Monday 6 December 2010

Motion Detecting Bird Feeder Cam

It has been snowing quite a bit recently so despite never having had much success with the birds, I decided to put our bird feeder out. It is hanging from a washing line, well away from any structures that could hide predators. Well, once the snow lady has melted it will be.

Reading and watching Oli Wood's bird feeder webcam inspired me to dig out our "old" digital video camera as well. Our camera is a Canon MVX350i, which has 20x optical zoom, just what's needed to be able to zoom in on the bird feeder at this distance.

The camera is connected to the computer using a Firewire cable, and once I had figured out how to switch off the "auto power save" feature we were good to go.

The camera is directed at the bird feeder using this expensive hand optimized stand:

Because we always only get very few birds on our feeder, I wanted to use motion detection webcam software to take pictures of any birds coming to the feeder. I vaguely remembered a friend using software that took pictures when it detected motion and uploaded them to an ftp server. I don't remember what it was called and hence had no luck finding it.

I did however find open source surveillance software iSpy that appears to do the trick.
Whenever it detects motion it records a bit of video up to a certain length. It has a few settings to change the motion detection and its sensitivity.

The first day I had it running it took a nice bit of video of what I believe is a robin, but completely missed the pair of tits that appeared on the feeder a few minutes later.

Increasing the sensitivity - I think I was increasing it: the slider doesn't mention which we is up or down, so I presume left is down, right is up - only seemed to get me lots of video of the wind blowing the feeder about, so in the end I stuck to the default sensitivity.

It would probably be better to make sure the bird feeder is rigid by sticking a pole in the ground and up its bottom, and increase the sensitivity. The pole should stop the wind blowing the feeder about, while the increase in sensitivity should pick up even the most delecate of birds.

One nice touch is that iSpy buffers the frames, so that when it detects motion it can use a bit of buffered video so you get all of the action, and not just the bird disappearing. It would otherwise possibly have missed this coal tit flying in:

The video of the robin is unedited. I trimmed about a minute of feeder waving about off the end of the coal tit one.

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