Cranes have among the largest non-vocal communication repertoires in the animal kingdom. Body language is exceedingly important. Here are a few Sarusy gestures that other cranes would know the meaning of instantly.
Cranes' large body size and incredible physical prowess poses a great risk of physical injury should they need to joust physically each time a disagreement occurs. Non-vocal postures with specific meaning, like the three above, are a safer alternative for all concerned.
(Photographs information: Top: 10 Jul 2008, Mainpuri district; middle: 28 Nov 2008, Etawah district; bottom: 07 Sep 2009, Farrukhabad district.)