CHAPEL HILL - Deer caused 5.4 percent of all reported driving accidents across the state in 1998, according to a new University of North Carolina study of N.C. motor vehicle accident records. Total crashes involving deer grew by more than 3 percent from the previous year, the analysis showed.
Such mishaps often result in extensive and expensive body damage to cars, but cause few injuries compared with other crashes, UNC Highway Safety Research Center investigators say.
"Undoubtedly these are underestimates of the number of deer-motor vehicle crashes since records are generated only when police officers write reports about crashes and include the word 'deer' in them," said Dr. Donald Reinfurt, deputy director of the center. "Because there's less than $1,000 damage and no injuries, many accidents in which the animals played a role simply were not reported."
In 1994, police described about 8,000 automobile accidents involving deer, said Reinfurt, who conducted the research with computer analyst Eric A. Rodgman. In 1998, officers described 11,503, up from 11,129 in 1997. Complete records for 1999 are not yet available.
Some N.C. counties, especially in the mountains, had few "deer crashes" in 1998, he said. Eastern counties showed the highest rates overall. In Caswell County, for example, deer caused 176 of 478 accidents, or 37 percent.
Other counties with particularly high rates included Tyrrell, Hyde, Jones, Perquimans, Greene, Warren, Chatham, Franklin, Duplin and Washington. Those with the lowest were Graham, Jackson, New Hanover, Buncombe, Mecklenburg, Haywood, Henderson and Swain.
Fall and early winter see half of all deer crashes, which Reinfurt called "repair shops' bread and butter," researchers found. Half happened on county roads, a quarter on state roads, 17 percent on U.S. routes and only a small percentage on interstates and in towns. Almost three-fourths occurred between 6 p.m. and 6 a.m.
"Only about 8 percent of these accidents caused injuries to the driver or passengers, while about 46 percent of non-deer crashes resulted in injuries," Reinfurt said. "Still, we recommend that people drive slower at night where deer are likely to be, and if you see one run across the road, slow down because usually others are in the vicinity."
N.C. Division of Motor Vehicles' records are useful because they enable researchers to study police narratives via computer and thus discover recurring driving problems, he said. Few states have such good computerized records.
"The fact that police officers take the time and make the effort to write that a deer was involved has been very helpful and has made this study possible," Reinfurt said.
Only in about 2 percent of deer crashes did the investigating officer indicate that speed or alcohol was a factor, Reinfurt said. Usually speed or alcohol is a contributing factor in nearly 45 percent of single-vehicle accidents.
Drivers ages 26 to 65 constitute 72 percent of those involved in deer accidents, as opposed to 59 percent of those involved in all single-vehicle mishaps, he said. In other words, drivers younger and older than that have fewer such accidents than one would predict based on other records.
"Overall, about two-thirds of drivers in single-vehicle crashes are male, and the rest are female," Reinfurt said. "In deer crashes, 57 percent of the drivers are male, and 43 percent are female."
North Carolina's deer population now stands at about 950,000, according to Scott Osborn, big game program coordinator at the N.C. Wildlife Resources Commission. In 1910, only 10,000 deer roamed the state, and in 1980, there were about 350,000.
Besides the 216,000 deer taken by hunters in 1998, unknown thousands of others die after being hit by cars and trucks, Osborn said.
"I estimate that between 10,000 and 12,000 deer are killed on highways each year, out of a total deer mortality of about 315,000," he said. "In a lot of accidents, deer are not killed and often not even injured."
Peak months for deer movement -- like auto accidents involving deer -- are October, November and December, Osborn said. Normally gregarious bucks become aggressive and territorial during the fall rut, driving away younger bucks.
"In 1995, we peaked at about 1,039,000 deer, and our deer herd has been fairly stable for about the last five years," he said. "The increasing number of accidents involving deer likely is due to a combination of factors, the most important of which is a steady increase in the number of vehicle miles driven on North Carolina highways each year."
Other factors affecting deer and traffic accidents are more roads and gunfire during the hunting season that keeps the animals moving, he said.
"Between summer and fall, the deer diet changes as well," Osborn said. "They go from eating chiefly grass and leaves to acorns, corn and other crops. That carbohydrate diet gives them more energy and makes them more active. My guess is that the number of accidents involving vehicles and deer will go down next year as a result of hemorrhagic disease, which has been more common in deer this past year, and a bumper crop of acorns, which means they don't have to move around as much."
Research at the University of Georgia and less formal experiences of the N.C. Highway Patrol indicated that deer whistles don't seem to have any effect in reducing the chance of collisions with deer, the wildlife biologist said. Often the high-frequency whistles emit no sound at all or make noise beyond a deer's hearing capability.
"It's better to just save your money," Osborn said.
Note: Reinfurt can be reached at (919) 962-8719 (w). He has data on deer crashes for every N.C. county. Osborn, who works out of his home, can be reached at (919) 776-6017 or via e-mail at osbornjs@interpath.com .
HSRC Contact: Emily Smith, (919) 962-7803.
News Services Contact: David Williamson, (919) 962-8596.