Looks to be a big crop. Why did you use only 185mm? I think the high ISO was unnecessary. I have seen some very clean files from D3 at ISO 1000. I have heard D300 is good as well. Harshad or Mital can comment about the high ISO files of D300. I have heard that D90 is not as good as D300 as the noise reduction blurs away details.

The top and bottom of the frame is too close to the bird and needs more space.

Cheers,
Sabyasachi