I know it's been almost a month since you posted this, but if you haven't found the Rock Drake nests there is about 5 total that I have come across. The nests aren't quite like what you see in Aberration and are simply tucked off to the sides of the path in the radiation zone. The first one is not far from the entrance into the radiation zone shortly after to turn and take the path to get down to the artifact. The actual nest doesn't seem to show for this egg, but it always spawns regardless. Just follow the path and keep your eyes open and look off to the sides in nooks and cranny's. I'm pretty sure I've only found 5 nests, but they consistently spawn eggs so the limited number hasn't been a problem.

Never Mind located several, 42 59 is one, the key is to not look for a next or egg, but to look for a giant rock ficture in the side of the cliff that ficture has the nest