Odd or not, it's fascinating


One of the bird feeders in my back garden is tall and slim, When it's windy the feeder swings back and forth as I'm 
sure yours do. Any birds feeding when this happens ignore it and continue with their meal. A few days ago I saw a 
solitary robin on the lower tray which is there to aid pigeons - I'm sure most of you are familiar with them.

While most birds seem to maintain there pose when the feeder is moving, this robin didn't.

The feeder was swinging in quite a long arc and the robin looked as if he was enjoying it.

He was facing outward, toward the kitchen window actually, and I had a very good view. As the feeder approached 
the peak of a swing, the robin moved his body in the direction it was about to assume. The same at the other 
extreme. The robin moved his body in anticipation of the reverse direction.

I was convinced that this was deliberate and put me in mind of what we do when on a swing. Moving legs and body in order to maintain the movement by adding kinetic energy to the system.

Has anyone seen this behaviour and would you also think that this was done solely for enjoyment?

It got me thinking about the swing and how motion is sustained. An internet search took me to a very interesting site. The explanation of the swing is much more complicated than I first imagined.

You can see it here  http://www.physicsinsights.org/up_in_a_swing.html

There many more pages I found of great interest on that site, not the least of which is  http://www.physicsinsights.org/iemy/biography-1.htm

  • Hi David, I haven't noticed this behaviour on feeders, but I have seen it on swaying branches, especially with House Sparrows when they are waiting for me to feed them. It's quite comical as they seem to 'ride' the branch as it moves up and down as well as back and forth. As for whether they enjoy it, I couldn't say. However, you would imagine that they would move if it was an unpleasant experience. The more we observe birds, the more questions we ask. That's certainly how it seems!