Inside of a Dog_ What Dogs See, Smell, and Know - Alexandra Horowitz [86]
This morning I heard her barking in her sleep—the muffled, jowl-puffing bark of dreaming. Oh, does she dream. I love her dream-barks, falsely severe, often accompanied by twitching feet or lips curled into a teeth-baring growl. Watch long enough and I'll see her eyes dancing, the periodic clenches of her jaw, hear her tiny whimpers. The best dreams inspire tail-wags—huge thumps of delight that wake herself and me.
We humans experience the day according to our ideas about what typically or ideally will happen throughout it—what meals, work, play, conversation, sex, commuting, naps—and also according to the cycle of our circadian rhythms. Given our attention to the former, though, we sometimes hardly notice that our bodies are charting a regular course through the day. That midafternoon sleepiness, the difficulty in rising at five in the morning—both are due to our activities clashing with our circadian rhythms. Take away some of those human expectations and you've got the dog's experience: the bodily feelings of the passage of the day. In fact, without the societal expectations to distract them, they may be more attuned to the rhythms of their body telling them when to rise and when to eat. As per their pacemaker, they are most active as dark gives way to dawn, and markedly reduce their activity in the afternoon, with a burst of energy in the evening. With nothing else to do—no papers to shuffle, no meetings to attend—dogs nap straight through that afternoon slowdown.
Even without regular mealtimes the body goes through feeding-related cycles. Right before it is time to eat, animals tend to be more active—running about, licking, salivating—in anticipation of food. We see this food-sense when a dog pursues us relentlessly with panting mouth and appealing eyes. Eventually we figure out it is time to feed the dog.
So in fact one can set the clock by the dog's belly. And, even more impressive, dogs maintain a clock operated by other mechanisms not yet fully understood, which seem to read the day's air. Our local environment—the air in the room we are in—indicates (if we have the right indicator) where we are in the day. Although we do not typically sense it, it is just the sort of thing a dog might notice. If we attend carefully, we might notice the gross changes of the day: the cool at the moment the sun sets, or the time of day registered in the amount of light streaming in the window—but the day's changes are infinitely more subtle than this. With sensitive machinery, researchers can detect the gentle air currents that form as a summer's day ends: warmed air pulled up along the inner walls creeps across the ceiling, spilling into the center of the room and falling along the outer walls. This is no breeze, nor even a noticeable puff or waft. Yet the sensitive machinery that is the dog evidently detects this slow, inevitable flow of air, perhaps with the help of their whiskers, well positioned to register the direction of any scent on the air. We know they can detect it because they can also be fooled: brought into a room that was warmed, a dog trained to follow a scent trail may search first by the windows when the track is really closer to the room's interior.
She is patient. How she waits for me. She waits as I duck into the local grocery store: looking plaintively, then settling down. She