COLLEGE PARK, Md. — Large populations of white-tailed deer can be found all over the east coast, spreading and supporting disease-carrying ticks known to carry Lyme disease and anaplasmosis. It was always assumed that these deer populations primarily live in wooded areas and only pass through neighborhoods at night, but new research reports deer often call it a day and spend the night quite close to suburban areas.
This latest study is a five-year collaborative project between the University of Maryland and USDA. Scientists report that deer in suburban environments often “bed down” and get some shuteye for the evening within 50 meters of residential properties. This is the first ever project to investigate hourly movements of white-tailed deer across different times of day during different seasons.
“We knew deer were in and around neighborhoods, but we didn’t realize just how much they were living in the neighborhoods,” says senior study author Jennifer Mullinax, assistant professor in the UMD Department of Environmental Science & Technology, in a university release. “A big takeaway from this study is that neighborhoods are the home range of suburban white-tailed deer. Agencies monitoring and estimating suburban deer populations may be missing a huge part of the population if they focus their monitoring efforts only on deer in wooded parks and undeveloped areas, because a lot of the deer are actually living in the neighborhoods, especially at night and in winter.”
These findings offer important guidance for suburbanites looking to lower their risk of tick-borne illnesses. More deer in residential areas more often means more ticks and an increased risk of exposure for anyone living nearby. Removing deer or treating areas where deer are known to stay the night can help reduce tick populations significantly.
“We used to think people mostly got Lyme disease when they walked in the woods,” Prof. Mullinax explains, “But recent studies have shown they’re getting Lyme disease in their own backyards, and now that we know the deer are living right there too, it makes more sense.”
The research team captured and collared 51 deer from five local parks in the Howard Country, Maryland metro area. That region is a highly suburban area featuring residential neighborhoods, schools, businesses, and open spaces or undeveloped land. The collars attached to the deer featured GPS trackers that kept note of the animals’ locations on an hourly basis for 62 to 116 weeks (1.19 to 2.23 years).
That investigation led to the finding that deer tend to avoid residential areas during the day, but move in when the sun goes down. This was especially true during winter. The deer then sleep close to the edge of various lawns and yards surrounding houses and apartment buildings. On average, 71 residential properties placed within female core range, and another 129 residential properties placed within male core range.
Study authors hope this research helps communities, households, and individuals better protect themselves from tick-borne diseases.
The study is published in Urban Ecosystems.