I agree with the others about cropping, you've really got to just try it, until you are happy with the results. You might even find that you can get a couple of images out of the one photo.
The other thing that I do now as part of my workflow is resize my images to be 800px wide (or tall), so my friends and family can see them comfortably on their computer screen. So I've set my crop tool up to be 800px wide by 533px high. Now when I drag the crop box onto my image, I can move the box around and drag the corners to make the crop box bigger or smaller until I'm happy with where it's going to crop, I then double click and I've got my 800px wide image (I'm not sure what editing software you have, I'm using Photoshop CS5, but I think you can do something similar if you have Photoshop Elements - I've just checked and yes you can
http://www.youtube.com/watch?v=7eaUBrEK1_w).
With your image you might also want to try reducing the brightness and increase the saturation, to bring out the colours in the tail feathers and make the chicks stand out a bit more (I hadn't noticed them on the small image).
Regards
Nick