Sounds of Silence

White-tailed deerWalking through the winter woods I can’t help but feel an overwhelming sense of closeness with the world around me. Snow is nature’s greatest silencer, muting the world as it bathes it in white and it’s this silence that breeds a feeling of intimacy with my forest brethren. Shrouded by heavy bows and intermittent shadows, I feel my senses stretch through the quiet, reaching out for any sign that I’m not alone in my wanderings.

As I make my silent progress, I find myself wondering how the other inhabitants of the forest perceive this winter world. Whenever I get into one of these moods, my mind usually strays to the white-tailed deer, a species I’m fortunate to meet often on my woodland rambles.

We’re about the same size, a doe and I, and their soft, forward-facing eyes and expressive faces make them easy to relate to.

Though I know she could easily outrun me (especially since I’m a rather slow runner, even for a human), we have a bit more in common than we might first realize. White-tailed deer and humans perceive the world in much the same way. Deer, for the most part, are just a lot better at it.  They have to be. When you live you life under the constant threat of predation, it’s in your best interest to develop a sophisticated arsenal of early-warning systems and deer have plenty.

In deer, the nose knows everything that’s going on around them. With over 290 million olfactory receptors, deer can detect the faintest whiff of danger, even more accurately than their canine pursuers (who only have about 220 million). Both, however, seriously outstrip humans, with our rather paltry 5 million. Where do they put them all? The nasal region of both cervid and canine skulls is actually quite long and full of thin bones in a delicate scroll-work called nasal turbinates. In the living creature, these bones are covered with olfactory epithelium (skin with scent receptors) that picks up the tiniest of molecules. When actively sniffing, they fill their nasal cavities with as much air as possible, giving scent molecules a better chance of being picked up.

To further improve things, deer have a small, fluid-filled sack lying just on top of the palette called the vomeronasal organ (or Jacobson’s organ). This seems to function in a very specific type of scent detection – pheromones, something most mammals use in abundance and deer are no exception.  Whether we have such a functioning organ too is still being debated, but there is evidence that suggests it might play a subtle role in our lives.

Whenever I come face-to-face with a deer, I’m always drawn in by those liquid doe-eyes and this is one place where we have a bit of an edge over our four-legged friend, at least when it comes to how we see our world. Most people will tell you that mammals, especially ones that are active in the dark, don’t see colour. That’s not entirely true. The retina of deer eyes do have cones (colour receptors); they just can’t quite distinguish the same spectrum. A deer’s world is tinted in blues and greens, which makes sense, considering their main concern is picking out the right plants to eat. Still, don’t think you’re invisible to them as you walk through the woods in a blaze-orange vest. Recent work has found that they can pick out at least a hint of these longer wavelengths and with a visual range of 300 degrees while standing still and eyes that are highly sensitive to the slightest movement, a deer will notice you long before you even know you’re not alone.

Besides, if the eyes fail them, the ears wont. No matter how carefully I tread, I know that somewhere, the crunch of my footsteps is being collected by the large, rotating pinna of a deer’s ear. Their range of hearing is considerably better than ours, picking out much higher frequencies than we could ever hope to detect. The wide placement of the ears on the head and their ability to rotate them independently also make it possible for a deer to triangulate the source of a sound, much like an owl.

I know that I will never experience the world on the same level as any of my fellow forest inhabitants, but on a silent, snowy afternoon, I can’t help but want to try.