Why doesn't wind drag a hovering Kestrel bird backwards?

[Emmanuel Pil]

I know it's all about drag and lift, but why doesn't the wind drag this bird backwards?

 

[PeroK]

Not an answer, but one of the greatest British films of the 1960's was:

https://en.wikipedia.org/wiki/Kes_(film)

 

[Baluncore]

I know it's all about drag and lift, but why doesn't the wind drag this bird backwards?

Because the bird was slope soaring. The camera was on a structure. Wind was forced upwards, over the structure, so the bird was gliding forwards relative to the airflow, while maintaining its altitude.

 

[russ_watters]

Wind was forced upwards, over the structure, so the bird was gliding forwards relative to the airflow, while maintaining its altitude.

And downwards relative to the airflow.

 

[Emmanuel Pil]

If the answer is: wind blowing upwards and bird gliding downwards relative to the airflow, I just don't see the right angle of the bird's wings. Something awkward here.

 

[Baluncore]

And downwards relative to the airflow.

Yes, gliding.

I like the way birds fix their head orientation, while the body flexes and changes orientation with the moving perch, or the movement of the air. In this case, the bird is also using the camera, or part of the structure, as a local position reference. I believe it was holding its head steady, so it could detect movement (of mice?) on the ground.

The Kestrel was soaring, offset from the camera, so the airflow structure was significant in extent. It would be interesting to know what and where that structure was.

A Google search gave Snetterton Circuit, built at the old RAF Snetterton Heath, Norfolk, England. There is a 5-metre-high grassy ridge built along the north of the track, probably for spectators. Along the crest is a fence, near the western end is a small shed with a 5-metre-high mast for the camera, revealed only by a shadow on 8/2020, (a rare image taken when the Sun was out). So the Kestrel was soaring the slope of the ridge, while fixing its position by flying near the camera on the mast. It was slope soaring, probably hunting the entire length of the ridge, but only a few seconds of video from near the camera was presented. The mast is located at; 52.46700°, 0.940278°.

 

[Emmanuel Pil]

So here is another one above open water. What now?

 

[berkeman]

So here is another one above open water. What now?

Where was the beach interface to the water (hint: it wasn't open water)? Why do I ask that question?

 

[berkeman]

If the answer is: wind blowing upwards and bird gliding downwards relative to the airflow, I just don't see the right angle of the bird's wings. Something awkward here.

Are you hoping for something supernatural here? The bird is taking advantage of the wind currents; there is no magic or supernatural stuff going on, obviously.

 

[Baluncore]

So here is another one above open water. What now?

That bird is slope soaring on the sea breeze, in air rising up the gentle slope of the beach and the dunes.

Many oceanic seabirds soar on the wind, where it rises up the face of ocean waves.

 

[Emmanuel Pil]

It's not fair to make a joke out of it. Of course, there is a logical answer to this. I just do not consider the answer that the bird uses an upward windblow the correct one. See here a tern hovering above a river. No hills, no dunes.

 

[Baluncore]

I just do not consider the answer that the bird uses an upward windblow the correct one.

Rising air is often used by birds to reduce the energy cost of flying.
Apart from rising air, or mystic magic, what alternative is there?

 

[Emmanuel Pil]

Well, maybe I'm on the wrong forum. Thanks anyway.

 

[Baluncore]

See here a tern hovering above a river. No hills, no dunes.

But the shoreline is where the photographer stands, and the shore must be rising ground. The wind only needs to blow diagonally onto the shore to rise.

 

[berkeman]

Well, maybe I'm on the wrong forum. Thanks anyway.

No, no! Please don't leave! We can give you the answers that you want...