Hummingbird antiques

On the afternoon on 6 May 2010, as I enetered my office, looking over the North field through the window, I saw a hummingbird doing the U-shape dives characteristic of their display to woo a female of their species. It did it about half a dozen times. By then I had my camera out and started to take a video. Managed one ascent and one descent and the bird was gone. I continued the video panning the area for 15 seconds, and then every now and then looked outside the window hoping it will come back, but I did not notice it.

Only the first couple of seconds of the video contained the hummingbird. I give here two links. The first has first 4 seconds of the original video. At 25 frames per second. The second one is a slowed down version where I took the first 49 frames (=2 seconds) and inserted a delay of 0.2 seconds between successive frames to make the second movie. The stripping was done using:

mplayer -vo png hummingbird1.mpg

The recombining was done using:

convert *[0-4]?.png hummingbird2.mpg

I had expected the length to be 48*0.2+29*0.04=10.76 but the second one turns out to be almost 14. So someone is messing up somewhere. Anyway, remember that the actual duration for the second one is 2 seconds.

Its best to download the movies and watch them since over the internet the frames may not flow smoothly. In both, the hummingbird is seen on the right side, first going up and then coming down.

Hummingbird (original, truncated to 4 seconds) 0.5 MB

Hummingbird (with delay between frames - duration 2 seconds)2 MB

From the frequency of hummingbirds here I would have thought its Anna's, but consulting The Sibley Guide to Birds
and remembering how chracteristic U's were being described, could it be a Calliope's? Caltech's weekly data will not support that, nor will their typical habitat. Comments welcome.

BTW, Hummingbirds are amazing birds. They weigh only a few grams (below 5) and everyday eat in food (mostly fluids) several times their bodyweight and need to incessantly feed so as not to die of starvation. What they CAN do is slow down their metabolism (in torpor, a hibernation-like state) by amazingly reducing their heartrate to well below 100. The usual rate - during feeding - is around 1200. Some species are known to fly non-stop for over 500 miles.

Oh, and about the dives: research has shown that hummingbirds can reach 9G during the dives. Jet pilots would pass out at such accelerations. The birds can cover 400 times their bodylength in a second, twice bettering falcons and jets.