I just started the "comprehensive bird biology" course and in the first chapter course material it shows videos of the Greater Sage Grouse males doing their mating behavior and territorial stance on the leks.  After watching the first video with the Club-Winged Manakin, I really want to know how the males make their movement and sound with their chest area.  It's not a big sound, but I swear I'm hearing something when they make the movement.  Even more though, I want to know what exactly I'm seeing pop out of the white when they do their display.  It looks like some sort of thicker skinned area than I am used to on birds and is definitely way more stretched out of a neck area on the males than the females. I've not done a lot of sitting and watching various song or game birds' habits or displays.  I've always been more hands-on.  I'm an animal trainer, wildlife educator (been educating on birds of prey the past 20+ years), a master falconer, and (more recently) a certified animal aromatherapist (specializing in birds).  I've had birds since I was 4 years old. If anyone has taken this course and knows that it is actually discussed or shown more in a later chapter, please let me know.  My curiosity has just gotten the best of me after seeing that video tonight and I'm anxious for the answers. Thanks!