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.

 

Thanks for the Memories

Black-billed MagpieAs a naturalist, I pride myself in my knack for noticing the beauty in the most mundane of things, from rocks and lichen to a leaf on the ground, to pigeons wheeling about an old warehouse. Still, sometimes I fall into the trap of glazing over something I see everyday.

Magpies are one of those things. When doing bird counts or other surveys, I’ll notice them, but it’s a passing glance and a quick mark of ‘BBMA’ in the notebook that is then quickly forgotten. I’m actually quite embarrassed by this, because magpies are truly remarkable birds.

Part of the corvid family, along with jays, ravens and crows, magpies are changelings and rogues. Their dapper, pied plumage give them almost a formal look that seems befitting of the solemn shadows of the winter forest. Then they flit out into the open and the sunlight transforms them into a dazzling creature, shimmering with greens, blues and reds, like the twinkling lights of last week’s Christmas tree. The structure of their plumage refracts the light, revealing the colours hidden beneath the surface.

That’s not all these birds hide. There’s also a brain under those feathers agile enough to rival the great apes and cetaceans. Like the rest of its family, magpies are not your typical bird brains. Firstly, their brain-to-body mass ratio is actually about the same as that of chimpanzees and dolphins and only just slightly less than that of humans. They possess episodic memory, being able to remember not only where they hid their latest food find, but when they stashed it.  If my knack for constantly losing my keys and pencils is any indication, they might actually be swifter than your average human

Having a good memory is an excellent foundation on which to build intellect. Remembering that the local dog likes to chase birds means that if you bring a friend the next time, one can lure the dog away while the other steals some of its dinner, switching off so everyone gets a turn. Memory allows you to be innovative. If you can remember what does and doesn’t work each time to try something, it’s easier to come up with new ideas.

Magpies are definitely one of the foremost innovators of the avian world, using an array of complex social cues to communicate knowledge of things like resource locations and tool use through generations. Most remarkably, they also appear to be able to remember themselves. These pied pipers are one of the few non-human species who have been shown to pass the ‘mirror test’. It’s an easy test; researchers put a brightly coloured dot under the bird’s beak, in a place where they can only see it if they look in a mirror. More often than not, the magpie will see the dot and try and get it off.

So what does this sense of self mean for a bird? How does it affect their relationship with the world around them? Until we learn to speak Magpie, I doubt we’ll ever know. Still, just taking the time to watch them can yield a lot of insight, whether we completely understand it or not. I know I will always be mystified by one memorable morning when it was revealed to me to just how aware these birds are.

When I was teaching vertebrate diversity labs, our instructor took my fellow TA and I for a walk on campus with a stuffed magpie under his arm. In a clearing, he placed it on the ground. I then watched, astounded, as the local birds quickly began to assemble, edging closer to their fallen compatriot, circling the study skin while bobbing their heads up an down in what could only be described as a display of respect, much like what is observed in elephants. I know many of you are probably thinking that they were just eyeing up their next meal, but they made no move to tear at the carcass and I’ve now seen this behaviour several times with my classes.

Throughout of my scientific career, I’ve been warned against the dangers of ‘anthropomorphism’, of ascribing ‘human’ traits and motivations to the animals we study. While I do realize different brains process things differently, I think we do ourselves a disservice by maintaining that we are somehow fundamentally different than the rest of the organisms we share this world with.  Evolution has been working from the same box of crayons for millennia, remixing the colours as situations dictate. I personally feel it’s rather arrogant of us to think we’re the only ones out there who can claim awareness. So, in this season of resolutions, I’m going to remind myself to take a little more time to appreciate those everyday companions that are so easily taken for granted, to make an effort to see the world through their eyes. I think I could learn a lot from them.