Moved from Scarab, Stag and Bess Beetles.

Moved from ID Request.

For me, the easiest way to identify the common species of white grubs is the raster pattern. This is the pattern of cetae or "hairs" on the underside of the rear of the grub. Unfortunately I can't see them here. Here is a link to an online Ohio State University extension publication about turf insects. Clicking on the "White grub raster patterns" link takes you to a great photo showing the raster patterns in detail. There's also a good photo of the grubs themselves ("white grub larvae" link).

The brown spots by the head, the darkened spiracles on its side, and the size make me suspect that this is most likely a Green June beetle larva, but maybe someone else might chime in.

Ironically, if this grub were alive, its behavior might be used to confirm it is a Green June beetle, because these often "walk" on their back when on the surface of a substrate rather than using their feet. That they do this - and that they more often feed on or near the surface than other white grubs - also hints that this might be a Green June beetle. A shrike would be more likely to see or find a grub nearer to the surface.

So if I were the betting type, I'd put my money on Green June beetle.