Speculations surrounding feathers, fins, and fantasy

This afternoon I watched some large birds, probably vultures, riding an updraft above a four-lane highway. They were probably at least 100 feet in the air, their wings apparently motionless as they made lazy circles in the sky.

 

Since it was not windy, I was led to speculate about the nature of the updraft. It seemed clear the sun was shining on the dark, smooth surface of the road which heated up and then, in turn, warmed the air above it. Following the laws of physics, the air rose, drawing in cooler air from the surrounding fields, which was then also heated.

 

The birds, of course, had no need to understand any of that. They simply opened their wings and rode the upward wave.

 

Down below, I speculated about the shape of the wave–Once the air had risen far enough to be away from the influence of the heated roadway, did it just sort of collapse and fall back down only to be heated again?

 

Thinking of the birds up on top, had they just been flying along and happened to come across the updraft–or do big birds like that go searching for air currents to ride on. Walking up a hill is hard work, so how tiring is it for birds to keep themselves in the air? Yes, it looks easy from down below, but that’s probably a combination of ignorance and jealousy on my part, since I sure would like to be able to ride the sky like that.

 

Trying to imagine what the birds experience, the closest analogy I could draw comes from swimming.

 

In a way, fish can fly.

 

That is, they move freely at any distance above the bottom of the lake and, as far as they know, the water’s surface is where the atmosphere ends. I wonder, does it cost them any more effort to swim upward than downward?

 

I know from keeping my feet in the water while our pontoon moves around the lake that there are warmer and cooler patches with a surprising contrast in the temperatures my toes encounter. Sometimes downright warm, sometimes chilly enough to make me lift my feet–or at least exclaim in surprise.

 

Do fish notice all that variation? Do they seek out the warmer patches, and do they ever find the water too warm? I know biologists can probably list off which fish thrive most in which water temperatures, but I find myself wondering whether fish seek out those temperatures…or go looking for “updrafts” in the water…or get “short of breath” when exerting themselves.

 

But back to my point.

 

As birds fly through the air, are they encountering cooler and warmer patches the same way my feet do on the pontoon? 

 

It’s not the answers to these questions that’s important, it’s the opportunity to speculate. It’s a little like the jokes my family shares when we put a fish back in the water–if fish can communicate, do all the other members of the school think their “classmate” is a little strange when it tells stories of a whole world up in “space” peopled by bizarre, gigantic creatures who don’t even have scales or fins?

 

There’s lots of humor to be found in creating the theoretical conversation. “Don’t listen to Pumpkinseed…he hasn’t been the same since he ate that shiny worm two summers back…”