Fluffy neck

The fluffy neck feathers of these Griffon Vultures confused me for a moment. Why would you have a feather duster for a neck when your entire method of operation is to get your neck inside a carcass and retrieve the tasty bits.

Then I remembered that it was -9 degrees outside in the Rhodope Mountains this morning and I can forgive them a bit of insulation.

Now I’m wondering just how they keep themselves clean. Maybe the carrion they eat being frozen solid helps?