Miller has been investigating the physiology of deer vision and hearing, in part because it may be possible to exploit those senses to minimize deer-vehicle collisions. Working with Gerald Jacobs, an expert on mammalian vision at the University of California, Santa Barbara, the researchers determined which wavelengths of light deer can see. Using sedated white-tailed and fallow deer, they measured the retina’s sensitivity to various wavelengths following a pulse of light into each deers’ eye.

They found that deer see colors much as humans do, but with red-green color blindness. “Deer might have a hard time picking a ripe tomato from a green vine, and the red taillights of a car would probably appear black to a deer,” Miller said. “On the other hand, deer may be able to see blue even better than we do.”

Doctoral student Gino D’Angelo now is mapping the rod and cone cells of the deer retina to better understand the animal’s night and color vision. He also has studies under way using trained fawns to find out how deer focus at different distances and then what shapes and patterns they can perceive.

Miller said he hopes this research may lead to more effective roadside reflectors that reduce deer-vehicle collisions.

That would be especially important in states like Georgia, where development continues to encroach on deer habitat. According to the Georgia Department of Natural Resources, about 14 percent of the state’s annual collisions are caused by deer. Nationwide, deer-vehicle collisions cost about $1 billion, according the National Highway Traffic Administration.

Miller and D’Angelo have teamed up with Bob Warren, a UGA wildlife ecologist, and George Gallagher, an animal science professor at Berry College, to evaluate wildlife warning reflectors and other devices.

Their unique approach takes the deer’s point of view, Warren said. Other researchers have tested whistles and reflectors along roadways by counting dead deer before and after placing the devices.

“Nobody has looked at how deer react to different colors, different sounds and what kind of sounds and colors they can perceive,” Warren said. “We want to see how deer react to these different mitigation techniques or devices placed along the roadway when a vehicle approaches.”

One manufacturer claims that their reflectors collect light from oncoming vehicle headlights and distribute the light along the roadway to create a visual barrier of color and light that stop deer from crossing a road. The researchers are testing amber, red, blue-green and white reflectors.

“We use infrared cameras to watch the deer at night along roadways and see how they respond to the reflectors,” D’Angelo said. The results of the study, which was sponsored by the Georgia Department of Transportation, will be released by the end of the summer.

In collaboration with UGA audiologist Al De Chicchis, D’Angelo and the deer research team also are looking at how deer hear. By exposing sedated deer to a range of sound frequencies, they can get an idea how sensitive a deer’s hearing is by measuring responses in the brainstem. Early studies show that deer detect higher frequencies than humans, although it appears that humans hear most frequencies a little better, he said.

The next step is to figure out how deer respond in the field. A sound that stimulates brainwaves may not necessarily prompt a behavioral response. “We will take this information from the lab and apply it in the field,” D’Angelo said. “We’ll see how deer respond along roadways to different sound-deterrent devices, such as deer whistles or other devices on the market and other sounds that we’ll derive.”