Relationships among hosts, habitats, and ticks throughout Alabama
Ticks are the foremost parasites of wildlife and humans in the United States, and may transmit pathogens associated with Lyme disease, Ehrlichiosis, spotted fever Rickettsiosis, and others. Despite the high occurrence of several species of ticks throughout Alabama, little is known about their distribution or the degree to which they carry pathogens. Consequently, the probability of encountering infected ticks in the state is unknown. For this project, we environmental and climatic factors that affect tick and pathogen distribution and risk, and determined relationships among habitats, ticks, pathogens, and hosts. Ticks were trapped for one year (5/16-5/17) on 105 plots in deciduous, coniferous, pasture, early successional, and residential areas throughout Alabama. Hourly forest floor temperature and relative humidity were recorded on the same sites. In preliminary pathogen screenings, minimum infection rates in lone star ticks ranged from 0% to 3% for Ehrlichia spp. and 17% to 49% for Rickettsia amblyommii. Interestingly, the minimum infection rate of Rickettsia parkeri in Gulf coast ticks was 18%, and no ticks tested positive for Borrelia spp. Additionally, during the summers of 2015 to 2017, 762 ticks were collected from 125 white-tailed deer in 19 counties, and 3,302 ticks were collected from 626 deer on 12 Wildlife Management Areas during two successive winters from 2015-2017. Pathogen screening for these samples is in progress. Preliminary analyses show that across all locations and land uses, minimum and range of humidity and temperature are the primary drivers of overall tick abundance, and forest floor characteristics and sandy soils have significant effects. Additionally, while only 11% (n=61) of ticks captured on traps were black-legged ticks, 88% (n=2,894) were collected from deer between November to February, elucidating a deer’s critical role in their survival and movement, and suggesting traditional sampling methods for this species are ineffective in the Southeast.