The number of dead deer along a stretch of Interstate 80 near the Platte River has dropped by 85 percent since completion of a $1.4 million deer fence in late 2011.
The Nebraska Department of Roads, in consultation with the state Game and Parks Commission, designed the fence to reduce deer-vehicle collisions, which have risen at alarming rates in Nebraska and across the nation. It is the first project of its kind in Nebraska.
The decrease in the number of dead deer was a key finding in a preliminary report looking at road kill and deer-vehicle collisions before and after construction of the 4-mile fence between the Mahoney State Park interchange and Pflug Road.
Eight-foot-high electric and non-electric fences were installed to prevent deer from crossing the interstate, pushing them to move along the river valley and use six "undercrossings" built as part of the interstate expansion between Lincoln and Omaha.
"We're just realizing how important it is to put in a fence with an undercrossing. You can't do one without the other," said Brian Johnson, an interstate designer for the Roads Department.
Johnson said the project may become a model for others.
Between 2003 and 2009, traffic on U.S. roads increased 7 percent, while deer-vehicle collisions rose 18.3 percent, according to a State Farm Insurance study.
Nebraska and New Jersey led the nation with 54 percent increases in deer-vehicle collisions. The average cost of a deer-vehicle collision in 2009 was $3,000, according to State Farm.
Nebraska's new study shows deer mostly move through the valley late from night to early morning, Johnson said, also the prime time for deer-vehicle collisions.
The 13-page report was prepared by University of Nebraska-Lincoln School of Natural Resources researchers Scott Hygnstrom, Aaron Hildreth and William Lawyer III.
Lead investigator Hygnstrom cautioned that a reduction in dead deer doesn’t necessarily mean fewer deer-vehicle collisions.
"You might think there might be a one-to-one relationship between road kill and deer-vehicle collisions, but we don't know for sure until we look at the data," he said.
The research team plans to analyze six months of accident reports from the Nebraska State Patrol.
Hygnstrom said the Roads Department has agreed to extend the study for another year so it can get a broader picture of the effectiveness of the deer fence. The original $120,000 study examined deer-vehicle collisions for the seven years before the fence was built through June 30, 2012.
Reports collected by the Roads Department between May 1, 2009, and Dec. 31 also were part of the study and recorded the date, location, species, sex and ages of all animals killed on the road.
"In essence, we don't want to jump to conclusions here, but it appears the fences have been very effective in reducing deer-vehicle collisions," Hygnstrom said.
Many people who drive between Lincoln and Omaha have told him they've noted a remarkable reduction in the number of dead and live deer on the interstate.
"Most people are perceiving that the fences are working," Hygnstrom said. "We currently lose about 200 people in the U.S. on highways due to deer-vehicle collisions. Efforts like this increase public health and safety, and that makes it a feel-good project."
He noted there were 1.23 million deer-vehicle collisions in the nation last year. More than 12,000 were reported in Nebraska in 2011-12.
Fifteen motion-activated, infra-red cameras installed to monitor deer movement through underpasses and at fence ends generated about 3 million digital images that researchers reviewed over about six months.
In addition to deer, the cameras caught raccoons, opossums, coyotes, red foxes, bobcats, skunks, badgers, house cats, groundhogs, cottontail rabbits, Canada geese, wild turkeys, great blue herons, barred owls and even mice.
Hygnstrom said that's no surprise because the under-crossings were built to serve all wildlife -- not just deer. He said the under-crossings not only increase human safety by keeping wildlife off the interstate but minimize fragmentation of habitat areas along the river.
Other findings from the report:
* Road kill and deer-vehicle collisions were most common in June and November and least common December-April and July-October.
* Deer use of undercrossings was highest in June and November and lowest December-May.
* Cameras recorded 12,532 deer during the study period; 11,901 in undercrossings and 631 around fence ends.
* Deer crossings per month were noticeably lower during the last 14 months of the study. Researchers believe an outbreak of epizootic hemorrhagic disease in Nebraska contributed to the decrease because an overall decline in the local deer population.
* "Wing" structures placed at fence ends were effective in deflecting deer away from the interstate.