Fresh Whitetail Rubs and Scrapes Glow Like ‘Highway Reflectors’ to Deer, University of Georgia Study Finds
Identifying rubs and scrapes in the field is a skill that hunters develop over time, often remaining elusive to newcomers. However, for whitetail deer, recognizing these territorial markers is far easier due to their acute olfactory senses and the abundant scent they leave behind. New research suggests that fresh rubs and scrapes also visually stand out to deer under ultraviolet (UV) light, effectively glowing in the forest environment.
University of Georgia Deer Lab Shares New Insights on Deer Vision
Researchers at the University of Georgia Deer Lab, renowned for their work on deer sensory biology, recently announced findings through the National Deer Association that highlight the role of UV reflectance in deer communication.
Unlike humans, who perceive a limited light spectrum and largely filter out UV light, deer exhibit up to 20 times greater sensitivity to UV wavelengths. This enhanced vision likely aids them in detecting subtle environmental signals invisible to the human eye.
Experimental Approach to Understanding Deer Signaling
Graduate research assistant Daniel DeRose-Broeckert designed an experiment to quantify how deer perceive their rubs and scrapes under UV light. Using specialized UV illuminating devices, he examined 109 fresh rubs and 37 fresh scrapes in Georgia’s deer habitats during pre-rut and rut periods.
Measurements with a spectrometer showed that:
- Fresh rubs exhibit a stronger glow during the pre-rut phase.
- Fresh scrapes become more luminescent during the rut.
DeRose-Broeckert described this phenomenon to the National Deer Association by comparing rubs to “highway reflectors” for deer, highlighting how these areas stand out visually when the surrounding forest dims in light.
Biological Mechanisms Behind the Glow
The glow effect results from photoluminescence in certain plant materials and deer gland secretions:
- Exposed bark layers and tree sap fluoresce under UV light, which freshly created rubs expose.
- Secretions from the buck’s forehead gland, deposited during rubbing behaviors, also exhibit photoluminescence.
Additionally, both the sap and gland secretions release distinctive chemical scents, allowing rubs to serve dual roles as visual and olfactory signals for territorial communication among whitetails.
Observations on Scrape Luminescence During Rut
While initial assessments found scrapes less reflective under UV light in the pre-rut, this changed during the rut when deer behavior intensifies. Fresh scrapes, marked with urine as part of scent marking, emit a strong glow when illuminated with 365 nm UV light, making them more noticeable to deer navigating these social signals.
This fluorescence likely reinforces scrape visibility during key breeding periods, facilitating communication about dominance and reproductive status within deer populations.
Conclusion
This research from the UGA Deer Lab adds to the understanding of how visual and chemical signals operate in tandem within deer territories. It emphasizes the complexity of deer sensory capabilities and enriches existing knowledge of their behaviors during critical phases like the rut.
Additional reporting and sources from: Rubs and Scrapes Glow Like ‘Highway Reflectors’ to Deer, New Study Shows | Outdoor Life
