eBirdseed.com Wild Bird Feeding Blog

Hi,

Ever wonder how fast those jumpy, herky-jerky birds flit about? It looks like the grackle photo below might offer some insight...

Let's see what we can do with this picture...

• The NovaBird camera used to take this pic has a very fixed focal length of 15 inches. Apparently, the camera focused on the tip of the beak, and hence the weird image above.
• We know that the NovaBird's shutter speed is 1/60 of a second. And in that 60th of a second, the tip of the beak traveled apx 2 inches or .167 ft.
• Grinding out the math, it looks like the grackle is moving its head at about 7 mph. More math suggests that the acceleration involved is something on the order of 10 feet per second squared.
• However, the numbers are misleading... We're assuming that the image reflects uniform acceleration over the 2 inches - a terrible assumption. More accurately, the beak is probably starting at 0 mph, accelerating to about 15 mph in 1/120 of a second, then slowing down to 0 mph in the next 1/120 of a second. That peps things up a bit.
• So just how quick is the movement? Somewhere in the order of a boxer's jab, (though of a considerably shorter duration). Then again, boxers can't jab all day long either.

Well, now that you're bored to tears, here's a respite - a site that is just cool beyond words... Check out USGS National Map Viewer. While it's slower than Google Earth, and really does tax even a high-speed connection, it offers many more features including a topographical option. IMHO, this is a master stroke, and deserves considerable study by serious birders.

And if the USGS didn't bust you out of the doldrums, how about a chickadee?

There... If that doesn't gun your motor, you're probably reading the wrong blog!

See you by those feeders,

CapeCodAlan

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