Can Deer See Green Light? What Deer Vision Research Says About Hunting Lights

Short answer: yes, deer can see green light. Red is the color deer are least able to detect, while green falls close to the peak sensitivity of one of their two cone types. That still makes green a useful scanning color for hunters, as long as you use it with discipline. How you handle a light matters about as much as its color.Here is what the research actually says, and how to put it to work on a dark morning.

How deer see color

Deer do not see the world the way we do. People have three types of color-sensing cones; deer have two, which makes them dichromats.

• Short-wavelength (blue) cone: a 1994 study of white-tailed deer retinas by researchers at UC Santa Barbara and the University of Georgia found one cone type most sensitive around 455 nm, in the blue part of the spectrum.
• Middle-wavelength cone: the second cone peaks around 537 nm, in the green range.
• Rods for low light: deer rods peak near 497 nm (blue-green). Rods do most of the work at dawn, dusk, and night, when deer are most active.
• No long-wavelength (red) cone: deer lack the cone that lets us pick out reds and oranges, so those colors don't stand out to them the way they do to us.

Later behavioral testing with trained deer backed this up: deer are more sensitive to shorter wavelengths and less sensitive to longer ones, with some sensitivity reaching into ultraviolet. That is one reason many hunters avoid washing camo in detergents with UV brighteners.Deer eyes are also built for low light. A rod-rich retina and a reflective layer behind it (the source of eyeshine) help them pick up dim light and movement long after we lose detail.

Can deer see green light at night?

Yes. Green sits near the peak of the deer's middle-wavelength cone and close to their rod sensitivity, so a green light is not invisible to a deer, and it does not simply fade into gray. A deer probably doesn't experience green as the vivid color we see, but it can clearly detect a green light, especially once its eyes are adjusted to the dark.Seeing a light is not the same as fleeing from it. In a 2006 USDA study, researchers shined green and blue lasers at deer in fields at night, and deer were no more likely to run than when no laser was used. That tells you green light is not automatically alarming. It does not make a green light "safe" to put on a deer: a beam that sweeps, flickers, or lingers on an animal can still put it on alert.

Red or green light for deer hunting?

Each color has a job:

• Red: the least visible color to deer. If you are asking what color light deer can't see well, red is the answer. Use it for walking in, climbing into the stand, and close work with gear. The trade-off is that red gives your own eyes less detail at distance.
• Green: visible to deer, but human eyes are most sensitive near green, so you get more usable brightness and detail for the same output. That makes green a good choice for scanning a food plot, field edge, or trail from a distance.
• White: the brightest option and the easiest for deer to notice. It includes the blue wavelengths deer see well. Save it for tasks away from deer and for safety.
• Blue and UV: these fall where deer vision is strongest. Avoid them around deer.

Before you use any light at night, check your state's rules. Many states restrict using lights to spot or hunt deer.

Beam discipline matters as much as color

The right color used carelessly still gives you away. A few habits make more difference than the lens:

• Go dim. Use the lowest setting that gets the job done.
• Point it down. Light the trail at your feet or ahead of the tires, not the treeline.
• Keep it brief. On, check, off. Don't leave a beam burning while you fiddle with gear.
• Scan past, don't stare. If you pick up eyeshine, move the beam off the animal instead of holding on it.
• Skip strobe and flicker modes. Flashing light draws attention.
• Mind the rest of your approach. Time your entry, watch the wind, and keep your route consistent.

Light is only one signal: a quiet approach matters too

Deer also pick up sound, scent, and movement, often before they ever see your light. An engine rattling down the trail or exhaust drifting ahead on the wind can undo careful light discipline.That is where a quiet electric approach helps. A Trail Buggy® electric hunting UTV has no engine noise and no exhaust smell, so you can get closer to the stand with less disturbance before finishing on foot. Quiet does not replace field craft, but it removes one of the loudest parts of the morning. For how an electric hunting UTV compares with a gas side-by-side and a hunting e-bike on the way in, read Quiet Access to the Stand.Trail Buggy® offers dual-color light bars with red or green modes, so you can match the color to the job: red for the walk in and the least visible light around deer, or green for scanning plots and field edges. The same beam-discipline rules apply either way: dim, brief, and pointed down.

The bottom line

Deer can see green light. Red is the least visible color to deer, green is visible but useful for scanning at distance, and white and blue are the easiest for deer to notice. Whatever color you choose, keep it dim, brief, pointed down, and off the animal, and pair it with a quiet approach.To see how Trail Buggy® is built for quiet hunting access, visit trailbuggy.us or call 864-410-0410.

Sources

• Jacobs, G.H., et al. (1994). Electrophysiological measurements of spectral mechanisms in the retinas of two cervids: white-tailed deer and fallow deer. Journal of Comparative Physiology A 174:551-557.
• VerCauteren, K.C., et al. (2006). Green and blue lasers are ineffective for dispersing deer at night. Wildlife Society Bulletin 34:371-374.
• VerCauteren, K.C., et al. (2003). Red lasers are ineffective for dispersing deer at night. Wildlife Society Bulletin 31:247-252.