Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Thursday, July 26, 2007

Eagles in flight - wing and tail control perfect.

My friend Jim (a licensed small plane pilot) will be envious of the flight control demonstrated by these Eagles, which as I mentioned yesterday, were flying around my home , yesterday.
Before I forget, it is of course the Wedge-tailed Eagle (Aquila audax).

In this photo, the bird is flying past, in a wide arc, as it circles anti-clockwise past me. Right wing higher than the left. but all controls more-or-less in "neutral".

Here, the other bird in the pair, is circling (further away), but with the left wing tip swept back, and the right wing tips raised, and slightly flared ("feathered") showing that that wing tip is under greater atmospheric pressure, as it is doing more "work". This is keeping the bird on a steady circling pattern.
The same bird has now abandoned its circling pattern, and is heading away - travelling in a straight line. The two wings are more-or-less equally set, but the central panels of the right wing are being lifted a little by wind pressure. Such subtle controls - much more adjustability than Jim has on his plane.

With fully outstretched wings, this bird is not "flapping" just using the maximum surface area of its wings, by spreading its "fingertips" to open the wings fully, to gain maximum "lift". Also, note that the tail is a deep "V", not just in "shape" (see yesterday's photo - taken from underneath the bird), but also, in sideways profile. In other words the edges of the "V" are higher than the long feathers in the centre of the tail. So, it is using the tail as a rudder, to gain maximum control and "lift".

For the several minutes that these birds were circling around my home, they never actually flapped - they just adjusted their wings and tails, ever so subtly. They adjust them according to the wind conditions, to achieve the desired changes in direction.

Then, they just drifted away, to the east, out over the Escarpment - and away!

Eagle Moon - taken at 4:02 pm, against the wonderful clear sky. It was the perfect complement to these Eagles circling under the brilliant blue sky.

A truly stunning afternoon, on which to watch these wonderful creatures flying around - so free.

Why did they not provide the perfect shot, and fly across the face of the moon? Now, that would have been a Art Photograph! Alas, I shall settle for the experience they did provide me.

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