Here's another captive raptor photo. I don't have the tech specs at the moment but they are roughly the same as the other captive bird photos I've posted recently (Canon 1D Mark III, 100mm macro, stopped down, 3 flash setup, hand held).
Curious to know why you used a macro on this when your aware of the extreme limitation regarding DOF. Is the reason being you wanted a good portion of the image blurred?
There is no extreme limitation regarding DOF when using a macro lens; it's a function of aperture. These were shot with the flash as the main source of light at aperture of something like f/14. Have a look at a couple of other captive birds I've photographed using the same lens and technique. Plenty of DOF.