predator Community

In the eastern US, risk of contracting Lyme disease is higher in fragmented forests with high rodent densities and low numbers of resident fox, opossum, and raccoons. These are among the findings from an analysis of 19 years of data on the ecology of tick-borne disease in a forested landscape, published online on May 8, 2018 in Ecology. The article is titled “Tick‐Borne Disease Risk in a Forest Food Web.” Lyme disease is the most frequently reported vector-borne disease in the US. "Using nearly two decades of data on the forest food web, we were interested in untangling the ecological conditions that regulate the number of infected ticks in the landscape," explains Dr. Richard S. Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies in Millbrook, New York, and one of the paper's lead authors. Long-term data were collected in Dutchess County, NY, an epicenter for Lyme disease. Variables monitored at six forested field plots (2.2 hectares each) on the grounds of the Cary Institute included: small mammals, blacklegged ticks, tick-borne pathogens, deer, acorns, and climate. Predator communities and tick infection rates were also recorded at 126 sites throughout Dutchess County over two years. Dr. Taal Levi of Oregon State University, also a lead author, notes, "Our goal was to identify ecological indicators that could be used to protect public health. By analyzing these long-term data holistically, we can tease out how changes in things like predator populations and food resources shift the community structure of the forest ecosystem, and ultimately the abundance of infected blacklegged ticks searching for a meal." Blacklegged ticks take a single blood meal at each of their three life stages: larva, nymph, and adult.