I'm far from an expert, but I have turkey vultures around my house, and the ones we have here tend to have less feathers on their head. Maybe that's just for some of them or in some cases? Ours have enough of a featherless head though that you can see the red/pink even when they're gliding pretty high up.
Interesting, this one looked a lot more bald in person. Its a pretty zoomed in cell phone photo so I think the low contrast hides the feather/no feather line. Still, I was impressed my phone could capture it at all given the distance and lighting.
