The pic that you can see, when you go to the review mode on the LCD is heavily sharpened, so that it seems to be in focus when viewing onto the LCD of the camera.
If you want to see, if it's really sharp, then go into the review mode , switch to the pic you want to see and then zoom the pic at 6x or 4x, whatever your camera is beeing able to in the review mode, and scoll the pic to the birds eye. If it's sharp at maybe 6x, there are good chances that it is sharp on your computer monitor too.
There is no other way, to check the photo just after the shot.
I know that problem, you shoot birds, at the display they look great, and at home at the monitor then comes the big disappintment. To Zoom in the review mode seems to be the only way to control the shot...
Greetz,
Gerd