Friday, August 04, 2006

Animation of flying Pileated Woodpecker

An aid for interpreting videos of large flying woodpeckers...

I studied the Pileated flight videos frame-by-frame, which actually give a quite good study of the species at every stage of the wingbeat from multiple angles. I also examined references on bird flight mechanics. From this I created this sketchy, hand-drawn animation of a pileated in flight. This shows a bird flapping continuousy, as the do initially when just flushed from a tree, viewed from the side and behind, at HALF SPEED. It compares directly with a de-interlaced 30 fps digital video, such as the Luneau video from Arkansas. It is slow motion (1/2) when compared to a regular interlaced 30 fps video such as the Nolin video and most of the Cornell videos. The loop shows two wingbeats (the same 10 frames played twice); download it and play it as a loop, or click through it frame-by-frame, as you please.

220 kB quicktime video here

Notes --

The flight mechanics in these videos were actually quite consistent during the segments after the immediate post-launch stroke (where the bird is rotating and attaining proper attitude), and before the bird begin its approach to the next perch. The wingbeat I animated is one of typical speed; both faster and slower ones occur.

In the rear views, the wing surface visible in every frame except for the two upstroke frames (numers 9 and 10), and including the full upward extension frame (number 1), is the underside.

Actual woodpeckers are of course never positioned exactly like this relative to observers or cameras.

When I have a chance I will put together some additional animations that relate directly to the 2005 Arkansas "Mystery Bird."

Same comment rules as before; thanks.


At 5:17 AM, Anonymous Don Crockett said...

Nice sketches!

A quick scanning tip. If you put a piece of black paper on top of the page you want to scan, there will be less bleed through of material printed on the reverse side of the page.

Good to see that you are reusing paper though :) .


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