I've had a vague idea for this for some time, but at last I figured out how I wanted to do it. What was holding me back before was finding the right stock for a foundation.
After starting with two basic people-stocks, I defined several places with white lines, and then free-handed all of the details that are obviously not part of the original photographs. The annoying background was just me being dumb.
Dunno if I've said (on dA) yet, but the title is a reference to the habits of birds and a Sigur Rós song.
The font is My Fair Cody, from dafont