Does anyone know...

[Designer]

And nobody had to die in this thread!

 

[baturn]

Ityped a response and it disappeared!
Tyler - sometimes I'm a bit dim, well alot of the time. will try to keep up.
To all - I am not rejecting your suggestions, but to my limmited Knowledge, mating rituals, aggresiveness and nest protection all in volve movement. These birds are perfectly still for several minutes before resuming normal behaviour.

 

[BlackSheep]

That's really strange, especially given the range of bird breeds you've seen it happen to.
Does it only happen when they are at that one location?

 

[DarkShadow]

It could be a way of bringing there body temp down in warm or hot climates. http://www.stanford.edu/group/stanfordbirds/text/essays/Temperature_Regulation.html

 

[Aloicious]

its hard to see what exactly they're doing in stills, but I've seen a number of birds fluff/puff themselves up in the sun, sometimes flapping/moving their wings, turkey vultures, chukars, finches, etc. I never knew what it was, we were observing some vultures doing it far off in the distance on a birding trip I was on and the biologist that was leading the group said they were simply stretching and warming themselves in the sun rays...basically relaxing. I've never seen them have their beak open when doing it, but thats kindof what it looks like to me.

Bird Sunning - Why Do Birds Sunbathe