Collared Dove close up

This young Dove was sat at the feeder.So thought,let's see how close it will let me get?
 About 8 feet was the answer.So I went back to get my trusty D800 + Sigma 150-500 and walked back steadily.
   It sat there and I raised the camera.Thinking,OK ! When the shutter fires it'll be gone.
  To my dread and horror the shutter wouldn't fire as I was within the minimum focus distance? I had to actually step back until it focused(2.4 mts) and fired. Still it sat there.Not too worried.
  So during a ''Birdie'' conversation and a few whistles,as you do like,with my friendly Dove.I managed to get 20 or so ''Very'' close shots of this very friendly bird!  Amazing experience to say the least.