After a long time pondering if these were birds with luxuriant hair or birds with head feathers that bear an uncanny resemblance to hair, the only logical conclusion seems to be they are birds wearing wigs.
I spend an awful lot of time at work drawing, mainly when I should be paying attention to something else. I usually throw everything away with my notepads, so I thought that sharing it with a largely inexistent (and in weeks to come, I'm sure, unimpressed) audience would be a good way to save some of the stuff.