The fabled North American man-beast, Bigfoot, continues to draw interest after two centuries of searching—despite the lack of a specimen and an utter absence of fossil evidence. Proponents continue to rely on such questioned evidence as photos and films, footprints, hair specimens, and the like.
Although Bigfoot is reported as active in both daytime and nighttime, the popular Animal Planet show Finding Bigfoot emphasizes the latter. This allows the show to imitate Ghost Hunters, using the dark for spooky effects and borrowing the often repeated phrase, “Did you hear that?!”
In addition to trying to pass off animal screams and other calls as Bigfoot, the show promotes the notion that they sometimes encounter “glowing” eyes. They really mean “shining,” since mammals do not exhibit biolumninescence in the eyes or elsewhere. Over time, numerous alleged Bigfoot eyewitnesses have reported such eyeshine. While the color may go unstated, some have described it as amber, green, blue, or other color (Barackman 2017).
However, Bigfoot is most frequently reported to have red eyeshine (Barackman 2017). Indeed, a list of 1002 Bigfoot sightings, 1818–1980 (Bord and Bord 2006), offers several nocturnal reports giving eyeshine, beginning with “glowing red eyes” in northern California in 1952. In all, from 1952 to 1980, I find 48 reports of “glowing” or “shining” or “luminous” eyes, among them some that are red (24 cases, including one “glowing pink”); white, yellow, or unstated (15); green (8); and blue (1).
Many animals exhibit eyeshine. That is because of their tapetum lucidum, a mirrorlike membrane behind the retina that reflects light back through it, allowing the animals to see better in the dark. Now, notwithstanding the unrelated “red-eye effect” in photos of people (due to the camera’s flash reflecting from the retina), neither humans nor the great apes (unlike primitive apes such as lemurs) have tapetums. That would seem to preclude Bigfoot eyeshine, given that it is generally supposed to be some type of large bipedal primate.
Many of the cases could represent bears, I think, considering that bear eyeshine is consistent with the reports. That of the brown bear can show in photos as yellow to yellow-orange, while some witnesses describe red or green; black bear eyeshine can also appear yellow to orange, although red is sometimes reported. Color variations can be due to certain nutrients, for example, as well as iris color and lens distortion (“Ask” 2017).
The eyeshine should be considered in combination with other descriptors. If those do not indicate a possible bear (say an upright-standing hairy beast), or if eyeshine is the only feature seen, one should consider other animals. For instance, a seemingly tall creature with bright red eyeshine might be a barred owl perched on a limb. Again, the least likely possibility for a creature with eyeshine would seem to be Bigfoot.
Ask a bear: What color are your eyes at night? 2011. Online at https://www.backpacker.com/stories/ask-a-bear-what-color-are-your-eyes-at-night; accessed September 19, 2017.
Barackman, Cliff. 2017. Thoughts on Bigfoot Eye Shine. Online at http://cliffbarackman.com/research/articles-2/bigfoot-eye-shine-hypothesis/; accessed September 19, 2017.
Bord, Janet, and Colin Bord. 2006. Bigfoot Casebook Updated. N.p.: Pine Winds Press.