Well, based on what my runners do, the mohawk and the open mouth are telling you that you make them very nervous for some reason.
It could be that they are trying to protect something or someone, or that they are anxious.
Things that can make them anxious include nutritional deficiencies (not enough of the right vitamins and minerals), changes in their environment, recent trauma and stress, not being used to being near you.
Poultry vitamins in their water, and quiet time near them gently tossing treats around yourself would address the first and last of those possibilities.
Look around and see if there is evidence of predators trying to get into their shelter at night. That could put them in a BAD mood.
I only make eye-contact if I give them some snack. They keep an eye on you. If I pass them close I make sure not to look at them directly from close, that can make them nervous. However, today I made some closed top shelter for them (winter is coming) and I used the loudest powertools near them (2-2.5m). They clearly did not gave a poop (well, oh yes they did, later, on the floor when I was finished with the shelter), swimming and flapping their wings happily in the water.
Also, when I sit near them in silence, and the neighbour's dog comes close to the fence, I make a soft curly whistle - they know that I am with them because I gave alert.