Hippy Steve (@[email protected])

Say what now?!? When a predator like a lion walks through the grasslands, it makes its presence known by roaring, which can be heard miles away. Since the lion is at the top of the food chain, it doesn’t particularly require privacy. But for animals like deer, making loud sounds isn’t exactly the safest way to communicate. So, to get noticed, deer mark areas with rubs and scrapes, known as signposts. Now, a new study in Ecology and Evolution reports that these signposts hold a hidden glow, and other deer can see it. https://newatlas.com/biology/forests-glow-uv-light-deer-communication/ To investigate how the environment might glow in response to animal behaviors, the lead author of the study, Daniel DeRose-Broeckert, and his colleagues surveyed an 800-acre area in the Whitehall Forest and located white-tailed deer’s (Odocoileus virginianus) active signposts. The team marked those signposts with flagging tapes and GPS points. From the sites, they analyzed 109 antler rubs, 37 scrapes, and 20 urinated spots. The light measurements revealed that these markers emit light in wavelengths that stand out against the surrounding environment when exposed to ultraviolet (UV) rays. In an interview DeRose-Broeckert told us that deer are more sensitive to blue wavelengths and UV light than humans. A deer’s eye sensitivity picks up the wavelengths emitted by the glow, i.e., 450-460 nm and 537 nm ranges. Also, deer are most active at dawn and dusk, when the sunlight is low and visible light fades, making ultraviolet wavelengths more prominent.