What the dog’s nose knows.
This morning’s dog walk was bright and clear, but a little on the cool side for June. Light jacket and long pants kind of weather. While I like it a bit more towards shorts and t-shirt conditions, Grace, our middle aged Weimaraner, acted like it was perfect. So what made Grace so enthusiastic today? I’m pretty sure it was the 50°F temperature and still air. I suspect it was right in the sweet spot for exercising while wearing a short fur coat and utilizing the canine olfactory sense.
Today we wandered up and down the river park just after dawn, with the dog “nose skimming” in a wide zig-zag pattern. Occasional sneezes interrupted the Grace’s sniff-puff sequence, but then it was right back to the hunt. When a track of interested was interrupted, the pattern changed to something resembling a figure-eight that started tight and grew in size until the scent was regained or abandoned. When we passed someone or something going the other direction, Grace circled behind, nose bobbing up and down in the air, catching a whiff of whatever scent lingered. When the dog was satisfied, it was back to the ground. The scent tracks typically led to trees, bushes, and picnic tables.
Near the end of the walk, approaching the river bank parking lot, the dog zeroed-in on a gentleman fishing from a small gravel beach. I called out “Good morning,” to him, and he nodded in reply and grinned at Grace. Most of the folks out “wetting a line” at that time of day appreciate a proper hunting dog, so they usually greet Grace with a smile and a pat. After collecting a compliment for being a “nice dawg,” Grace lapped some water from the river, and then moved on to investigate the fisherman’s car. In one of those embarrassing dog walking moments, I had to encourage the dog to leave it, which of course was resisted, as Grace’s nose kept skimming along the trunk of the little brown Toyota Corolla. Thankfully, the fellow’s attention was back on fishing, and he didn’t see Grace doing her impression of a police dog. What was in the trunk? I’ll never know, but it was sure interesting to the dog.
After loading Grace in my car for the ride home, I glanced back over at the fisherman’s Toyota. It wasn’t sagging down over the rear wheels, like there was something heavy in the back, so I said to the dog, “Nah. Anyway, that trunk’s not big enough for a dead body.” But that got me wondering. What is it like to sense the world with a dog’s nose and why are some days better than others?
After a bit of reading, the best comparison I could come up with is this: Temperature is to the nose what light is to the eye. As light’s intensity and color change, our eye’s ability to perceive is changed. Not enough and you can’t see, and too much and the details are washed out. For our canine pals, as the temperature changes, the scents given off by matter change, and more importantly the diffusion properties change. The easiest human example I found compared the smells of hot apple pie with cold whipped cream on top. You can smell the pie from a long way away, but the cream is nearly odorless until you get very close. For pups, it means one day there could be lots of strong scents, so much so that it’s just “smell noise.” Other days, only a few distinct scents may be propagating across the landscape. To make it really complex, add barometric pressure, ground and air temperature difference, and random artificial scents. No wonder the dog’s nose has good days and bad days.
All of this led me to wonder why humans are stuck on what we perceive with our eyes, often to the near exclusion of all our other senses? Like scent and taste. I decided that was for another post, but in the mean time, ponder the power of the nose, and maybe get a slice of apple pie at lunchtime.