Fresh Deer Rubs and Scrapes Shine Like Reflectors, New Research from UGA Reveals
Deer hunters and wildlife enthusiasts have long known rubs and scrapes as key indicators of whitetail activity, yet spotting these signs remains a skill that improves with experience. A new study from the University of Georgia Deer Lab brings fresh insight into why these markings are so prominent to deer.
While humans often need sharp eyes and practice to detect fresh rubs and scrapes, whitetails rely on more than just their senses – they perceive visual signals invisible to the human eye. Researchers confirm that fresh rubs and scrapes emit a glow in ultraviolet (UV) light, effectively acting as natural “highway reflectors” for deer.
Understanding Deer Vision and UV Sensitivity
Deer see the world differently from humans, particularly in their ability to detect UV light. The National Deer Association reports that deer are approximately 20 times more sensitive to UV light than humans, who largely cannot perceive this part of the spectrum.
This heightened UV sensitivity is biologically significant for communication and survival, and it appears scientists at UGA utilized this by examining how rubs and scrapes reflect UV wavelengths.
The UGA Experiment and Its Findings
Graduate researcher Daniel DeRose-Broeckert conducted an experiment during the pre-rut and rut seasons in Georgia, shining different UV lights on 109 fresh rubs and 37 fresh scrapes in the wild. Using a spectrometer, he measured the spectral emissions to assess visibility within the deer’s visual range.
Results indicated fresh rubs show increased luminescence especially during the pre-rut, with scrapes glowing more intensely during the rut. This timing aligns with key behavioral phases of whitetails, suggesting an evolved method of communication through both sight and scent.
Biological Factors Behind the Glow
Several natural materials contribute to this fluorescence. Layers of bark and plant saps can photoluminesce when freshly disturbed, while secretions from a buck’s forehead gland add a unique chemical signature that also fluoresces under UV light.
These dual signals—visual fluorescence combined with distinct scents—likely serve multiple communicative purposes:
- Marking territorial boundaries
- Signaling reproductive status
- Facilitating individual recognition among bucks
DeRose-Broeckert described rubs as akin to “highway reflectors” for deer, emphasizing how the glowing markings stand out distinctly against the darker forest backdrop.
Implications for Wildlife Observation and Management
This discovery enhances understanding of deer behavior and sensory ecology. Wildlife professionals and hunters may further appreciate how deer use visual cues beyond human perception in their social interactions and territorial displays.
Additionally, the combination of chemical and visual signaling highlights the complexity of deer communication strategies during critical seasonal periods.
Visual Evidence Under UV Light
Photographic evidence provided by the National Deer Association shows a fresh scrape illuminated with a 365 nm UV light, where wet leaves saturated with deer urine emit a pronounced glow. This further supports the idea that urine and gland secretions contribute prominently to the signaling process.
Additional reporting and sources from: Rubs and Scrapes Glow Like ‘Highway Reflectors’ to Deer, New Study Shows | Outdoor Life
