Most of the time the big wading birds collect old dead sticks. They wander around on the ground searching for the perfect one.
Once in a while a fresh, soft, stick must be needed. These birds are not master builders so they may not have any particular reason why.
However, when they go for a new stick it’s a really big production.

Even with two hands it’s not easy to break off a stick. One beak twisting and tugging can take forever.