I know about eagles vortexing upwards on thermals. When other birds, like terns, whip and vortex around at sunset, for example, are they riding on low thermals? What is the air doing as it's churned up by their movements?
2006-12-23 11:12:15 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Zoology
Bob, thanks. You're the best. Have you seen models of what the air is doing during that tern behavior, without the images of the birds in the graphics? And, how does the function of the birds' behavior and the atmosphere affect the local ecology and global ecology? Is that known, yet? (I couldn't e-mail you, yet. Your address is not confirmed.)
2006-12-23 12:13:35 · update #1
As an avid birdwatcher, I have indeed noticed around sunset they do tend to come flocking, I'm not so sure about vortex's, it's more of a stampede :) (howdy)
2006-12-24 01:22:09 · answer #1 · answered by Ringo G. 4 · 1⤊ 0⤋
The aerodynamics of an eagle and tern couldn't be any more different. Eagles soar at very low speeds, while terns are much faster. I'm just basing this on personal observation, but it seems that terns often fly by pointing into a headwind, and the wind velocity keeps them afloat. That's why terns can more or less stay in place without much wing flapping, and large water bodies usually have winds for at least part of the day. So, in terms of vortex behavior, wind velocity substitutes for wing beats, and the type of vortex would be similar to a continuous vortex if there were no wind and the terns were flying at a high rate of speed. It also looks like terns keep adjusting their lift in wind by rotating just the tips of their wings, and they seem to have much more dexterity in their wings than an eagle - on the other hand, I might be completely wrong.
2006-12-23 11:59:55 · answer #2 · answered by formerly_bob 7 · 1⤊ 0⤋